1
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Phenotypical and genetical characterization of the Mad 1-2 allele during Drosophila wing development. Cells Dev 2021; 169:203761. [PMID: 34875394 DOI: 10.1016/j.cdev.2021.203761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 11/25/2021] [Accepted: 11/26/2021] [Indexed: 11/23/2022]
Abstract
Growth and patterning of Drosophila wing depends upon the sequential organizing activities of Hedgehog (Hh) and Decapentaplegic (Dpp) signaling pathways. The Hh signaling directly activates the expression of dpp through the transcription factor cubitus interruptus (Ci). Dpp itself functions as a long-range morphogen to promote cell proliferation and differentiation through an essential transcription factor encoded by Mad. Here we report that the Mad1-2 allele exhibits phenotypes distinct from classical Dpp pathway mutants in the developing wing. The activity of Dpp signaling is attenuated in Mad1-2 mutant cells. However, activation of Dpp signaling is found in a subset of cells surrounding homozygous Mad1-2 clones when the clones are located at the anterior compartment of wing disc. Further analysis reveals that Mad1-2 mutant cells display high level of Hh signaling activity and accumulate significant amount of Ci. Unexpectedly, whole genome resequencing identifies multiple mutations in the 3'UTR region of Pka-C1 genomic loci in the Mad1-2 stock. We provide genetic and molecular evidence that the Pka-C1 mutations carried by Mad1-2 likely underlies the observed Hh signaling defects. Therefore, the contribution of Pka-C1 mutation should be taken in consideration when analyzing Mad1-2 phenotypes. The isolation of independent Mad and Pka-C1 alleles from the Mad1-2 stock further supports our conclusions.
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2
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Li X, Fetter R, Schwabe T, Jung C, Liu L, Steller H, Gaul U. The cAMP effector PKA mediates Moody GPCR signaling in Drosophila blood-brain barrier formation and maturation. eLife 2021; 10:68275. [PMID: 34382936 PMCID: PMC8390003 DOI: 10.7554/elife.68275] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 08/11/2021] [Indexed: 01/01/2023] Open
Abstract
The blood-brain barrier (BBB) of Drosophila comprises a thin epithelial layer of subperineural glia (SPG), which ensheath the nerve cord and insulate it against the potassium-rich hemolymph by forming intercellular septate junctions (SJs). Previously, we identified a novel Gi/Go protein-coupled receptor (GPCR), Moody, as a key factor in BBB formation at the embryonic stage. However, the molecular and cellular mechanisms of Moody signaling in BBB formation and maturation remain unclear. Here, we identify cAMP-dependent protein kinase A (PKA) as a crucial antagonistic Moody effector that is required for the formation, as well as for the continued SPG growth and BBB maintenance in the larva and adult stage. We show that PKA is enriched at the basal side of the SPG cell and that this polarized activity of the Moody/PKA pathway finely tunes the enormous cell growth and BBB integrity. Moody/PKA signaling precisely regulates the actomyosin contractility, vesicle trafficking, and the proper SJ organization in a highly coordinated spatiotemporal manner. These effects are mediated in part by PKA's molecular targets MLCK and Rho1. Moreover, 3D reconstruction of SJ ultrastructure demonstrates that the continuity of individual SJ segments, and not their total length, is crucial for generating a proper paracellular seal. Based on these findings, we propose that polarized Moody/PKA signaling plays a central role in controlling the cell growth and maintaining BBB integrity during the continuous morphogenesis of the SPG secondary epithelium, which is critical to maintain tissue size and brain homeostasis during organogenesis.
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Affiliation(s)
- Xiaoling Li
- Tianjin Cancer Hospital Airport Hospital, Tianjin Medical University Cancer Institute & Hospital, Tianjin, China.,Department of Biochemistry, Gene Center, Center of Integrated Protein Science (CIPSM), University of Munich, Munich, Germany.,Rockefeller University, New York, United States
| | - Richard Fetter
- Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Tina Schwabe
- Department of Biochemistry, Gene Center, Center of Integrated Protein Science (CIPSM), University of Munich, Munich, Germany
| | - Christophe Jung
- Department of Biochemistry, Gene Center, Center of Integrated Protein Science (CIPSM), University of Munich, Munich, Germany
| | - Liren Liu
- Department of Gastrointestinal Cancer Biology, Tianjin Medical University Cancer Institute & Hospital; National Clinical Research Center for Cancer; Key Laboratory of Cancer Prevention and Therapy; Tianjin's Clinical Research Center for Cancer, Tianjin, China
| | | | - Ulrike Gaul
- Department of Biochemistry, Gene Center, Center of Integrated Protein Science (CIPSM), University of Munich, Munich, Germany.,Rockefeller University, New York, United States
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3
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A Comparative Perspective on Functionally-Related, Intracellular Calcium Channels: The Insect Ryanodine and Inositol 1,4,5-Trisphosphate Receptors. Biomolecules 2021; 11:biom11071031. [PMID: 34356655 PMCID: PMC8301844 DOI: 10.3390/biom11071031] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 07/08/2021] [Accepted: 07/10/2021] [Indexed: 02/03/2023] Open
Abstract
Calcium (Ca2+) homeostasis is vital for insect development and metabolism, and the endoplasmic reticulum (ER) is a major intracellular reservoir for Ca2+. The inositol 1,4,5- triphosphate receptor (IP3R) and ryanodine receptor (RyR) are large homotetrameric channels associated with the ER and serve as two major actors in ER-derived Ca2+ supply. Most of the knowledge on these receptors derives from mammalian systems that possess three genes for each receptor. These studies have inspired work on synonymous receptors in insects, which encode a single IP3R and RyR. In the current review, we focus on a fundamental, common question: “why do insect cells possess two Ca2+ channel receptors in the ER?”. Through a comparative approach, this review covers the discovery of RyRs and IP3Rs, examines their structures/functions, the pathways that they interact with, and their potential as target sites in pest control. Although insects RyRs and IP3Rs share structural similarities, they are phylogenetically distinct, have their own structural organization, regulatory mechanisms, and expression patterns, which explains their functional distinction. Nevertheless, both have great potential as target sites in pest control, with RyRs currently being targeted by commercial insecticide, the diamides.
