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Power KM, Nguyen KC, Silva A, Singh S, Hall DH, Rongo C, Barr MM. NEKL-4 regulates microtubule stability and mitochondrial health in ciliated neurons. J Cell Biol 2024; 223:e202402006. [PMID: 38767515 PMCID: PMC11104396 DOI: 10.1083/jcb.202402006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 04/10/2024] [Accepted: 05/06/2024] [Indexed: 05/22/2024] Open
Abstract
Ciliopathies are often caused by defects in the ciliary microtubule core. Glutamylation is abundant in cilia, and its dysregulation may contribute to ciliopathies and neurodegeneration. Mutation of the deglutamylase CCP1 causes infantile-onset neurodegeneration. In C. elegans, ccpp-1 loss causes age-related ciliary degradation that is suppressed by a mutation in the conserved NEK10 homolog nekl-4. NEKL-4 is absent from cilia, yet it negatively regulates ciliary stability via an unknown, glutamylation-independent mechanism. We show that NEKL-4 was mitochondria-associated. Additionally, nekl-4 mutants had longer mitochondria, a higher baseline mitochondrial oxidation state, and suppressed ccpp-1∆ mutant lifespan extension in response to oxidative stress. A kinase-dead nekl-4(KD) mutant ectopically localized to ccpp-1∆ cilia and rescued degenerating microtubule doublet B-tubules. A nondegradable nekl-4(PEST∆) mutant resembled the ccpp-1∆ mutant with dye-filling defects and B-tubule breaks. The nekl-4(PEST∆) Dyf phenotype was suppressed by mutation in the depolymerizing kinesin-8 KLP-13/KIF19A. We conclude that NEKL-4 influences ciliary stability by activating ciliary kinesins and promoting mitochondrial homeostasis.
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Affiliation(s)
- Kaiden M. Power
- Department of Genetics and Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ, USA
| | - Ken C. Nguyen
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Andriele Silva
- Department of Biology, Brooklyn College of the City University of New York, Brooklyn, NY, USA
| | - Shaneen Singh
- Department of Biology, Brooklyn College of the City University of New York, Brooklyn, NY, USA
| | - David H. Hall
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Christopher Rongo
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, USA
| | - Maureen M. Barr
- Department of Genetics and Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ, USA
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2
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Vasudevan A, Ratnakaran N, Murthy K, Kumari S, Hall DH, Koushika SP. Preferential transport of synaptic vesicles across neuronal branches is regulated by the levels of the anterograde motor UNC-104/KIF1A in vivo. Genetics 2024; 227:iyae021. [PMID: 38467475 DOI: 10.1093/genetics/iyae021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 07/13/2023] [Accepted: 01/25/2024] [Indexed: 03/13/2024] Open
Abstract
Asymmetric transport of cargo across axonal branches is a field of active research. Mechanisms contributing to preferential cargo transport along specific branches in vivo in wild type neurons are poorly understood. We find that anterograde synaptic vesicles preferentially enter the synaptic branch or pause at the branch point in Caenorhabditis elegans Posterior Lateral Mechanosensory neurons. The synaptic vesicle anterograde kinesin motor UNC-104/KIF1A regulates this vesicle behavior at the branch point. Reduced levels of functional UNC-104 cause vesicles to predominantly pause at the branch point and lose their preference for turning into the synaptic branch. SAM-4/Myrlysin, which aids in recruitment/activation of UNC-104 on synaptic vesicles, regulates vesicle behavior at the branch point similar to UNC-104. Increasing the levels of UNC-104 increases the preference of vesicles to go straight toward the asynaptic end. This suggests that the neuron optimizes UNC-104 levels on the cargo surface to maximize the fraction of vesicles entering the branch and minimize the fraction going to the asynaptic end.
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Affiliation(s)
- Amruta Vasudevan
- Department of Biological Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005, India
| | - Neena Ratnakaran
- Department of Biological Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005, India
| | - Kausalya Murthy
- Neurobiology, NCBS-TIFR, Bellary Road, Bengaluru 560 065, India
| | - Shikha Kumari
- Neurobiology, NCBS-TIFR, Bellary Road, Bengaluru 560 065, India
| | - David H Hall
- Centre for C. elegans Anatomy, Albert Einstein College of Medicine, New York, New York, NY 10461, USA
| | - Sandhya P Koushika
- Department of Biological Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005, India
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Riboul DV, Crill S, Oliva CD, Restifo MG, Joseph R, Joseph K, Nguyen KC, Hall DH, Fily Y, Macleod GT. Ultrastructural analysis reveals mitochondrial placement independent of synapse placement in fine caliber C. elegans neurons. bioRxiv 2024:2023.05.30.542959. [PMID: 37398149 PMCID: PMC10312582 DOI: 10.1101/2023.05.30.542959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Neurons rely on mitochondria for an efficient supply of ATP and other metabolites. However, while neurons are highly elongated, mitochondria are discrete and limited in number. Due to the slow rates of diffusion over long distances it follows that neurons would benefit from an ability to control the distribution of mitochondria to sites of high metabolic activity, such as synapses. It is assumed that neurons' possess this capacity, but ultrastructural data over substantial portions of a neuron's extent that would allow for tests of such hypotheses are scarce. Here, we mined the Caenorhabditis elegans electron micrographs of John White and Sydney Brenner and found systematic differences in average mitochondrial length (ranging from 1.3 to 2.4 μm), volume density (3.7% to 6.5%) and diameter (0.18 to 0.24 μm) between neurons of different neurotransmitter type and function, but found limited differences in mitochondrial morphometrics between axons and dendrites of the same neurons. Analyses of distance intervals found mitochondria to be distributed randomly with respect to presynaptic specializations, and an indication that mitochondria were displaced from postsynaptic specializations. Presynaptic specializations were primarily localized to varicosities, but mitochondria were no more likely to be found in synaptic varicosities than non-synaptic varicosities. Consistently, mitochondrial volume density was no greater in varicosities with synapses. Therefore, beyond the capacity to disperse mitochondria throughout their length, at least in C. elegans, fine caliber neurons manifest limited sub-cellular control of mitochondrial size and distribution.
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Yim H, Choe DT, Bae JA, Choi MK, Kang HM, Nguyen KCQ, Ahn S, Bahn SK, Yang H, Hall DH, Kim JS, Lee J. Comparative connectomics of dauer reveals developmental plasticity. Nat Commun 2024; 15:1546. [PMID: 38413604 PMCID: PMC10899629 DOI: 10.1038/s41467-024-45943-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 02/06/2024] [Indexed: 02/29/2024] Open
Abstract
A fundamental question in neurodevelopmental biology is how flexibly the nervous system changes during development. To address this, we reconstructed the chemical connectome of dauer, an alternative developmental stage of nematodes with distinct behavioral characteristics, by volumetric reconstruction and automated synapse detection using deep learning. With the basic architecture of the nervous system preserved, structural changes in neurons, large or small, were closely associated with connectivity changes, which in turn evoked dauer-specific behaviors such as nictation. Graph theoretical analyses revealed significant dauer-specific rewiring of sensory neuron connectivity and increased clustering within motor neurons in the dauer connectome. We suggest that the nervous system in the nematode has evolved to respond to harsh environments by developing a quantitatively and qualitatively differentiated connectome.
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Affiliation(s)
- Hyunsoo Yim
- Department of Biological Sciences, Seoul National University, Seoul, 08826, South Korea
| | - Daniel T Choe
- Department of Biological Sciences, Seoul National University, Seoul, 08826, South Korea
| | - J Alexander Bae
- Research Institute of Basic Sciences, Seoul National University, Seoul, 08826, South Korea
| | - Myung-Kyu Choi
- Research Institute of Basic Sciences, Seoul National University, Seoul, 08826, South Korea
| | - Hae-Mook Kang
- Research Institute of Basic Sciences, Seoul National University, Seoul, 08826, South Korea
| | - Ken C Q Nguyen
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Soungyub Ahn
- Department of Biological Sciences, Seoul National University, Seoul, 08826, South Korea
| | - Sang-Kyu Bahn
- Neural Circuits Research Group, Korea Brain Research Institute, Daegu, 41062, South Korea
- Cognitive Science Research Group, Korea Brain Research Institute, Daegu, 41062, South Korea
| | - Heeseung Yang
- Department of Biological Sciences, Seoul National University, Seoul, 08826, South Korea
| | - David H Hall
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Jinseop S Kim
- Neural Circuits Research Group, Korea Brain Research Institute, Daegu, 41062, South Korea.
- Department of Biological Sciences, Sungkyunkwan University, Suwon-si, Gyeonggi-do, 16419, South Korea.
| | - Junho Lee
- Department of Biological Sciences, Seoul National University, Seoul, 08826, South Korea.
- Research Institute of Basic Sciences, Seoul National University, Seoul, 08826, South Korea.
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5
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Power KM, Nguyen KC, Silva A, Singh S, Hall DH, Rongo C, Barr MM. NEKL-4 regulates microtubule stability and mitochondrial health in C. elegans ciliated neurons. bioRxiv 2024:2024.02.14.580304. [PMID: 38405845 PMCID: PMC10888866 DOI: 10.1101/2024.02.14.580304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Ciliopathies are often caused by defects in the ciliary microtubule core. Glutamylation is abundant in cilia, and its dysregulation may contribute to ciliopathies and neurodegeneration. Mutation of the deglutamylase CCP1 causes infantile-onset neurodegeneration. In C. elegans, ccpp-1 loss causes age-related ciliary degradation that is suppressed by mutation in the conserved NEK10 homolog nekl-4. NEKL-4 is absent from cilia, yet negatively regulates ciliary stability via an unknown, glutamylation-independent mechanism. We show that NEKL-4 was mitochondria-associated. nekl-4 mutants had longer mitochondria, a higher baseline mitochondrial oxidation state, and suppressed ccpp-1 mutant lifespan extension in response to oxidative stress. A kinase-dead nekl-4(KD) mutant ectopically localized to ccpp-1 cilia and rescued degenerating microtubule doublet B-tubules. A nondegradable nekl-4(PESTΔ) mutant resembled the ccpp-1 mutant with dye filling defects and B-tubule breaks. The nekl-4(PESTΔ) Dyf phenotype was suppressed by mutation in the depolymerizing kinesin-8 KLP-13/KIF19A. We conclude that NEKL-4 influences ciliary stability by activating ciliary kinesins and promoting mitochondrial homeostasis.
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Affiliation(s)
- Kaiden M Power
- Department of Genetics and Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ, United States of America
| | - Ken C Nguyen
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx, NY, United States of America
| | - Andriele Silva
- Department of Biology, Brooklyn College of the City University of New York, Brooklyn, NY, United States of America
| | - Shaneen Singh
- Department of Biology, Brooklyn College of the City University of New York, Brooklyn, NY, United States of America
| | - David H Hall
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx, NY, United States of America
| | - Christopher Rongo
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, United States of America
| | - Maureen M Barr
- Department of Genetics and Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ, United States of America
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Wang G, Guasp R, Salam S, Chuang E, Morera A, Smart AJ, Jimenez D, Shekhar S, Melentijevic I, Nguyen KC, Hall DH, Grant BD, Driscoll M. Mechanical force of uterine occupation enables large vesicle extrusion from proteostressed maternal neurons. bioRxiv 2023:2023.11.13.565361. [PMID: 38014134 PMCID: PMC10680645 DOI: 10.1101/2023.11.13.565361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Large vesicle extrusion from neurons may contribute to spreading pathogenic protein aggregates and promoting inflammatory responses, two mechanisms leading to neurodegenerative disease. Factors that regulate extrusion of large vesicles, such as exophers produced by proteostressed C. elegans touch neurons, are poorly understood. Here we document that mechanical force can significantly potentiate exopher extrusion from proteostressed neurons. Exopher production from the C. elegans ALMR neuron peaks at adult day 2 or 3, coinciding with the C. elegans reproductive peak. Genetic disruption of C. elegans germline, sperm, oocytes, or egg/early embryo production can strongly suppress exopher extrusion from the ALMR neurons during the peak period. Conversely, restoring egg production at the late reproductive phase through mating with males or inducing egg retention via genetic interventions that block egg-laying can strongly increase ALMR exopher production. Overall, genetic interventions that promote ALMR exopher production are associated with expanded uterus lengths and genetic interventions that suppress ALMR exopher production are associated with shorter uterus lengths. In addition to the impact of fertilized eggs, ALMR exopher production can be enhanced by filling the uterus with oocytes, dead eggs, or even fluid, supporting that distention consequences, rather than the presence of fertilized eggs, constitute the exopher-inducing stimulus. We conclude that the mechanical force of uterine occupation potentiates exopher extrusion from proximal proteostressed maternal neurons. Our observations draw attention to the potential importance of mechanical signaling in extracellular vesicle production and in aggregate spreading mechanisms, making a case for enhanced attention to mechanobiology in neurodegenerative disease.
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Wang J, Saul J, Nikonorova IA, Cruz CN, Power KM, Nguyen KC, Hall DH, Barr MM. Ciliary intrinsic mechanisms regulate dynamic ciliary extracellular vesicle release from sensory neurons. bioRxiv 2023:2023.11.01.565151. [PMID: 37961114 PMCID: PMC10635059 DOI: 10.1101/2023.11.01.565151] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Cilia-derived extracellular vesicles (EVs) contain signaling proteins and act in intercellular communication. Polycystin-2 (PKD-2), a transient receptor potential channel, is a conserved ciliary EVs cargo. Caenorhabditis elegans serves as a model for studying ciliary EV biogenesis and function. C. elegans males release EVs in a mechanically-induced manner and deposit PKD-2-labeled EVs onto the hermaphrodite vulva during mating, suggesting an active release process. Here, we study the dynamics of ciliary EV release using time-lapse imaging and find that cilia can sustain the release of PKD-2-labeled EVs for a two-hour duration. Intriguingly, this extended release doesn't require neuronal synaptic transmission. Instead, ciliary intrinsic mechanisms regulate PKD-2 ciliary membrane replenishment and dynamic EV release. The ciliary kinesin-3 motor KLP-6 is necessary for both initial and extended ciliary EV release, while the transition zone protein NPHP-4 is required only for sustained EV release. The dihydroceramide desaturase DEGS1/2 ortholog TTM-5 is highly expressed in the EV-releasing sensory neurons, localizes to cilia, and is required for sustained but not initial ciliary EV release, implicating ceramide in ciliary ectocytosis. The study offers a comprehensive portrait of real-time ciliary EV release, and mechanisms supporting cilia as proficient EV release platforms.
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Affiliation(s)
- Juan Wang
- Department of Genetics and Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ 08854, USA
| | - Josh Saul
- Department of Genetics and Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ 08854, USA
| | - Inna A. Nikonorova
- Department of Genetics and Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ 08854, USA
| | - Carlos Nava Cruz
- Department of Genetics and Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ 08854, USA
| | - Kaiden M. Power
- Department of Genetics and Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ 08854, USA
| | - Ken C. Nguyen
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - David H. Hall
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Maureen M. Barr
- Department of Genetics and Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ 08854, USA
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Kamal M, Tokmakjian L, Knox J, Han D, Moshiri H, Magomedova L, Nguyen KCQ, Zheng H, Burns AR, Cooke B, Lacoste J, Yeo M, Hall DH, Cummins CL, Roy PJ. PGP-14 establishes a polar lipid permeability barrier within the C. elegans pharyngeal cuticle. PLoS Genet 2023; 19:e1011008. [PMID: 37930961 PMCID: PMC10653525 DOI: 10.1371/journal.pgen.1011008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 11/16/2023] [Accepted: 10/05/2023] [Indexed: 11/08/2023] Open
Abstract
The cuticles of ecdysozoan animals are barriers to material loss and xenobiotic insult. Key to this barrier is lipid content, the establishment of which is poorly understood. Here, we show that the p-glycoprotein PGP-14 functions coincidently with the sphingomyelin synthase SMS-5 to establish a polar lipid barrier within the pharyngeal cuticle of the nematode C. elegans. We show that PGP-14 and SMS-5 are coincidentally expressed in the epithelium that surrounds the anterior pharyngeal cuticle where PGP-14 localizes to the apical membrane. pgp-14 and sms-5 also peak in expression at the time of new cuticle synthesis. Loss of PGP-14 and SMS-5 dramatically reduces pharyngeal cuticle staining by Nile Red, a key marker of polar lipids, and coincidently alters the nematode's response to a wide-range of xenobiotics. We infer that PGP-14 exports polar lipids into the developing pharyngeal cuticle in an SMS-5-dependent manner to safeguard the nematode from environmental insult.
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Affiliation(s)
- Muntasir Kamal
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
| | - Levon Tokmakjian
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
| | - Jessica Knox
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
| | - Duhyun Han
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
| | - Houtan Moshiri
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
| | - Lilia Magomedova
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Ken CQ Nguyen
- Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, United States of America
| | - Hong Zheng
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
| | - Andrew R. Burns
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
| | - Brittany Cooke
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
| | - Jessica Lacoste
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
| | - May Yeo
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
| | - David H. Hall
- Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, United States of America
| | - Carolyn L. Cummins
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Peter J. Roy
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
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Arnold ML, Cooper J, Androwski R, Ardeshna S, Melentijevic I, Smart J, Guasp RJ, Nguyen KCQ, Bai G, Hall DH, Grant BD, Driscoll M. Intermediate filaments associate with aggresome-like structures in proteostressed C. elegans neurons and influence large vesicle extrusions as exophers. Nat Commun 2023; 14:4450. [PMID: 37488107 PMCID: PMC10366101 DOI: 10.1038/s41467-023-39700-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 06/19/2023] [Indexed: 07/26/2023] Open
Abstract
Toxic protein aggregates can spread among neurons to promote human neurodegenerative disease pathology. We found that in C. elegans touch neurons intermediate filament proteins IFD-1 and IFD-2 associate with aggresome-like organelles and are required cell-autonomously for efficient production of neuronal exophers, giant vesicles that can carry aggregates away from the neuron of origin. The C. elegans aggresome-like organelles we identified are juxtanuclear, HttPolyQ aggregate-enriched, and dependent upon orthologs of mammalian aggresome adaptor proteins, dynein motors, and microtubule integrity for localized aggregate collection. These key hallmarks indicate that conserved mechanisms drive aggresome formation. Furthermore, we found that human neurofilament light chain (NFL) can substitute for C. elegans IFD-2 in promoting exopher extrusion. Taken together, our results suggest a conserved influence of intermediate filament association with aggresomes and neuronal extrusions that eject potentially toxic material. Our findings expand understanding of neuronal proteostasis and suggest implications for neurodegenerative disease progression.
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Affiliation(s)
- Meghan Lee Arnold
- Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ, 08855, USA
| | - Jason Cooper
- Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ, 08855, USA
| | - Rebecca Androwski
- Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ, 08855, USA
| | - Sohil Ardeshna
- Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ, 08855, USA
| | - Ilija Melentijevic
- Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ, 08855, USA
| | - Joelle Smart
- Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ, 08855, USA
| | - Ryan J Guasp
- Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ, 08855, USA
| | - Ken C Q Nguyen
- Department of Neuroscience, Albert Einstein College of Medicine, Rose F. Kennedy Center, Bronx, NY, 10461, USA
| | - Ge Bai
- Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ, 08855, USA
| | - David H Hall
- Department of Neuroscience, Albert Einstein College of Medicine, Rose F. Kennedy Center, Bronx, NY, 10461, USA
| | - Barth D Grant
- Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ, 08855, USA.
| | - Monica Driscoll
- Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ, 08855, USA.
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Aggad D, Brouilly N, Omi S, Essmann CL, Dehapiot B, Savage-Dunn C, Richard F, Cazevieille C, Politi KA, Hall DH, Pujol R, Pujol N. Meisosomes, folded membrane microdomains between the apical extracellular matrix and epidermis. eLife 2023; 12:e75906. [PMID: 36913486 PMCID: PMC10010689 DOI: 10.7554/elife.75906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 02/23/2023] [Indexed: 03/14/2023] Open
Abstract
Apical extracellular matrices (aECMs) form a physical barrier to the environment. In Caenorhabditis elegans, the epidermal aECM, the cuticle, is composed mainly of different types of collagen, associated in circumferential ridges separated by furrows. Here, we show that in mutants lacking furrows, the normal intimate connection between the epidermis and the cuticle is lost, specifically at the lateral epidermis, where, in contrast to the dorsal and ventral epidermis, there are no hemidesmosomes. At the ultrastructural level, there is a profound alteration of structures that we term 'meisosomes,' in reference to eisosomes in yeast. We show that meisosomes are composed of stacked parallel folds of the epidermal plasma membrane, alternately filled with cuticle. We propose that just as hemidesmosomes connect the dorsal and ventral epidermis, above the muscles, to the cuticle, meisosomes connect the lateral epidermis to it. Moreover, furrow mutants present marked modifications of the biomechanical properties of their skin and exhibit a constitutive damage response in the epidermis. As meisosomes co-localise to macrodomains enriched in phosphatidylinositol (4,5) bisphosphate, they could conceivably act, like eisosomes, as signalling platforms, to relay tensile information from the aECM to the underlying epidermis, as part of an integrated stress response to damage.
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Affiliation(s)
- Dina Aggad
- Aix Marseille Univ, INSERM, CNRS, CIML, Turing Centre for Living SystemsMarseilleFrance
| | - Nicolas Brouilly
- Aix Marseille Université, CNRS, IBDM, Turing Centre for Living SystemsMarseilleFrance
| | - Shizue Omi
- Aix Marseille Univ, INSERM, CNRS, CIML, Turing Centre for Living SystemsMarseilleFrance
| | - Clara Luise Essmann
- Department of Computer Science, University College LondonLondonUnited Kingdom
- Bio3/Bioinformatics and Molecular Genetics, Albert-Ludwigs-UniversityFreiburgGermany
| | - Benoit Dehapiot
- Aix Marseille Université, CNRS, IBDM, Turing Centre for Living SystemsMarseilleFrance
| | - Cathy Savage-Dunn
- Department of Biology, Queens College and the Graduate Center, CUNYFlushingUnited States
| | - Fabrice Richard
- Aix Marseille Université, CNRS, IBDM, Turing Centre for Living SystemsMarseilleFrance
| | - Chantal Cazevieille
- INM, Institut des Neurosciences de Montpellier, Plateau de microscopie électronique, INSERM, Université de MontpellierMontpellierFrance
| | - Kristin A Politi
- Department of Neuroscience, Albert Einstein College of MedicineNew YorkUnited States
| | - David H Hall
- Department of Neuroscience, Albert Einstein College of MedicineNew YorkUnited States
| | - Remy Pujol
- INM, Institut des Neurosciences de Montpellier, Plateau de microscopie électronique, INSERM, Université de MontpellierMontpellierFrance
| | - Nathalie Pujol
- Aix Marseille Univ, INSERM, CNRS, CIML, Turing Centre for Living SystemsMarseilleFrance
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11
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Wang Y, Arnold ML, Smart AJ, Wang G, Androwski RJ, Morera A, Nguyen KCQ, Schweinsberg PJ, Bai G, Cooper J, Hall DH, Driscoll M, Grant BD. Large vesicle extrusions from C. elegans neurons are consumed and stimulated by glial-like phagocytosis activity of the neighboring cell. eLife 2023; 12:e82227. [PMID: 36861960 PMCID: PMC10023159 DOI: 10.7554/elife.82227] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 02/28/2023] [Indexed: 03/03/2023] Open
Abstract
Caenorhabditis elegans neurons under stress can produce giant vesicles, several microns in diameter, called exophers. Current models suggest that exophers are neuroprotective, providing a mechanism for stressed neurons to eject toxic protein aggregates and organelles. However, little is known of the fate of the exopher once it leaves the neuron. We found that exophers produced by mechanosensory neurons in C. elegans are engulfed by surrounding hypodermal skin cells and are then broken up into numerous smaller vesicles that acquire hypodermal phagosome maturation markers, with vesicular contents gradually degraded by hypodermal lysosomes. Consistent with the hypodermis acting as an exopher phagocyte, we found that exopher removal requires hypodermal actin and Arp2/3, and the hypodermal plasma membrane adjacent to newly formed exophers accumulates dynamic F-actin during budding. Efficient fission of engulfed exopher-phagosomes to produce smaller vesicles and degrade their contents requires phagosome maturation factors SAND-1/Mon1, GTPase RAB-35, the CNT-1 ARF-GAP, and microtubule motor-associated GTPase ARL-8, suggesting a close coupling of phagosome fission and phagosome maturation. Lysosome activity was required to degrade exopher contents in the hypodermis but not for exopher-phagosome resolution into smaller vesicles. Importantly, we found that GTPase ARF-6 and effector SEC-10/exocyst activity in the hypodermis, along with the CED-1 phagocytic receptor, is required for efficient production of exophers by the neuron. Our results indicate that the neuron requires specific interaction with the phagocyte for an efficient exopher response, a mechanistic feature potentially conserved with mammalian exophergenesis, and similar to neuronal pruning by phagocytic glia that influences neurodegenerative disease.
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Affiliation(s)
- Yu Wang
- Department of Molecular Biology and Biochemistry, Rutgers UniversityPiscatawayUnited States
| | - Meghan Lee Arnold
- Department of Molecular Biology and Biochemistry, Rutgers UniversityPiscatawayUnited States
| | - Anna Joelle Smart
- Department of Molecular Biology and Biochemistry, Rutgers UniversityPiscatawayUnited States
| | - Guoqiang Wang
- Department of Molecular Biology and Biochemistry, Rutgers UniversityPiscatawayUnited States
| | - Rebecca J Androwski
- Department of Molecular Biology and Biochemistry, Rutgers UniversityPiscatawayUnited States
| | - Andres Morera
- Department of Molecular Biology and Biochemistry, Rutgers UniversityPiscatawayUnited States
| | - Ken CQ Nguyen
- Department of Neuroscience, Albert Einstein College of Medicine, Rose F. Kennedy Center, BronxNew YorkUnited States
| | - Peter J Schweinsberg
- Department of Molecular Biology and Biochemistry, Rutgers UniversityPiscatawayUnited States
| | - Ge Bai
- Department of Molecular Biology and Biochemistry, Rutgers UniversityPiscatawayUnited States
| | - Jason Cooper
- Department of Molecular Biology and Biochemistry, Rutgers UniversityPiscatawayUnited States
| | - David H Hall
- Department of Neuroscience, Albert Einstein College of Medicine, Rose F. Kennedy Center, BronxNew YorkUnited States
| | - Monica Driscoll
- Department of Molecular Biology and Biochemistry, Rutgers UniversityPiscatawayUnited States
| | - Barth D Grant
- Department of Molecular Biology and Biochemistry, Rutgers UniversityPiscatawayUnited States
- Rutgers Center for Lipid ResearchNew BrunswickUnited States
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12
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Tolkin T, Mohammad A, Starich TA, Nguyen KCQ, Hall DH, Schedl T, Hubbard EJA, Greenstein D. Innexin function dictates the spatial relationship between distal somatic cells in the Caenorhabditis elegans gonad without impacting the germline stem cell pool. eLife 2022; 11:e74955. [PMID: 36098634 PMCID: PMC9473689 DOI: 10.7554/elife.74955] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Accepted: 08/08/2022] [Indexed: 12/01/2022] Open
Abstract
Gap-junctional signaling mediates myriad cellular interactions in metazoans. Yet, how gap junctions control the positioning of cells in organs is not well understood. Innexins compose gap junctions in invertebrates and affect organ architecture. Here, we investigate the roles of gap-junctions in controlling distal somatic gonad architecture and its relationship to underlying germline stem cells in Caenorhabditis elegans. We show that a reduction of soma-germline gap-junctional activity causes displacement of distal sheath cells (Sh1) towards the distal end of the gonad. We confirm, by live imaging, transmission electron microscopy, and antibody staining, that bare regions-lacking somatic gonadal cell coverage of germ cells-are present between the distal tip cell (DTC) and Sh1, and we show that an innexin fusion protein used in a prior study encodes an antimorphic gap junction subunit that mispositions Sh1. We determine that, contrary to the model put forth in the prior study based on this fusion protein, Sh1 mispositioning does not markedly alter the position of the borders of the stem cell pool nor of the progenitor cell pool. Together, these results demonstrate that gap junctions can control the position of Sh1, but that Sh1 position is neither relevant for GLP-1/Notch signaling nor for the exit of germ cells from the stem cell pool.
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Affiliation(s)
- Theadora Tolkin
- Kimmel Center for Biology and Medicine at the Skirball Institute, NYU Grossman School of MedicineNew YorkUnited States
- Department of Cell Biology, NYU Grossman School of MedicineNew YorkUnited States
| | - Ariz Mohammad
- Department of Genetics, Washington University School of MedicineSt. LouisUnited States
| | - Todd A Starich
- Department of Genetics, Cell Biology and Development, University of MinnesotaMinneapolisUnited States
| | - Ken CQ Nguyen
- Department of Neuroscience, Albert Einstein College of MedicineThe BronxUnited States
| | - David H Hall
- Department of Neuroscience, Albert Einstein College of MedicineThe BronxUnited States
| | - Tim Schedl
- Department of Genetics, Washington University School of MedicineSt. LouisUnited States
| | - E Jane Albert Hubbard
- Kimmel Center for Biology and Medicine at the Skirball Institute, NYU Grossman School of MedicineNew YorkUnited States
- Department of Cell Biology, NYU Grossman School of MedicineNew YorkUnited States
- Department of Pathology, NYU Grossman School of MedicineNew YorkUnited States
| | - David Greenstein
- Department of Genetics, Cell Biology and Development, University of MinnesotaMinneapolisUnited States
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13
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Katz SS, Barker TJ, Maul-Newby HM, Sparacio AP, Nguyen KCQ, Maybrun CL, Belfi A, Cohen JD, Hall DH, Sundaram MV, Frand AR. A transient apical extracellular matrix relays cytoskeletal patterns to shape permanent acellular ridges on the surface of adult C. elegans. PLoS Genet 2022; 18:e1010348. [PMID: 35960773 PMCID: PMC9401183 DOI: 10.1371/journal.pgen.1010348] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 08/24/2022] [Accepted: 07/18/2022] [Indexed: 11/19/2022] Open
Abstract
Epithelial cells secrete apical extracellular matrices to form protruding structures such as denticles, ridges, scales, or teeth. The mechanisms that shape these structures remain poorly understood. Here, we show how the actin cytoskeleton and a provisional matrix work together to sculpt acellular longitudinal alae ridges in the cuticle of adult C. elegans. Transient assembly of longitudinal actomyosin filaments in the underlying lateral epidermis accompanies deposition of the provisional matrix at the earliest stages of alae formation. Actin is required to pattern the provisional matrix into longitudinal bands that are initially offset from the pattern of longitudinal actin filaments. These bands appear ultrastructurally as alternating regions of adhesion and separation within laminated provisional matrix layers. The provisional matrix is required to establish these demarcated zones of adhesion and separation, which ultimately give rise to alae ridges and their intervening valleys, respectively. Provisional matrix proteins shape the alae ridges and valleys but are not present within the final structure. We propose a morphogenetic mechanism wherein cortical actin patterns are relayed to the laminated provisional matrix to set up distinct zones of matrix layer separation and accretion that shape a permanent and acellular matrix structure.
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Affiliation(s)
- Sophie S. Katz
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, California, United States of America
| | - Trevor J. Barker
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Hannah M. Maul-Newby
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, California, United States of America
| | - Alessandro P. Sparacio
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Ken C. Q. Nguyen
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | - Chloe L. Maybrun
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, California, United States of America
| | - Alexandra Belfi
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Jennifer D. Cohen
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - David H. Hall
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | - Meera V. Sundaram
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Alison R. Frand
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, California, United States of America
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14
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Oliver D, Ramachandran S, Philbrook A, Lambert CM, Nguyen KCQ, Hall DH, Francis MM. Correction: Kinesin-3 mediated axonal delivery of presynaptic neurexin stabilizes dendritic spines and postsynaptic components. PLoS Genet 2022; 18:e1010291. [PMID: 35749355 PMCID: PMC9231799 DOI: 10.1371/journal.pgen.1010291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
[This corrects the article DOI: 10.1371/journal.pgen.1010016.].
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15
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Oliver D, Ramachandran S, Philbrook A, Lambert CM, Nguyen KCQ, Hall DH, Francis MM. Kinesin-3 mediated axonal delivery of presynaptic neurexin stabilizes dendritic spines and postsynaptic components. PLoS Genet 2022; 18:e1010016. [PMID: 35089924 PMCID: PMC8827443 DOI: 10.1371/journal.pgen.1010016] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 02/09/2022] [Accepted: 01/03/2022] [Indexed: 12/02/2022] Open
Abstract
The functional properties of neural circuits are defined by the patterns of synaptic connections between their partnering neurons, but the mechanisms that stabilize circuit connectivity are poorly understood. We systemically examined this question at synapses onto newly characterized dendritic spines of C. elegans GABAergic motor neurons. We show that the presynaptic adhesion protein neurexin/NRX-1 is required for stabilization of postsynaptic structure. We find that early postsynaptic developmental events proceed without a strict requirement for synaptic activity and are not disrupted by deletion of neurexin/nrx-1. However, in the absence of presynaptic NRX-1, dendritic spines and receptor clusters become destabilized and collapse prior to adulthood. We demonstrate that NRX-1 delivery to presynaptic terminals is dependent on kinesin-3/UNC-104 and show that ongoing UNC-104 function is required for postsynaptic maintenance in mature animals. By defining the dynamics and temporal order of synapse formation and maintenance events in vivo, we describe a mechanism for stabilizing mature circuit connectivity through neurexin-based adhesion.
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Affiliation(s)
- Devyn Oliver
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Shankar Ramachandran
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Alison Philbrook
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Christopher M. Lambert
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Ken C. Q. Nguyen
- Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, United States of America
| | - David H. Hall
- Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, United States of America
| | - Michael M. Francis
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
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16
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Schroeder NE, Hall DH. Announcement of WormAtlas partnership with the Journal of Nematology. J Nematol 2021; 53:e2021-90. [PMID: 34761227 PMCID: PMC8571904 DOI: 10.21307/jofnem-2021-090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Indexed: 11/11/2022] Open
Abstract
A detailed understanding of nematode anatomy can be leveraged for the development of new parasitic nematode control strategies and for fundamental biological insights through nematode model organisms. The Center for C. elegans Anatomy, with its websites WormAtlas and WormImage, is the central anatomical resource for researchers studying the model organism Caenorhabditis elegans. Here, we announce our expansion of the WormAtlas and WormImage resources beyond C. elegans to include additional nematode species. Towards this goal, we will partner with the Journal of Nematology to write and solicit anatomically focused review chapters for publication in the Journal and corresponding inclusion on the WormAtlas website.
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Affiliation(s)
- Nathan E. Schroeder
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - David H. Hall
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 14061
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17
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Bauer J, Poupart V, Goupil E, Nguyen KCQ, Hall DH, Labbé JC. The initial expansion of the C. elegans syncytial germ line is coupled to incomplete primordial germ cell cytokinesis. Development 2021; 148:dev199633. [PMID: 34195824 PMCID: PMC8327289 DOI: 10.1242/dev.199633] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 06/25/2021] [Indexed: 01/06/2023]
Abstract
The C. elegans germline is organized as a syncytium in which each germ cell possesses an intercellular bridge that is maintained by a stable actomyosin ring and connected to a common pool of cytoplasm, termed the rachis. How germ cells undergo cytokinesis while maintaining this syncytial architecture is not completely understood. Here, we use live imaging to characterize primordial germ cell (PGC) division in C. elegans first-stage larvae. We show that each PGC possesses a stable intercellular bridge that connects it to a common pool of cytoplasm, which we term the proto-rachis. We further show that the first PGC cytokinesis is incomplete and that the stabilized cytokinetic ring progressively moves towards the proto-rachis and eventually integrates with it. Our results support a model in which the initial expansion of the C. elegans syncytial germline occurs by incomplete cytokinesis, where one daughter germ cell inherits the actomyosin ring that was newly formed by stabilization of the cytokinetic ring, while the other inherits the pre-existing stable actomyosin ring. We propose that such a mechanism of iterative cytokinesis incompletion underpins C. elegans germline expansion and maintenance.
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Affiliation(s)
- Jack Bauer
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, C.P. 6128, Succ. Centre-ville, Montréal, QC H3C 3J7, Canada
| | - Vincent Poupart
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, C.P. 6128, Succ. Centre-ville, Montréal, QC H3C 3J7, Canada
| | - Eugénie Goupil
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, C.P. 6128, Succ. Centre-ville, Montréal, QC H3C 3J7, Canada
| | - Ken C. Q. Nguyen
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - David H. Hall
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Jean-Claude Labbé
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, C.P. 6128, Succ. Centre-ville, Montréal, QC H3C 3J7, Canada
- Department of Pathology and Cell Biology, Université de Montréal, C.P. 6128, Succ. Centre-ville, Montréal, QC H3C 3J7, Canada
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18
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Berghoff EG, Glenwinkel L, Bhattacharya A, Sun H, Varol E, Mohammadi N, Antone A, Feng Y, Nguyen K, Cook SJ, Wood JF, Masoudi N, Cros CC, Ramadan YH, Ferkey DM, Hall DH, Hobert O. The Prop1-like homeobox gene unc-42 specifies the identity of synaptically connected neurons. eLife 2021; 10:e64903. [PMID: 34165428 PMCID: PMC8225392 DOI: 10.7554/elife.64903] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Accepted: 05/17/2021] [Indexed: 12/13/2022] Open
Abstract
Many neuronal identity regulators are expressed in distinct populations of cells in the nervous system, but their function is often analyzed only in specific isolated cellular contexts, thereby potentially leaving overarching themes in gene function undiscovered. We show here that the Caenorhabditis elegans Prop1-like homeobox gene unc-42 is expressed in 15 distinct sensory, inter- and motor neuron classes throughout the entire C. elegans nervous system. Strikingly, all 15 neuron classes expressing unc-42 are synaptically interconnected, prompting us to investigate whether unc-42 controls the functional properties of this circuit and perhaps also the assembly of these neurons into functional circuitry. We found that unc-42 defines the routes of communication between these interconnected neurons by controlling the expression of neurotransmitter pathway genes, neurotransmitter receptors, neuropeptides, and neuropeptide receptors. Anatomical analysis of unc-42 mutant animals reveals defects in axon pathfinding and synaptic connectivity, paralleled by expression defects of molecules involved in axon pathfinding, cell-cell recognition, and synaptic connectivity. We conclude that unc-42 establishes functional circuitry by acting as a terminal selector of functionally connected neuron types. We identify a number of additional transcription factors that are also expressed in synaptically connected neurons and propose that terminal selectors may also function as 'circuit organizer transcription factors' to control the assembly of functional circuitry throughout the nervous system. We hypothesize that such organizational properties of transcription factors may be reflective of not only ontogenetic, but perhaps also phylogenetic trajectories of neuronal circuit establishment.
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Affiliation(s)
- Emily G Berghoff
- Department of Biological Sciences, Columbia University, Howard Hughes Medical InstituteNew YorkUnited States
| | - Lori Glenwinkel
- Department of Biological Sciences, Columbia University, Howard Hughes Medical InstituteNew YorkUnited States
| | - Abhishek Bhattacharya
- Department of Biological Sciences, Columbia University, Howard Hughes Medical InstituteNew YorkUnited States
| | - HaoSheng Sun
- Department of Biological Sciences, Columbia University, Howard Hughes Medical InstituteNew YorkUnited States
| | - Erdem Varol
- Department of Statistics, Zuckerman Institute, Columbia UniversityNew YorkUnited States
| | - Nicki Mohammadi
- Department of Biological Sciences, Columbia University, Howard Hughes Medical InstituteNew YorkUnited States
| | - Amelia Antone
- Department of Biological Sciences, Columbia University, Howard Hughes Medical InstituteNew YorkUnited States
| | - Yi Feng
- Department of Biological Sciences, Columbia University, Howard Hughes Medical InstituteNew YorkUnited States
| | - Ken Nguyen
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of MedicineBronxUnited States
| | - Steven J Cook
- Department of Biological Sciences, Columbia University, Howard Hughes Medical InstituteNew YorkUnited States
| | - Jordan F Wood
- Department of Biological Sciences, University at Buffalo, The State University of New YorkBuffaloUnited States
| | - Neda Masoudi
- Department of Biological Sciences, Columbia University, Howard Hughes Medical InstituteNew YorkUnited States
| | - Cyril C Cros
- Department of Biological Sciences, Columbia University, Howard Hughes Medical InstituteNew YorkUnited States
| | - Yasmin H Ramadan
- Department of Biological Sciences, Columbia University, Howard Hughes Medical InstituteNew YorkUnited States
| | - Denise M Ferkey
- Department of Biological Sciences, University at Buffalo, The State University of New YorkBuffaloUnited States
| | - David H Hall
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of MedicineBronxUnited States
| | - Oliver Hobert
- Department of Biological Sciences, Columbia University, Howard Hughes Medical InstituteNew YorkUnited States
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19
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Samaddar M, Goudeau J, Sanchez M, Hall DH, Bohnert KA, Ingaramo M, Kenyon C. A genetic screen identifies new steps in oocyte maturation that enhance proteostasis in the immortal germ lineage. eLife 2021; 10:e62653. [PMID: 33848238 PMCID: PMC8043744 DOI: 10.7554/elife.62653] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 03/24/2021] [Indexed: 12/24/2022] Open
Abstract
Somatic cells age and die, but the germ-cell lineage is immortal. In Caenorhabditis elegans, germline immortality involves proteostasis renewal at the beginning of each new generation, when oocyte maturation signals from sperm trigger the clearance of carbonylated proteins and protein aggregates. Here, we explore the cell biology of this proteostasis renewal in the context of a whole-genome RNAi screen. Oocyte maturation signals are known to trigger protein-aggregate removal via lysosome acidification. Our findings suggest that lysosomes are acidified as a consequence of changes in endoplasmic reticulum activity that permit assembly of the lysosomal V-ATPase, which in turn allows lysosomes to clear the aggregates via microautophagy. We define two functions for mitochondria, both of which appear to be independent of ATP generation. Many genes from the screen also regulate lysosome acidification and age-dependent protein aggregation in the soma, suggesting a fundamental mechanistic link between proteostasis renewal in the germline and somatic longevity.
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Affiliation(s)
| | - Jérôme Goudeau
- Calico Life Sciences LLCSouth San FranciscoUnited States
| | - Melissa Sanchez
- Department of Molecular and Cellular Biology, University of California, BerkeleyBerkeleyUnited States
| | - David H Hall
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of MedicineNew YorkUnited States
| | - K Adam Bohnert
- Calico Life Sciences LLCSouth San FranciscoUnited States
| | - Maria Ingaramo
- Calico Life Sciences LLCSouth San FranciscoUnited States
| | - Cynthia Kenyon
- Calico Life Sciences LLCSouth San FranciscoUnited States
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20
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Brittin CA, Cook SJ, Hall DH, Emmons SW, Cohen N. A multi-scale brain map derived from whole-brain volumetric reconstructions. Nature 2021; 591:105-110. [DOI: 10.1038/s41586-021-03284-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Accepted: 01/25/2021] [Indexed: 12/16/2022]
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21
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Molina-García L, Lloret-Fernández C, Cook SJ, Kim B, Bonnington RC, Sammut M, O'Shea JM, Gilbert SPR, Elliott DJ, Hall DH, Emmons SW, Barrios A, Poole RJ. Direct glia-to-neuron transdifferentiation gives rise to a pair of male-specific neurons that ensure nimble male mating. eLife 2020; 9:e48361. [PMID: 33138916 PMCID: PMC7609048 DOI: 10.7554/elife.48361] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 10/02/2020] [Indexed: 12/20/2022] Open
Abstract
Sexually dimorphic behaviours require underlying differences in the nervous system between males and females. The extent to which nervous systems are sexually dimorphic and the cellular and molecular mechanisms that regulate these differences are only beginning to be understood. We reveal here a novel mechanism by which male-specific neurons are generated in Caenorhabditis elegans through the direct transdifferentiation of sex-shared glial cells. This glia-to-neuron cell fate switch occurs during male sexual maturation under the cell-autonomous control of the sex-determination pathway. We show that the neurons generated are cholinergic, peptidergic, and ciliated putative proprioceptors which integrate into male-specific circuits for copulation. These neurons ensure coordinated backward movement along the mate's body during mating. One step of the mating sequence regulated by these neurons is an alternative readjustment movement performed when intromission becomes difficult to achieve. Our findings reveal programmed transdifferentiation as a developmental mechanism underlying flexibility in innate behaviour.
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Affiliation(s)
- Laura Molina-García
- Department of Cell and Developmental Biology, University College LondonLondonUnited Kingdom
| | - Carla Lloret-Fernández
- Department of Cell and Developmental Biology, University College LondonLondonUnited Kingdom
| | - Steven J Cook
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of MedicineNew YorkUnited States
| | - Byunghyuk Kim
- Department of Genetics, Albert Einstein College of MedicineNew YorkUnited States
| | - Rachel C Bonnington
- Department of Cell and Developmental Biology, University College LondonLondonUnited Kingdom
| | - Michele Sammut
- Department of Cell and Developmental Biology, University College LondonLondonUnited Kingdom
| | - Jack M O'Shea
- Department of Cell and Developmental Biology, University College LondonLondonUnited Kingdom
| | - Sophie PR Gilbert
- Department of Cell and Developmental Biology, University College LondonLondonUnited Kingdom
| | - David J Elliott
- Department of Cell and Developmental Biology, University College LondonLondonUnited Kingdom
| | - David H Hall
- Department of Genetics, Albert Einstein College of MedicineNew YorkUnited States
| | - Scott W Emmons
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of MedicineNew YorkUnited States
- Department of Genetics, Albert Einstein College of MedicineNew YorkUnited States
| | - Arantza Barrios
- Department of Cell and Developmental Biology, University College LondonLondonUnited Kingdom
| | - Richard J Poole
- Department of Cell and Developmental Biology, University College LondonLondonUnited Kingdom
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22
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Yang Z, Mattingly BC, Hall DH, Ackley BD, Buechner M. Terminal web and vesicle trafficking proteins mediate nematode single-cell tubulogenesis. J Cell Biol 2020; 219:e202003152. [PMID: 32860501 PMCID: PMC7594493 DOI: 10.1083/jcb.202003152] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 06/15/2020] [Accepted: 08/03/2020] [Indexed: 11/22/2022] Open
Abstract
Single-celled tubules represent a complicated structure that forms during development, requiring extension of a narrow cytoplasm surrounding a lumen exerting osmotic pressure that can burst the luminal membrane. Genetic studies on the excretory canal cell of Caenorhabditis elegans have revealed many proteins that regulate the cytoskeleton, vesicular transport, and physiology of the narrow canals. Here, we show that βH-spectrin regulates the placement of intermediate filament proteins forming a terminal web around the lumen, and that the terminal web in turn retains a highly conserved protein (EXC-9/CRIP1) that regulates apical endosomal trafficking. EXC-1/IRG, the binding partner of EXC-9, is also localized to the apical membrane and affects apical actin placement and RAB-8-mediated vesicular transport. The results suggest that an intermediate filament protein acts in a novel pathway to direct the traffic of vesicles to locations of lengthening apical surface during single-celled tubule development.
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Affiliation(s)
- Zhe Yang
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS
| | | | - David H. Hall
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx, NY
| | - Brian D. Ackley
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS
| | - Matthew Buechner
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS
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23
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Cook SJ, Crouse CM, Yemini E, Hall DH, Emmons SW, Hobert O. The connectome of the Caenorhabditis elegans pharynx. J Comp Neurol 2020; 528:2767-2784. [PMID: 32352566 PMCID: PMC7601127 DOI: 10.1002/cne.24932] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 04/06/2020] [Accepted: 04/17/2020] [Indexed: 12/31/2022]
Abstract
Detailed anatomical maps of individual organs and entire animals have served as invaluable entry points for ensuing dissection of their evolution, development, and function. The pharynx of the nematode Caenorhabditis elegans is a simple neuromuscular organ with a self-contained, autonomously acting nervous system, composed of 20 neurons that fall into 14 anatomically distinct types. Using serial electron micrograph (EM) reconstruction, we re-evaluate here the connectome of the pharyngeal nervous system, providing a novel and more detailed view of its structure and predicted function. Contrasting the previous classification of pharyngeal neurons into distinct inter- and motor neuron classes, we provide evidence that most pharyngeal neurons are also likely sensory neurons and most, if not all, pharyngeal neurons also classify as motor neurons. Together with the extensive cross-connectivity among pharyngeal neurons, which is more widespread than previously realized, the sensory-motor characteristics of most neurons define a shallow network architecture of the pharyngeal connectome. Network analysis reveals that the patterns of neuronal connections are organized into putative computational modules that reflect the known functional domains of the pharynx. Compared with the somatic nervous system, pharyngeal neurons both physically associate with a larger fraction of their neighbors and create synapses with a greater proportion of their neighbors. We speculate that the overall architecture of the pharyngeal nervous system may be reminiscent of the architecture of ancestral, primitive nervous systems.
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Affiliation(s)
- Steven J. Cook
- Department of Biological Sciences, Columbia University, Howard Hughes Medical Institute, New York, NY 10027
| | - Charles M. Crouse
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Eviatar Yemini
- Department of Biological Sciences, Columbia University, Howard Hughes Medical Institute, New York, NY 10027
| | - David H. Hall
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Scott W. Emmons
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Oliver Hobert
- Department of Biological Sciences, Columbia University, Howard Hughes Medical Institute, New York, NY 10027
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24
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Cohen JD, Sparacio AP, Belfi AC, Forman-Rubinsky R, Hall DH, Maul-Newby H, Frand AR, Sundaram MV. A multi-layered and dynamic apical extracellular matrix shapes the vulva lumen in Caenorhabditis elegans. eLife 2020; 9:e57874. [PMID: 32975517 PMCID: PMC7544507 DOI: 10.7554/elife.57874] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 09/21/2020] [Indexed: 02/07/2023] Open
Abstract
Biological tubes must develop and maintain their proper diameter to transport materials efficiently. These tubes are molded and protected in part by apical extracellular matrices (aECMs) that line their lumens. Despite their importance, aECMs are difficult to image in vivo and therefore poorly understood. The Caenorhabditis elegans vulva has been a paradigm for understanding many aspects of organogenesis. Here we describe the vulva luminal matrix, which contains chondroitin proteoglycans, Zona Pellucida (ZP) domain proteins, and other glycoproteins and lipid transporters related to those in mammals. Confocal and transmission electron microscopy revealed, with unprecedented detail, a complex and dynamic aECM. Different matrix factors assemble on the apical surfaces of each vulva cell type, with clear distinctions seen between Ras-dependent (1°) and Notch-dependent (2°) cell types. Genetic perturbations suggest that chondroitin and other aECM factors together generate a structured scaffold that both expands and constricts lumen shape.
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Affiliation(s)
- Jennifer D Cohen
- Department of Genetics, University of Pennsylvania Perelman School of MedicinePhiladelphiaUnited States
| | - Alessandro P Sparacio
- Department of Genetics, University of Pennsylvania Perelman School of MedicinePhiladelphiaUnited States
| | - Alexandra C Belfi
- Department of Genetics, University of Pennsylvania Perelman School of MedicinePhiladelphiaUnited States
| | - Rachel Forman-Rubinsky
- Department of Genetics, University of Pennsylvania Perelman School of MedicinePhiladelphiaUnited States
| | - David H Hall
- Department of Neuroscience, Albert Einstein College of MedicineBronxUnited States
| | - Hannah Maul-Newby
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los AngelesLos AngelesUnited States
| | - Alison R Frand
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los AngelesLos AngelesUnited States
| | - Meera V Sundaram
- Department of Genetics, University of Pennsylvania Perelman School of MedicinePhiladelphiaUnited States
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25
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Zheng C, Atlas E, Lee HMT, Jao SLJ, Nguyen KCQ, Hall DH, Chalfie M. Opposing effects of an F-box protein and the HSP90 chaperone network on microtubule stability and neurite growth in Caenorhabditis elegans. Development 2020; 147:dev189886. [PMID: 32467239 PMCID: PMC7328132 DOI: 10.1242/dev.189886] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 05/04/2020] [Indexed: 01/08/2023]
Abstract
Molecular chaperones often work collaboratively with the ubiquitylation-proteasome system (UPS) to facilitate the degradation of misfolded proteins, which typically safeguards cellular differentiation and protects cells from stress. In this study, however, we report that the Hsp70/Hsp90 chaperone machinery and an F-box protein, MEC-15, have opposing effects on neuronal differentiation, and that the chaperones negatively regulate neuronal morphogenesis and functions. Using the touch receptor neurons (TRNs) of Caenorhabditis elegans, we find that mec-15(-) mutants display defects in microtubule formation, neurite growth, synaptic development and neuronal functions, and that these defects can be rescued by the loss of Hsp70/Hsp90 chaperones and co-chaperones. MEC-15 probably functions in a Skp-, Cullin- and F-box- containing complex to degrade DLK-1, which is an Hsp90 client protein stabilized by the chaperones. The abundance of DLK-1, and likely other Hsp90 substrates, is fine-tuned by the antagonism between MEC-15 and the chaperones; this antagonism regulates TRN development, as well as synaptic functions of GABAergic motor neurons. Therefore, a balance between the UPS and the chaperones tightly controls neuronal differentiation.
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Affiliation(s)
- Chaogu Zheng
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Emily Atlas
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Ho Ming Terence Lee
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
| | | | - Ken C Q Nguyen
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - David H Hall
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Martin Chalfie
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
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26
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Akella JS, Carter SP, Nguyen K, Tsiropoulou S, Moran AL, Silva M, Rizvi F, Kennedy BN, Hall DH, Barr MM, Blacque OE. Ciliary Rab28 and the BBSome negatively regulate extracellular vesicle shedding. eLife 2020; 9:e50580. [PMID: 32101165 PMCID: PMC7043889 DOI: 10.7554/elife.50580] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 02/02/2020] [Indexed: 12/15/2022] Open
Abstract
Cilia both receive and send information, the latter in the form of extracellular vesicles (EVs). EVs are nano-communication devices that influence cell, tissue, and organism behavior. Mechanisms driving ciliary EV biogenesis are almost entirely unknown. Here, we show that the ciliary G-protein Rab28, associated with human autosomal recessive cone-rod dystrophy, negatively regulates EV levels in the sensory organs of Caenorhabditis elegans in a cilia specific manner. Sequential targeting of lipidated Rab28 to periciliary and ciliary membranes is highly dependent on the BBSome and the prenyl-binding protein phosphodiesterase 6 subunit delta (PDE6D), respectively, and BBSome loss causes excessive and ectopic EV production. We also find that EV defective mutants display abnormalities in sensory compartment morphogenesis. Together, these findings reveal that Rab28 and the BBSome are key in vivo regulators of EV production at the periciliary membrane and suggest that EVs may mediate signaling between cilia and glia to shape sensory organ compartments. Our data also suggest that defects in the biogenesis of cilia-related EVs may contribute to human ciliopathies.
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Affiliation(s)
- Jyothi S Akella
- Department of Genetics and Human Genetics Institute of New Jersey, Rutgers UniversityPiscatawayUnited States
| | - Stephen P Carter
- School of Biomolecular and Biomedical Science, Conway Institute, University College DublinDublinIreland
| | - Ken Nguyen
- Center for C. elegans Anatomy, Albert Einstein College of MedicineBronxUnited States
| | - Sofia Tsiropoulou
- School of Biomolecular and Biomedical Science, Conway Institute, University College DublinDublinIreland
| | - Ailis L Moran
- School of Biomolecular and Biomedical Science, Conway Institute, University College DublinDublinIreland
| | - Malan Silva
- Department of Genetics and Human Genetics Institute of New Jersey, Rutgers UniversityPiscatawayUnited States
- Department of Biology, University of UtahSalt Lake CityUnited States
| | - Fatima Rizvi
- Department of Genetics and Human Genetics Institute of New Jersey, Rutgers UniversityPiscatawayUnited States
| | - Breandan N Kennedy
- School of Biomolecular and Biomedical Science, Conway Institute, University College DublinDublinIreland
| | - David H Hall
- Center for C. elegans Anatomy, Albert Einstein College of MedicineBronxUnited States
| | - Maureen M Barr
- Department of Genetics and Human Genetics Institute of New Jersey, Rutgers UniversityPiscatawayUnited States
| | - Oliver E Blacque
- School of Biomolecular and Biomedical Science, Conway Institute, University College DublinDublinIreland
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27
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Mutlu B, Chen HM, Gutnik S, Hall DH, Keppler-Ross S, Mango SE. Distinct functions and temporal regulation of methylated histone H3 during early embryogenesis. Development 2019; 146:dev174516. [PMID: 31540912 PMCID: PMC6803369 DOI: 10.1242/dev.174516] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 09/09/2019] [Indexed: 01/25/2023]
Abstract
During the first hours of embryogenesis, formation of higher-order heterochromatin coincides with the loss of developmental potential. Here, we examine the relationship between these two events, and we probe the processes that contribute to the timing of their onset. Mutations that disrupt histone H3 lysine 9 (H3K9) methyltransferases reveal that the methyltransferase MET-2 helps terminate developmental plasticity, through mono- and di-methylation of H3K9 (me1/me2), and promotes heterochromatin formation, through H3K9me3. Although loss of H3K9me3 perturbs formation of higher-order heterochromatin, embryos are still able to terminate plasticity, indicating that the two processes can be uncoupled. Methylated H3K9 appears gradually in developing C. elegans embryos and depends on nuclear localization of MET-2. We find that the timing of H3K9me2 and nuclear MET-2 is sensitive to rapid cell cycles, but not to zygotic genome activation or cell counting. These data reveal distinct roles for different H3K9 methylation states in the generation of heterochromatin and loss of developmental plasticity by MET-2, and identify the cell cycle as a crucial parameter of MET-2 regulation.
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Affiliation(s)
- Beste Mutlu
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Huei-Mei Chen
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Silvia Gutnik
- Biozentrum, University of Basel, 4056 Basel, Switzerland
| | - David H Hall
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | | | - Susan E Mango
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
- Biozentrum, University of Basel, 4056 Basel, Switzerland
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28
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Kamal M, Moshiri H, Magomedova L, Han D, Nguyen KCQ, Yeo M, Knox J, Bagg R, Won AM, Szlapa K, Yip CM, Cummins CL, Hall DH, Roy PJ. The marginal cells of the Caenorhabditis elegans pharynx scavenge cholesterol and other hydrophobic small molecules. Nat Commun 2019; 10:3938. [PMID: 31477732 PMCID: PMC6718421 DOI: 10.1038/s41467-019-11908-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Accepted: 08/09/2019] [Indexed: 12/24/2022] Open
Abstract
The nematode Caenorhabditis elegans is a bacterivore filter feeder. Through the contraction of the worm’s pharynx, a bacterial suspension is sucked into the pharynx’s lumen. Excess liquid is then shunted out of the buccal cavity through ancillary channels made by surrounding marginal cells. We find that many worm-bioactive small molecules (a.k.a. wactives) accumulate inside of the marginal cells as crystals or globular spheres. Through screens for mutants that resist the lethality associated with one crystallizing wactive we identify a presumptive sphingomyelin-synthesis pathway that is necessary for crystal and sphere accumulation. We find that expression of sphingomyelin synthase 5 (SMS-5) in the marginal cells is not only sufficient for wactive accumulation but is also important for absorbing exogenous cholesterol, without which C. elegans cannot develop. We conclude that sphingomyelin-rich marginal cells act as a sink to scavenge important nutrients from filtered liquid that might otherwise be shunted back into the environment. The C. elegans nematode worm is a filter-feeder and requires dietary sources of cholesterol. Here, the authors show that the C. elegans pharynx works as a filter to scavenge hydrophobic small molecules from its surrounding liquid environment.
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Affiliation(s)
- Muntasir Kamal
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada.,The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada
| | - Houtan Moshiri
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada.,The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada
| | - Lilia Magomedova
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Toronto, ON, M5S 3M2, Canada
| | - Duhyun Han
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada.,Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Ken C Q Nguyen
- Department of Neuroscience, Albert Einstein College of Medicine, New York, NY, 10461, USA
| | - May Yeo
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada.,The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada
| | - Jessica Knox
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada.,The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada
| | - Rachel Bagg
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada.,The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada
| | - Amy M Won
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada.,Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, M5S 3E1, Canada.,Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, M5S 3E1, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, M5S 3E1, Canada
| | - Karolina Szlapa
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada.,The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada
| | - Christopher M Yip
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada.,Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, M5S 3E1, Canada.,Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, M5S 3E1, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, M5S 3E1, Canada
| | - Carolyn L Cummins
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Toronto, ON, M5S 3M2, Canada
| | - David H Hall
- Department of Neuroscience, Albert Einstein College of Medicine, New York, NY, 10461, USA
| | - Peter J Roy
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada. .,The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada. .,Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, M5S 1A8, Canada.
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29
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del Castillo U, Gnazzo MM, Turpin CGS, Nguyen KCQ, Semaya E, Lam Y, de Cruz MA, Bembenek JN, Hall DH, Riggs B, Gelfand VI, Skop AR. Conserved role for Ataxin-2 in mediating endoplasmic reticulum dynamics. Traffic 2019; 20:436-447. [PMID: 30989774 PMCID: PMC6553494 DOI: 10.1111/tra.12647] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 04/04/2019] [Accepted: 04/05/2019] [Indexed: 12/17/2022]
Abstract
Ataxin-2, a conserved RNA-binding protein, is implicated in the late-onset neurodegenerative disease Spinocerebellar ataxia type-2 (SCA2). SCA2 is characterized by shrunken dendritic arbors and torpedo-like axons within the Purkinje neurons of the cerebellum. Torpedo-like axons have been described to contain displaced endoplasmic reticulum (ER) in the periphery of the cell; however, the role of Ataxin-2 in mediating ER function in SCA2 is unclear. We utilized the Caenorhabditis elegans and Drosophila homologs of Ataxin-2 (ATX-2 and DAtx2, respectively) to determine the role of Ataxin-2 in ER function and dynamics in embryos and neurons. Loss of ATX-2 and DAtx2 resulted in collapse of the ER in dividing embryonic cells and germline, and ultrastructure analysis revealed unique spherical stacks of ER in mature oocytes and fragmented and truncated ER tubules in the embryo. ATX-2 and DAtx2 reside in puncta adjacent to the ER in both C. elegans and Drosophila embryos. Lastly, depletion of DAtx2 in cultured Drosophila neurons recapitulated the shrunken dendritic arbor phenotype of SCA2. ER morphology and dynamics were severely disrupted in these neurons. Taken together, we provide evidence that Ataxin-2 plays an evolutionary conserved role in ER dynamics and morphology in C. elegans and Drosophila embryos during development and in fly neurons, suggesting a possible SCA2 disease mechanism.
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Affiliation(s)
- Urko del Castillo
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, 303 E Chicago Ave, Chicago, IL 60611
| | - Megan M. Gnazzo
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI 53706
| | - Christopher G. Sorensen Turpin
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee-Knoxville, Knoxville, Tennessee 37996
| | - Ken C. Q. Nguyen
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx New York, NY 10461
| | - Emily Semaya
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx New York, NY 10461
| | - Yuwan Lam
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Matthew A. de Cruz
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Joshua N. Bembenek
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee-Knoxville, Knoxville, Tennessee 37996
| | - David H. Hall
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx New York, NY 10461
| | - Blake Riggs
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Vladimir I. Gelfand
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, 303 E Chicago Ave, Chicago, IL 60611
| | - Ahna R. Skop
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI 53706
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30
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Akella JS, Silva M, Morsci NS, Nguyen KC, Rice WJ, Hall DH, Barr MM. Cell type-specific structural plasticity of the ciliary transition zone in C. elegans. Biol Cell 2019; 111:95-107. [PMID: 30681171 DOI: 10.1111/boc.201800042] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 11/15/2018] [Accepted: 11/18/2018] [Indexed: 12/13/2022]
Abstract
BACKGROUND INFORMATION The current consensus on cilia development posits that the ciliary transition zone (TZ) is formed via extension of nine centrosomal microtubules. In this model, TZ structure remains unchanged in microtubule number throughout the cilium life cycle. This model does not however explain structural variations of TZ structure seen in nature and could also lend itself to the misinterpretation that deviations from nine-doublet microtubule ultrastructure represent an abnormal phenotype. Thus, a better understanding of events that occur at the TZ in vivo during metazoan development is required. RESULTS To address this issue, we characterized ultrastructure of two types of sensory cilia in developing Caenorhabditis elegans. We discovered that, in cephalic male (CEM) and inner labial quadrant (IL2Q) sensory neurons, ciliary TZs are structurally plastic and remodel from one structure to another during animal development. The number of microtubule doublets forming the TZ can be increased or decreased over time, depending on cilia type. Both cases result in structural TZ intermediates different from TZ in cilia of adult animals. In CEM cilia, axonemal extension and maturation occurs concurrently with TZ structural maturation. CONCLUSIONS AND SIGNIFICANCE Our work extends the current model to include the structural plasticity of metazoan transition zone, which can be structurally delayed, maintained or remodelled in cell type-specific manner.
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Affiliation(s)
- Jyothi S Akella
- Department of Genetics and Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ, 08854, USA
| | - Malan Silva
- Department of Genetics and Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ, 08854, USA.,Department of Biology, University of Utah, Salt Lake City, UT, 84112, USA
| | | | - Ken C Nguyen
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - William J Rice
- Simons Electron Microscopy Center, New York Structural Biology Center, NY, 10027, USA
| | - David H Hall
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Maureen M Barr
- Department of Genetics and Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ, 08854, USA
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31
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Mutlu B, Chen HM, Moresco JJ, Orelo BD, Yang B, Gaspar JM, Keppler-Ross S, Yates JR, Hall DH, Maine EM, Mango SE. Regulated nuclear accumulation of a histone methyltransferase times the onset of heterochromatin formation in C. elegans embryos. Sci Adv 2018; 4:eaat6224. [PMID: 30140741 PMCID: PMC6105299 DOI: 10.1126/sciadv.aat6224] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Accepted: 07/18/2018] [Indexed: 05/19/2023]
Abstract
Heterochromatin formation during early embryogenesis is timed precisely, but how this process is regulated remains elusive. We report the discovery of a histone methyltransferase complex whose nuclear accumulation and activation establish the onset of heterochromatin formation in Caenorhabditis elegans embryos. We find that the inception of heterochromatin generation coincides with the accumulation of the histone H3 lysine 9 (H3K9) methyltransferase MET-2 (SETDB) into nuclear hubs. The absence of MET-2 results in delayed and disturbed heterochromatin formation, whereas accelerated nuclear localization of the methyltransferase leads to precocious H3K9 methylation. We identify two factors that bind to and function with MET-2: LIN-65, which resembles activating transcription factor 7-interacting protein (ATF7IP) and localizes MET-2 into nuclear hubs, and ARLE-14, which is orthologous to adenosine 5'-diphosphate-ribosylation factor-like 14 effector protein (ARL14EP) and promotes stable association of MET-2 with chromatin. These data reveal that nuclear accumulation of MET-2 in conjunction with LIN-65 and ARLE-14 regulates timing of heterochromatin domains during embryogenesis.
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Affiliation(s)
- Beste Mutlu
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Huei-Mei Chen
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - James J. Moresco
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, San Diego, CA 92037, USA
| | - Barbara D. Orelo
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, San Diego, CA 92037, USA
| | - Bing Yang
- Department of Biology, Syracuse University, Syracuse, NY 13244, USA
| | - John M. Gaspar
- Informatics Group, Faculty of Arts and Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Sabine Keppler-Ross
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - John R. Yates
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, San Diego, CA 92037, USA
| | - David H. Hall
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Eleanor M. Maine
- Department of Biology, Syracuse University, Syracuse, NY 13244, USA
| | - Susan E. Mango
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
- Corresponding author.
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32
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Gibson CL, Balbona JT, Niedzwiecki A, Rodriguez P, Nguyen KCQ, Hall DH, Blakely RD. Glial loss of the metallo β-lactamase domain containing protein, SWIP-10, induces age- and glutamate-signaling dependent, dopamine neuron degeneration. PLoS Genet 2018; 14:e1007269. [PMID: 29590100 PMCID: PMC5891035 DOI: 10.1371/journal.pgen.1007269] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 04/09/2018] [Accepted: 02/22/2018] [Indexed: 12/24/2022] Open
Abstract
Across phylogeny, glutamate (Glu) signaling plays a critical role in regulating neural excitability, thus supporting many complex behaviors. Perturbed synaptic and extrasynaptic Glu homeostasis in the human brain has been implicated in multiple neuropsychiatric and neurodegenerative disorders including Parkinson's disease, where theories suggest that excitotoxic insults may accelerate a naturally occurring process of dopamine (DA) neuron degeneration. In C. elegans, mutation of the glial expressed gene, swip-10, results in Glu-dependent DA neuron hyperexcitation that leads to elevated DA release, triggering DA signaling-dependent motor paralysis. Here, we demonstrate that swip-10 mutations induce premature and progressive DA neuron degeneration, with light and electron microscopy studies demonstrating the presence of dystrophic dendritic processes, as well as shrunken and/or missing cell soma. As with paralysis, DA neuron degeneration in swip-10 mutants is rescued by glial-specific, but not DA neuron-specific expression of wildtype swip-10, consistent with a cell non-autonomous mechanism. Genetic studies implicate the vesicular Glu transporter VGLU-3 and the cystine/Glu exchanger homolog AAT-1 as potential sources of Glu signaling supporting DA neuron degeneration. Degeneration can be significantly suppressed by mutations in the Ca2+ permeable Glu receptors, nmr-2 and glr-1, in genes that support intracellular Ca2+ signaling and Ca2+-dependent proteolysis, as well as genes involved in apoptotic cell death. Our studies suggest that Glu stimulation of nematode DA neurons in early larval stages, without the protective actions of SWIP-10, contributes to insults that ultimately drive DA neuron degeneration. The swip-10 model may provide an efficient platform for the identification of molecular mechanisms that enhance risk for Parkinson's disease and/or the identification of agents that can limit neurodegenerative disease progression.
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Affiliation(s)
- Chelsea L. Gibson
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States of America
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, United States of America
| | - Joseph T. Balbona
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States of America
| | - Ashlin Niedzwiecki
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States of America
| | - Peter Rodriguez
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, United States of America
| | - Ken C. Q. Nguyen
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, United States of America
| | - David H. Hall
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, United States of America
| | - Randy D. Blakely
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States of America
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, United States of America
- Department of Psychiatry, Vanderbilt University, Nashville, TN, United States of America
- The Brain Institute, Florida Atlantic University, Jupiter, FL, United States of America
- * E-mail:
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Clark JF, Meade M, Ranepura G, Hall DH, Savage-Dunn C. Caenorhabditis elegans DBL-1/BMP Regulates Lipid Accumulation via Interaction with Insulin Signaling. G3 (Bethesda) 2018; 8:343-351. [PMID: 29162682 PMCID: PMC5765361 DOI: 10.1534/g3.117.300416] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 11/18/2017] [Indexed: 11/23/2022]
Abstract
Metabolic homeostasis is coordinately controlled by diverse inputs. Understanding these regulatory networks is vital to combating metabolic disorders. The nematode Caenorhabditis elegans has emerged as a powerful, genetically tractable model system for the discovery of lipid regulatory mechanisms. Here we introduce DBL-1, the C. elegans homolog of bone morphogenetic protein 2/4 (BMP2/4), as a significant regulator of lipid homeostasis. We used neutral lipid staining and a lipid droplet marker to demonstrate that both increases and decreases in DBL-1/BMP signaling result in reduced lipid stores and lipid droplet count. We find that lipid droplet size, however, correlates positively with the level of DBL-1/BMP signaling. Regulation of lipid accumulation in the intestine occurs through non-cell-autonomous signaling, since expression of SMA-3, a Smad signal transducer, in the epidermis (hypodermis) is sufficient to rescue the loss of lipid accumulation. Finally, genetic evidence indicates that DBL-1/BMP functions upstream of Insulin/IGF-1 Signaling in lipid metabolism. We conclude that BMP signaling regulates lipid metabolism in C. elegans through interorgan signaling to the Insulin pathway, shedding light on a less well-studied regulatory mechanism for metabolic homeostasis.
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Affiliation(s)
- James F Clark
- Ph.D. Program in Biology, The Graduate Center, City University of New York (CUNY), New York, New York 10016
- Biology Department, Queens College, CUNY, Flushing, New York 11367
| | - Michael Meade
- Biology Department, Queens College, CUNY, Flushing, New York 11367
| | - Gehan Ranepura
- Biology Department, Queens College, CUNY, Flushing, New York 11367
| | - David H Hall
- Department of Neuroscience, Albert Einstein College of Medicine, New York, New York 10461
| | - Cathy Savage-Dunn
- Ph.D. Program in Biology, The Graduate Center, City University of New York (CUNY), New York, New York 10016
- Biology Department, Queens College, CUNY, Flushing, New York 11367
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Affiliation(s)
- Hiroshi Qadota
- Department of Pathology; Emory University; Atlanta Georgia 30322
| | - Yohei Matsunaga
- Department of Pathology; Emory University; Atlanta Georgia 30322
| | - Ken C.Q. Nguyen
- Department of Neuroscience; Albert Einstein College of Medicine; Bronx New York 10461
| | - Alexa Mattheyses
- Department of Cell Biology; Emory University; Atlanta Georgia 30322
| | - David H. Hall
- Department of Neuroscience; Albert Einstein College of Medicine; Bronx New York 10461
| | - Guy M. Benian
- Department of Pathology; Emory University; Atlanta Georgia 30322
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O'Hagan R, Silva M, Nguyen KCQ, Zhang W, Bellotti S, Ramadan YH, Hall DH, Barr MM. Glutamylation Regulates Transport, Specializes Function, and Sculpts the Structure of Cilia. Curr Biol 2017; 27:3430-3441.e6. [PMID: 29129530 DOI: 10.1016/j.cub.2017.09.066] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 08/09/2017] [Accepted: 09/29/2017] [Indexed: 12/16/2022]
Abstract
Ciliary microtubules (MTs) are extensively decorated with post-translational modifications (PTMs), such as glutamylation of tubulin tails. PTMs and tubulin isotype diversity act as a "tubulin code" that regulates cytoskeletal stability and the activity of MT-associated proteins such as kinesins. We previously showed that, in C. elegans cilia, the deglutamylase CCPP-1 affects ciliary ultrastructure, localization of the TRP channel PKD-2 and the kinesin-3 KLP-6, and velocity of the kinesin-2 OSM-3/KIF17, whereas a cell-specific α-tubulin isotype regulates ciliary ultrastructure, intraflagellar transport, and ciliary functions of extracellular vesicle (EV)-releasing neurons. Here we examine the role of PTMs and the tubulin code in the ciliary specialization of EV-releasing neurons using genetics, fluorescence microscopy, kymography, electron microscopy, and sensory behavioral assays. Although the C. elegans genome encodes five tubulin tyrosine ligase-like (TTLL) glutamylases, only ttll-11 specifically regulates PKD-2 localization in EV-releasing neurons. In EV-releasing cephalic male (CEM) cilia, TTLL-11 and the deglutamylase CCPP-1 regulate remodeling of 9+0 MT doublets into 18 singlet MTs. Balanced TTLL-11 and CCPP-1 activity fine-tunes glutamylation to control the velocity of the kinesin-2 OSM-3/KIF17 and kinesin-3 KLP-6 without affecting the intraflagellar transport (IFT) kinesin-II. TTLL-11 is transported by ciliary motors. TTLL-11 and CCPP-1 are also required for the ciliary function of releasing bioactive EVs, and TTLL-11 is itself a novel EV cargo. Therefore, MT glutamylation, as part of the tubulin code, controls ciliary specialization, ciliary motor-based transport, and ciliary EV release in a living animal. We suggest that cell-specific control of MT glutamylation may be a conserved mechanism to specialize the form and function of cilia.
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Affiliation(s)
- Robert O'Hagan
- Department of Genetics, Human Genetics Institute of New Jersey, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA.
| | - Malan Silva
- Department of Genetics, Human Genetics Institute of New Jersey, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Ken C Q Nguyen
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, 1410 Pelham Parkway, Bronx, NY 10461, USA
| | - Winnie Zhang
- Department of Genetics, Human Genetics Institute of New Jersey, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Sebastian Bellotti
- Department of Genetics, Human Genetics Institute of New Jersey, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Yasmin H Ramadan
- Department of Genetics, Human Genetics Institute of New Jersey, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - David H Hall
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, 1410 Pelham Parkway, Bronx, NY 10461, USA
| | - Maureen M Barr
- Department of Genetics, Human Genetics Institute of New Jersey, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
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Goupil E, Amini R, Hall DH, Labbé JC. Actomyosin contractility regulators stabilize the cytoplasmic bridge between the two primordial germ cells during Caenorhabditis elegans embryogenesis. Mol Biol Cell 2017; 28:3789-3800. [PMID: 29074566 PMCID: PMC5739295 DOI: 10.1091/mbc.e17-08-0502] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 10/18/2017] [Accepted: 10/20/2017] [Indexed: 01/08/2023] Open
Abstract
The Caenorhabditis elegans germline is syncytial but its formation is not completely understood. During embryogenesis, the germline precursor blastomere does not complete cytokinesis and maintains a stable cytoplasmic bridge between the two primordial germ cells that is enriched in actomyosin contractility regulators. Stable cytoplasmic bridges arise from failed cytokinesis, the last step of cell division, and are a key feature of syncytial architectures in the germline of most metazoans. Whereas the Caenorhabditis elegans germline is syncytial, its formation remains poorly understood. We found that the germline precursor blastomere, P4, fails cytokinesis, leaving a stable cytoplasmic bridge between the two daughter cells, Z2 and Z3. Depletion of several regulators of actomyosin contractility resulted in a regression of the membrane partition between Z2 and Z3, indicating that they are required to stabilize the cytoplasmic bridge. Epistatic analysis revealed a pathway in which Rho regulators promote accumulation of the noncannonical anillin ANI-2 at the stable cytoplasmic bridge, which in turns promotes the accumulation of the nonmuscle myosin II NMY-2 and the midbody component CYK-7 at the bridge, in part by limiting the accumulation of canonical anillin ANI-1. Our results uncover key steps in C. elegans germline formation and define a set of conserved regulators that are enriched at the primordial germ cell cytoplasmic bridge to ensure its stability during embryonic development.
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Affiliation(s)
| | - Rana Amini
- Institute of Research in Immunology and Cancer and
| | - David H Hall
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Jean-Claude Labbé
- Institute of Research in Immunology and Cancer and .,Department of Pathology and Cell Biology, Université de Montréal, Montréal, QC H3C 3J7, Canada
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Qadota H, Matsunaga Y, Nguyen KCQ, Mattheyses A, Hall DH, Benian GM. High-resolution imaging of muscle attachment structures in Caenorhabditis elegans. Cytoskeleton (Hoboken) 2017; 74:426-442. [PMID: 28921913 DOI: 10.1002/cm.21410] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Revised: 08/18/2017] [Accepted: 09/13/2017] [Indexed: 01/01/2023]
Abstract
We used structured illumination microscopy (SIM) to obtain super-resolution images of muscle attachment structures in Caenorhabditis elegans striated muscle. SIM imaging of M-line components revealed two patterns: PAT-3 (β-integrin) and proteins that interact in a complex with the cytoplasmic tail of β-integrin and localize to the basal muscle cell membrane [UNC-112 (kindlin), PAT-4 (ILK), UNC-97 (PINCH), PAT-6 (α-parvin), and UNC-95], are found in discrete, angled segments with gaps. In contrast, proteins localized throughout the depth of the M-line (UNC-89 (obscurin) and UNC-98) are imaged as continuous lines. Systematic immunostaining of muscle cell boundaries revealed that dense body components close to the basal muscle cell membrane also localize at cell boundaries. SIM imaging of muscle cell boundaries reveal "zipper-like" structures. Electron micrographs reveal electron dense material similar in appearance to dense bodies located adjacent to the basolateral cell membranes of adjacent muscle cells separated by ECM. Moreover, by EM, there are a variety of features of the muscle cell boundaries that help explain the zipper-like pattern of muscle protein localization observed by SIM. Short dense bodies in atn-1 mutants that are null for α-actinin and lack the deeper extensions of dense bodies, showed "zipper-like" structures by SIM similar to cell boundary structures, further indicating that the surface-proximal components of dense bodies form the "zipper-like" structures at cell boundaries. Moreover, mutants in thin and thick filament components do not have "dot-like" dense bodies, suggesting that myofilament tension is required for assembly or maintenance of proper dense body shape.
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Affiliation(s)
- Hiroshi Qadota
- Department of Pathology, Emory University, Atlanta, Georgia 30322
| | - Yohei Matsunaga
- Department of Pathology, Emory University, Atlanta, Georgia 30322
| | - Ken C Q Nguyen
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Alexa Mattheyses
- Department of Cell Biology, Emory University, Atlanta, Georgia 30322
| | - David H Hall
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Guy M Benian
- Department of Pathology, Emory University, Atlanta, Georgia 30322
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Boateng R, Nguyen KCQ, Hall DH, Golden A, Allen AK. Novel functions for the RNA-binding protein ETR-1 in Caenorhabditis elegans reproduction and engulfment of germline apoptotic cell corpses. Dev Biol 2017; 429:306-320. [PMID: 28648844 PMCID: PMC5603194 DOI: 10.1016/j.ydbio.2017.06.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 06/01/2017] [Accepted: 06/08/2017] [Indexed: 01/31/2023]
Abstract
RNA-binding proteins (RBPs) are essential regulators of gene expression that act through a variety of mechanisms to ensure the proper post-transcriptional regulation of their target RNAs. RBPs in multiple species have been identified as playing crucial roles during development and as having important functions in various adult organ systems, including the heart, nervous, muscle, and reproductive systems. ETR-1, a highly conserved ELAV-Type RNA-binding protein belonging to the CELF/Bruno protein family, has been previously reported to be involved in C. elegans muscle development. Animals depleted of ETR-1 have been previously characterized as arresting at the two-fold stage of embryogenesis. In this study, we show that ETR-1 is expressed in the hermaphrodite somatic gonad and germ line, and that reduction of ETR-1 via RNA interference (RNAi) results in reduced hermaphrodite fecundity. Detailed characterization of this fertility defect indicates that ETR-1 is required in both the somatic tissue and the germ line to ensure wild-type reproductive levels. Additionally, the ability of ETR-1 depletion to suppress the published WEE-1.3-depletion infertility phenotype is dependent on ETR-1 being reduced in the soma. Within the germline of etr-1(RNAi) hermaphrodite animals, we observe a decrease in average oocyte size and an increase in the number of germline apoptotic cell corpses as evident by an increased number of CED-1::GFP and acridine orange positive apoptotic germ cells. Transmission Electron Microscopy (TEM) studies confirm the significant increase in apoptotic cells in ETR-1-depleted animals, and reveal a failure of the somatic gonadal sheath cells to properly engulf dying germ cells in etr-1(RNAi) animals. Through investigation of an established engulfment pathway in C. elegans, we demonstrate that co-depletion of CED-1 and ETR-1 suppresses both the reduced fecundity and the increase in the number of apoptotic cell corpses observed in etr-1(RNAi) animals. Combined, this data identifies a novel role for ETR-1 in hermaphrodite gametogenesis and in the process of engulfment of germline apoptotic cell corpses.
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Affiliation(s)
- Ruby Boateng
- Department of Biology, Howard University, Washington, DC 20059, USA
| | - Ken C Q Nguyen
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - David H Hall
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Andy Golden
- National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Anna K Allen
- Department of Biology, Howard University, Washington, DC 20059, USA
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Zheng C, Diaz-Cuadros M, Nguyen KCQ, Hall DH, Chalfie M. Distinct effects of tubulin isotype mutations on neurite growth in Caenorhabditis elegans. Mol Biol Cell 2017; 28:2786-2801. [PMID: 28835377 PMCID: PMC5638583 DOI: 10.1091/mbc.e17-06-0424] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 08/15/2017] [Accepted: 08/16/2017] [Indexed: 12/20/2022] Open
Abstract
Different tubulin isotypes perform different functions in the regulation of microtubule (MT) structure and neurite growth, and missense mutations of tubulin genes have three types of distinct effects on MT stability and neurite growth. One α-tubulin isotype appears to induce relative instability due to the lack of potential posttranslational modification sites. Tubulins, the building block of microtubules (MTs), play a critical role in both supporting and regulating neurite growth. Eukaryotic genomes contain multiple tubulin isotypes, and their missense mutations cause a range of neurodevelopmental defects. Using the Caenorhabditis elegans touch receptor neurons, we analyzed the effects of 67 tubulin missense mutations on neurite growth. Three types of mutations emerged: 1) loss-of-function mutations, which cause mild defects in neurite growth; 2) antimorphic mutations, which map to the GTP binding site and intradimer and interdimer interfaces, significantly reduce MT stability, and cause severe neurite growth defects; and 3) neomorphic mutations, which map to the exterior surface, increase MT stability, and cause ectopic neurite growth. Structure-function analysis reveals a causal relationship between tubulin structure and MT stability. This stability affects neuronal morphogenesis. As part of this analysis, we engineered several disease-associated human tubulin mutations into C. elegans genes and examined their impact on neuronal development at the cellular level. We also discovered an α-tubulin (TBA-7) that appears to destabilize MTs. Loss of TBA-7 led to the formation of hyperstable MTs and the generation of ectopic neurites; the lack of potential sites for polyamination and polyglutamination on TBA-7 may be responsible for this destabilization.
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Affiliation(s)
- Chaogu Zheng
- Department of Biological Sciences, Columbia University, New York, NY 10027
| | | | - Ken C Q Nguyen
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461
| | - David H Hall
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Martin Chalfie
- Department of Biological Sciences, Columbia University, New York, NY 10027
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Abstract
The nematode Caenorhabditis elegans utilizes gap junctions in different fashions in virtually all of its cells. This model animal has a surprisingly large number of innexin genes within its genome, and many nematode cell types can express multiple innexins at once, leading to the formation of diverse junction types and enough redundancy to limit the effect of single gene knockdowns on animal development or behavioral phenotypes. Here, we review the general properties of these junctions, their expression patterns, and their known roles in tissue development and in the animal's connectome. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 587-596, 2017.
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Affiliation(s)
- David H Hall
- Department of Neuroscience, Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx, New York, 10461
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Silva M, Morsci N, Nguyen KCQ, Rizvi A, Rongo C, Hall DH, Barr MM. Cell-Specific α-Tubulin Isotype Regulates Ciliary Microtubule Ultrastructure, Intraflagellar Transport, and Extracellular Vesicle Biology. Curr Biol 2017; 27:968-980. [PMID: 28318980 PMCID: PMC5688951 DOI: 10.1016/j.cub.2017.02.039] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 02/13/2017] [Accepted: 02/16/2017] [Indexed: 11/22/2022]
Abstract
Cilia are found on most non-dividing cells in the human body and, when faulty, cause a wide range of pathologies called ciliopathies. Ciliary specialization in form and function is observed throughout the animal kingdom, yet mechanisms generating ciliary diversity are poorly understood. The "tubulin code"-a combination of tubulin isotypes and tubulin post-translational modifications-can generate microtubule diversity. Using C. elegans, we show that α-tubulin isotype TBA-6 sculpts 18 A- and B-tubule singlets from nine ciliary A-B doublet microtubules in cephalic male (CEM) neurons. In CEM cilia, tba-6 regulates velocities and cargoes of intraflagellar transport (IFT) kinesin-2 motors kinesin-II and OSM-3/KIF17 without affecting kinesin-3 KLP-6 motility. In addition to their unique ultrastructure and accessory kinesin-3 motor, CEM cilia are specialized to produce extracellular vesicles. tba-6 also influences several aspects of extracellular vesicle biology, including cargo sorting, release, and bioactivity. We conclude that this cell-specific α-tubulin isotype dictates the hallmarks of CEM cilia specialization. These findings provide insight into mechanisms generating ciliary diversity and lay a foundation for further understanding the tubulin code.
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Affiliation(s)
- Malan Silva
- Department of Genetics and Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ 08854, USA; Waksman Institute for Microbiology, Rutgers University, Piscataway, NJ 08854, USA
| | - Natalia Morsci
- Waksman Institute for Microbiology, Rutgers University, Piscataway, NJ 08854, USA
| | - Ken C Q Nguyen
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Anza Rizvi
- Department of Genetics and Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ 08854, USA
| | - Christopher Rongo
- Department of Genetics and Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ 08854, USA; Waksman Institute for Microbiology, Rutgers University, Piscataway, NJ 08854, USA
| | - David H Hall
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Maureen M Barr
- Department of Genetics and Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ 08854, USA; Waksman Institute for Microbiology, Rutgers University, Piscataway, NJ 08854, USA.
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Herndon LA, Wolkow CA, Driscoll M, Hall DH. Effects of Ageing on the Basic Biology and Anatomy of C. elegans. Healthy Ageing and Longevity 2017. [DOI: 10.1007/978-3-319-44703-2_2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Riddle MR, Spickard EA, Jevince A, Nguyen KCQ, Hall DH, Joshi PM, Rothman JH. Transorganogenesis and transdifferentiation in C. elegans are dependent on differentiated cell identity. Dev Biol 2016; 420:136-147. [PMID: 27717645 PMCID: PMC5224929 DOI: 10.1016/j.ydbio.2016.09.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 09/12/2016] [Accepted: 09/23/2016] [Indexed: 10/25/2022]
Abstract
The differentiated cell identities and structure of fully formed organs are generally stable after their development. In contrast, we report here that development of the C. elegans proximal somatic gonad (hermaphrodite uterus and spermathecae, and male vas deferens) can be redirected into intestine-like organs by brief expression of the ELT-7 GATA transcription factor. This process converts one developing organ into another and can hence be considered "transorganogenesis." We show that, following pulsed ELT-7 expression, cells of the uterus activate and maintain intestine-specific gene expression and are transformed at the ultrastructural level to form an epithelial tube resembling the normal intestine formed during embryogenesis. Ubiquitous ELT-7 expression activates intestinal markers in many different cell types but only cells in the somatic gonad and pharynx appear to become fully reprogrammed. We found that ectopic expression of other endoderm-promoting transcription factors, but not muscle- or ectoderm- promoting transcription factors, redirects the fate of these organs, suggesting that pharyngeal and somatic gonad cells are specifically competent to adopt intestine identity. Although the intestine, pharynx, and somatic gonad are derived from distant cell lineages, they all express the PHA-4/FoxA transcription factor. While we found that post-embryonic PHA-4 is not necessary for pharynx or uterus reprogramming and PHA-4 is not sufficient in combination with ELT-7 to induce reprogramming in other cells types, knock down of PHA-4 during embryogenesis, which abolishes normal pharynx differentiation, prevents pharyngeal precursors from being reprogrammed into intestine. These results suggest that differentiated cell identity determines susceptibility to transdifferentiation and highlight the importance of cellular context in controlling competency for reprogramming.
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Affiliation(s)
- Misty R Riddle
- Department of Molecular, Cellular, and Developmental Biology, and Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA
| | - Erik A Spickard
- Department of Molecular, Cellular, and Developmental Biology, and Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA
| | - Angela Jevince
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ken C Q Nguyen
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - David H Hall
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Pradeep M Joshi
- Department of Molecular, Cellular, and Developmental Biology, and Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA
| | - Joel H Rothman
- Department of Molecular, Cellular, and Developmental Biology, and Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA; School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
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Gleason AM, Nguyen KCQ, Hall DH, Grant BD. Syndapin/SDPN-1 is required for endocytic recycling and endosomal actin association in the C. elegans intestine. Mol Biol Cell 2016; 27:mbc.E16-02-0116. [PMID: 27630264 PMCID: PMC5170557 DOI: 10.1091/mbc.e16-02-0116] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 08/18/2016] [Accepted: 09/08/2016] [Indexed: 11/11/2022] Open
Abstract
Syndapin/Pascin family F-BAR domain proteins bind directly to membrane lipids and are associated with actin dynamics at the plasma membrane. Previous reports have also implicated mammalian syndapin 2 in endosome function during receptor recycling, but precise analysis of a putative recycling function for syndapin in mammalian systems is difficult because of syndapin effects on the earlier step of endocytic uptake, and potential redundancy among the three separate genes that encode mammalian syndapin isoforms. Here we analyze the endocytic transport function of the only C. elegans syndapin, SDPN-1. We find that SDPN-1 is a resident protein of the early and basolateral recycling endosomes in the C. elegans intestinal epithelium, and sdpn-1 deletion mutants display phenotypes indicating a block in basolateral recycling transport. sdpn-1 mutants accumulate abnormal endosomes positive for early endosome and recycling endosome markers that are normally separate, and such endosomes accumulate high levels of basolateral recycling cargo. Furthermore, we observed strong colocalization of endosomal SDPN-1 with the F-actin biosensor Lifeact, and found that loss of SDPN-1 greatly reduced Lifeact accumulation on early endosomes. Taken together our results provide strong evidence for an in vivo function of syndapin in endocytic recycling, and suggest that syndapin promotes transport via endosomal fission.
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Affiliation(s)
- Adenrele M Gleason
- Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ 08854
| | - Ken C Q Nguyen
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
| | - David H Hall
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Barth D Grant
- Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ 08854
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Gill HK, Cohen JD, Ayala-Figueroa J, Forman-Rubinsky R, Poggioli C, Bickard K, Parry JM, Pu P, Hall DH, Sundaram MV. Integrity of Narrow Epithelial Tubes in the C. elegans Excretory System Requires a Transient Luminal Matrix. PLoS Genet 2016; 12:e1006205. [PMID: 27482894 PMCID: PMC4970718 DOI: 10.1371/journal.pgen.1006205] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 06/28/2016] [Indexed: 02/07/2023] Open
Abstract
Most epithelial cells secrete a glycoprotein-rich apical extracellular matrix that can have diverse but still poorly understood roles in development and physiology. Zona Pellucida (ZP) domain glycoproteins are common constituents of these matrices, and their loss in humans is associated with a number of diseases. Understanding of the functions, organization and regulation of apical matrices has been hampered by difficulties in imaging them both in vivo and ex vivo. We identified the PAN-Apple, mucin and ZP domain glycoprotein LET-653 as an early and transient apical matrix component that shapes developing epithelia in C. elegans. LET-653 has modest effects on shaping of the vulva and epidermis, but is essential to prevent lumen fragmentation in the very narrow, unicellular excretory duct tube. We were able to image the transient LET-653 matrix by both live confocal imaging and transmission electron microscopy. Structure/function and fluorescence recovery after photobleaching studies revealed that LET-653 exists in two separate luminal matrix pools, a loose fibrillar matrix in the central core of the lumen, to which it binds dynamically via its PAN domains, and an apical-membrane-associated matrix, to which it binds stably via its ZP domain. The PAN domains are both necessary and sufficient to confer a cyclic pattern of duct lumen localization that precedes each molt, while the ZP domain is required for lumen integrity. Ectopic expression of full-length LET-653, but not the PAN domains alone, could expand lumen diameter in the developing gut tube, where LET-653 is not normally expressed. Together, these data support a model in which the PAN domains regulate the ability of the LET-653 ZP domain to interact with other factors at the apical membrane, and this ZP domain interaction promotes expansion and maintenance of lumen diameter. These data identify a transient apical matrix component present prior to cuticle secretion in C. elegans, demonstrate critical roles for this matrix component in supporting lumen integrity within narrow bore tubes such as those found in the mammalian microvasculature, and reveal functional importance of the evolutionarily conserved ZP domain in this tube protecting activity. Most organs in the body are made up of networks of tubes that transport fluids or gases. These tubes come in many different sizes and shapes, with some narrow capillaries being only one cell in diameter. As tubes develop and take their final shapes, they secrete various glycoproteins into their hollow interior or lumen. The functions of these luminal proteins are not well understood, but there is increasing evidence that they are important for lumen shaping and that their loss can contribute to diseases such as cardiovascular disease and chronic kidney disease. Through studies of the nematode C. elegans, we identified a luminal glycoprotein, LET-653, that is transiently expressed in multiple developing tube types but is particularly critical to maintain integrity of the narrowest, unicellular tubes. We identified protein domains that direct LET-653 to specific apical matrix compartments and mediate its oscillatory pattern of lumen localization. Furthermore, we showed that the LET-653 tube-protecting activity depends on a Zona Pellucida (ZP) domain similar to that found in the mammalian egg-coat and in many other luminal or sensory matrix proteins involved in human disease.
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Affiliation(s)
- Hasreet K. Gill
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Jennifer D. Cohen
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Jesus Ayala-Figueroa
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Rachel Forman-Rubinsky
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Corey Poggioli
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Kevin Bickard
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Jean M. Parry
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Biology, Georgian Court University, Lakewood, New Jersey, United States of America
| | - Pu Pu
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - David H. Hall
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Meera V. Sundaram
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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Grussendorf KA, Trezza CJ, Salem AT, Al-Hashimi H, Mattingly BC, Kampmeyer DE, Khan LA, Hall DH, Göbel V, Ackley BD, Buechner M. Facilitation of Endosomal Recycling by an IRG Protein Homolog Maintains Apical Tubule Structure in Caenorhabditis elegans. Genetics 2016; 203:1789-806. [PMID: 27334269 PMCID: PMC4981278 DOI: 10.1534/genetics.116.192559] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Accepted: 06/15/2016] [Indexed: 02/08/2023] Open
Abstract
Determination of luminal diameter is critical to the function of small single-celled tubes. A series of EXC proteins, including EXC-1, prevent swelling of the tubular excretory canals in Caenorhabditis elegans In this study, cloning of exc-1 reveals it to encode a homolog of mammalian IRG proteins, which play roles in immune response and autophagy and are associated with Crohn's disease. Mutants in exc-1 accumulate early endosomes, lack recycling endosomes, and exhibit abnormal apical cytoskeletal structure in regions of enlarged tubules. EXC-1 interacts genetically with two other EXC proteins that also affect endosomal trafficking. In yeast two-hybrid assays, wild-type and putative constitutively active EXC-1 binds to the LIM-domain protein EXC-9, whose homolog, cysteine-rich intestinal protein, is enriched in mammalian intestine. These results suggest a model for IRG function in forming and maintaining apical tubule structure via regulation of endosomal recycling.
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Affiliation(s)
- Kelly A Grussendorf
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045 Department of Biological Sciences, Minnesota State University, Mankato, Minnesota 56001
| | - Christopher J Trezza
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
| | - Alexander T Salem
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
| | - Hikmat Al-Hashimi
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
| | - Brendan C Mattingly
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
| | - Drew E Kampmeyer
- Department of Biological Sciences, Minnesota State University, Mankato, Minnesota 56001
| | - Liakot A Khan
- Mucosal Immunology and Biology Research Center, Developmental Biology and Genetics Core, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114
| | - David H Hall
- Department of Neuroscience, Center for Caenorhabditis elegans Anatomy, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Verena Göbel
- Mucosal Immunology and Biology Research Center, Developmental Biology and Genetics Core, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114
| | - Brian D Ackley
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
| | - Matthew Buechner
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
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Dimitriadi M, Derdowski A, Kalloo G, Maginnis MS, O'Hern P, Bliska B, Sorkaç A, Nguyen KCQ, Cook SJ, Poulogiannis G, Atwood WJ, Hall DH, Hart AC. Decreased function of survival motor neuron protein impairs endocytic pathways. Proc Natl Acad Sci U S A 2016; 113:E4377-86. [PMID: 27402754 PMCID: PMC4968725 DOI: 10.1073/pnas.1600015113] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Spinal muscular atrophy (SMA) is caused by depletion of the ubiquitously expressed survival motor neuron (SMN) protein, with 1 in 40 Caucasians being heterozygous for a disease allele. SMN is critical for the assembly of numerous ribonucleoprotein complexes, yet it is still unclear how reduced SMN levels affect motor neuron function. Here, we examined the impact of SMN depletion in Caenorhabditis elegans and found that decreased function of the SMN ortholog SMN-1 perturbed endocytic pathways at motor neuron synapses and in other tissues. Diminished SMN-1 levels caused defects in C. elegans neuromuscular function, and smn-1 genetic interactions were consistent with an endocytic defect. Changes were observed in synaptic endocytic proteins when SMN-1 levels decreased. At the ultrastructural level, defects were observed in endosomal compartments, including significantly fewer docked synaptic vesicles. Finally, endocytosis-dependent infection by JC polyomavirus (JCPyV) was reduced in human cells with decreased SMN levels. Collectively, these results demonstrate for the first time, to our knowledge, that SMN depletion causes defects in endosomal trafficking that impair synaptic function, even in the absence of motor neuron cell death.
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Affiliation(s)
- Maria Dimitriadi
- Department of Neuroscience, Brown University, Providence, RI 02912; Department of Biological and Environmental Sciences, University of Hertfordshire, Hatfield AL10 9AB, United Kingdom
| | - Aaron Derdowski
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI 02912
| | - Geetika Kalloo
- Department of Neuroscience, Brown University, Providence, RI 02912
| | - Melissa S Maginnis
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI 02912; Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME 04469
| | - Patrick O'Hern
- Department of Neuroscience, Brown University, Providence, RI 02912
| | - Bryn Bliska
- Department of Neuroscience, Brown University, Providence, RI 02912
| | - Altar Sorkaç
- Department of Neuroscience, Brown University, Providence, RI 02912
| | - Ken C Q Nguyen
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Steven J Cook
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461
| | - George Poulogiannis
- Chester Beatty Labs, The Institute of Cancer Research, London SW3 6JB, United Kingdom
| | - Walter J Atwood
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI 02912
| | - David H Hall
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Anne C Hart
- Department of Neuroscience, Brown University, Providence, RI 02912;
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Stavoe AKH, Hill SE, Hall DH, Colón-Ramos DA. KIF1A/UNC-104 Transports ATG-9 to Regulate Neurodevelopment and Autophagy at Synapses. Dev Cell 2016; 38:171-85. [PMID: 27396362 PMCID: PMC4961624 DOI: 10.1016/j.devcel.2016.06.012] [Citation(s) in RCA: 138] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 05/09/2016] [Accepted: 06/09/2016] [Indexed: 01/12/2023]
Abstract
Autophagy is a cellular degradation process important for neuronal development and survival. Neurons are highly polarized cells in which autophagosome biogenesis is spatially compartmentalized. The mechanisms and physiological importance of this spatial compartmentalization of autophagy in the neuronal development of living animals are not well understood. Here we determine that, in Caenorhabditis elegans neurons, autophagosomes form near synapses and are required for neurodevelopment. We first determine, through unbiased genetic screens and systematic genetic analyses, that autophagy is required cell autonomously for presynaptic assembly and for axon outgrowth dynamics in specific neurons. We observe autophagosome biogenesis in the axon near synapses, and this localization depends on the synaptic vesicle kinesin, KIF1A/UNC-104. KIF1A/UNC-104 coordinates localized autophagosome formation by regulating the transport of the integral membrane autophagy protein, ATG-9. Our findings indicate that autophagy is spatially regulated in neurons through the transport of ATG-9 by KIF1A/UNC-104 to regulate neurodevelopment.
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Affiliation(s)
- Andrea K H Stavoe
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Cell Biology and Neuroscience, Yale University School of Medicine, 295 Congress Avenue, BCMM 436B, New Haven, CT 06536-0812, USA
| | - Sarah E Hill
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Cell Biology and Neuroscience, Yale University School of Medicine, 295 Congress Avenue, BCMM 436B, New Haven, CT 06536-0812, USA
| | - David H Hall
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Daniel A Colón-Ramos
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Cell Biology and Neuroscience, Yale University School of Medicine, 295 Congress Avenue, BCMM 436B, New Haven, CT 06536-0812, USA; Instituto de Neurobiología, Recinto de Ciencias Médicas, Universidad de Puerto Rico, 201 Boulevard del Valle, San Juan 00901, Puerto Rico.
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Nichols ALA, Meelkop E, Linton C, Giordano-Santini R, Sullivan RK, Donato A, Nolan C, Hall DH, Xue D, Neumann B, Hilliard MA. The Apoptotic Engulfment Machinery Regulates Axonal Degeneration in C. elegans Neurons. Cell Rep 2016; 14:1673-1683. [PMID: 26876181 PMCID: PMC4821572 DOI: 10.1016/j.celrep.2016.01.050] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 12/23/2015] [Accepted: 01/13/2016] [Indexed: 01/31/2023] Open
Abstract
Axonal degeneration is a characteristic feature of neurodegenerative disease and nerve injury. Here, we characterize axonal degeneration in Caenorhabditis elegans neurons following laser-induced axotomy. We show that this process proceeds independently of the WLD(S) and Nmnat pathway and requires the axonal clearance machinery that includes the conserved transmembrane receptor CED-1/Draper, the adaptor protein CED-6, the guanine nucleotide exchange factor complex Crk/Mbc/dCed-12 (CED-2/CED-5/CED-12), and the small GTPase Rac1 (CED-10). We demonstrate that CED-1 and CED-6 function non-cell autonomously in the surrounding hypodermis, which we show acts as the engulfing tissue for the severed axon. Moreover, we establish a function in this process for CED-7, an ATP-binding cassette (ABC) transporter, and NRF-5, a lipid-binding protein, both associated with release of lipid-vesicles during apoptotic cell clearance. Thus, our results reveal the existence of a WLD(S)/Nmnat-independent axonal degeneration pathway, conservation of the axonal clearance machinery, and a function for CED-7 and NRF-5 in this process.
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Affiliation(s)
- Annika L A Nichols
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Ellen Meelkop
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Casey Linton
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Rosina Giordano-Santini
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Robert K Sullivan
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Alessandra Donato
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Cara Nolan
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - David H Hall
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ding Xue
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
| | - Brent Neumann
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Massimo A Hilliard
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia.
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50
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Morsci NS, Hall DH, Driscoll M, Sheng ZH. Age-Related Phasic Patterns of Mitochondrial Maintenance in Adult Caenorhabditis elegans Neurons. J Neurosci 2016; 36:1373-85. [PMID: 26818523 PMCID: PMC4728731 DOI: 10.1523/jneurosci.2799-15.2016] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 12/11/2015] [Accepted: 12/18/2015] [Indexed: 12/22/2022] Open
Abstract
Aging is associated with cognitive decline and increasing risk of neurodegeneration. Perturbation of mitochondrial function, dynamics, and trafficking are implicated in the pathogenesis of several age-associated neurodegenerative diseases. Despite this fundamental importance, the critical understanding of how organismal aging affects lifetime neuronal mitochondrial maintenance remains unknown, particularly in a physiologically relevant context. To address this issue, we performed a comprehensive in vivo analysis of age-associated changes in mitochondrial morphology, density, trafficking, and stress resistance in individual Caenorhabditis elegans neurons throughout adult life. Adult neurons display three distinct stages of increase, maintenance, and decrease in mitochondrial size and density during adulthood. Mitochondrial trafficking in the distal neuronal processes declines progressively with age starting from early adulthood. In contrast, long-lived daf-2 mutants exhibit delayed age-associated changes in mitochondrial morphology, constant mitochondrial density, and maintained trafficking rates during adulthood. Reduced mitochondrial load at late adulthood correlates with decreased mitochondrial resistance to oxidative stress. Revealing aging-associated changes in neuronal mitochondria in vivo is an essential precedent that will allow future elucidation of the mechanistic causes of mitochondrial aging. Thus, our study establishes the critical foundation for the future analysis of cellular pathways and genetic and pharmacological factors regulating mitochondrial maintenance in aging- and disease-relevant conditions. SIGNIFICANCE STATEMENT Using Caenorhabditis elegans as a model, we address long-standing questions: How does aging affect neuronal mitochondrial morphology, density, trafficking, and oxidative stress resistance? Are these age-related changes amenable to genetic manipulations that slow down the aging process? Our study illustrates that mitochondrial trafficking declines progressively from the first day of adulthood, whereas mitochondrial size, density, and resistance to oxidative stress undergo three distinct stages: increase in early adulthood, maintenance at high levels during mid-adulthood, and decline during late adulthood. Thus, our study characterizes mitochondrial aging profile at the level of a single neuron in its native environment and establishes the critical foundation for the future genetic and pharmacological dissection of factors that influence long-term mitochondrial maintenance in neurons.
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Affiliation(s)
- Natalia S Morsci
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892
| | - David H Hall
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461, and
| | - Monica Driscoll
- Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, New Jersey 08855
| | - Zu-Hang Sheng
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892,
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