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4
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Zhao K, Hong H, Zhao L, Huang S, Gao Y, Metwally E, Jiang Y, Sigrist SJ, Zhang YQ. Postsynaptic cAMP signalling regulates the antagonistic balance of Drosophila glutamate receptor subtypes. Development 2020; 147:226061. [PMID: 33234716 PMCID: PMC7758632 DOI: 10.1242/dev.191874] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 11/13/2020] [Indexed: 12/19/2022]
Abstract
The balance among different subtypes of glutamate receptors (GluRs) is crucial for synaptic function and plasticity at excitatory synapses. However, the mechanisms balancing synaptic GluR subtypes remain unclear. Herein, we show that the two subtypes of GluRs (A and B) expressed at Drosophila neuromuscular junction synapses mutually antagonize each other in terms of their relative synaptic levels and affect subsynaptic localization of each other, as shown by super-resolution microscopy. Upon temperature shift-induced neuromuscular junction plasticity, GluR subtype A increased but subtype B decreased with a timecourse of hours. Inhibition of the activity of GluR subtype A led to imbalance of GluR subtypes towards more GluRIIA. To gain a better understanding of the signalling pathways underlying the balance of GluR subtypes, we performed an RNA interference screen of candidate genes and found that postsynaptic-specific knockdown of dunce, which encodes cAMP phosphodiesterase, increased levels of GluR subtype A but decreased subtype B. Furthermore, bidirectional alterations of postsynaptic cAMP signalling resulted in the same antagonistic regulation of the two GluR subtypes. Our findings thus identify a direct role of postsynaptic cAMP signalling in control of the plasticity-related balance of GluRs. Summary: The antagonistic balance of GluR subtypes, which is associated with synaptic plasticity, is regulated by cAMP signalling in postsynaptic muscles of Drosophila NMJ synapses.
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Affiliation(s)
- Kai Zhao
- Key Laboratory for Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Huilin Hong
- Key Laboratory for Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Lu Zhao
- Key Laboratory for Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Sheng Huang
- Freie Universität Berlin, Institute for Biology/Genetics, Takustrasse 6, 14195 Berlin, Germany
| | - Ying Gao
- Key Laboratory for Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Elsayed Metwally
- Key Laboratory for Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yuqiang Jiang
- Key Laboratory for Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Stephan J Sigrist
- Freie Universität Berlin, Institute for Biology/Genetics, Takustrasse 6, 14195 Berlin, Germany.,NeuroCure, Charite, Chariteplatz 1, 10117 Berlin, Germany
| | - Yong Q Zhang
- Key Laboratory for Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
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5
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Strausfeld NJ, Wolff GH, Sayre ME. Mushroom body evolution demonstrates homology and divergence across Pancrustacea. eLife 2020; 9:e52411. [PMID: 32124731 PMCID: PMC7054004 DOI: 10.7554/elife.52411] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 02/03/2020] [Indexed: 02/06/2023] Open
Abstract
Descriptions of crustacean brains have focused mainly on three highly derived lineages of malacostracans: the reptantian infraorders represented by spiny lobsters, lobsters, and crayfish. Those descriptions advocate the view that dome- or cap-like neuropils, referred to as 'hemiellipsoid bodies,' are the ground pattern organization of centers that are comparable to insect mushroom bodies in processing olfactory information. Here we challenge the doctrine that hemiellipsoid bodies are a derived trait of crustaceans, whereas mushroom bodies are a derived trait of hexapods. We demonstrate that mushroom bodies typify lineages that arose before Reptantia and exist in Reptantia thereby indicating that the mushroom body, not the hemiellipsoid body, provides the ground pattern for both crustaceans and hexapods. We show that evolved variations of the mushroom body ground pattern are, in some lineages, defined by extreme diminution or loss and, in others, by the incorporation of mushroom body circuits into lobeless centers. Such transformations are ascribed to modifications of the columnar organization of mushroom body lobes that, as shown in Drosophila and other hexapods, contain networks essential for learning and memory.
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Affiliation(s)
- Nicholas James Strausfeld
- Department of Neuroscience, School of Mind, Brain and BehaviorUniversity of ArizonaTucsonUnited States
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6
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Minakawa T, Kanki Y, Nakamura K, Yamashita JK. Protein kinase A accelerates the rate of early stage differentiation of pluripotent stem cells. Biochem Biophys Res Commun 2020; 524:57-63. [PMID: 31980180 DOI: 10.1016/j.bbrc.2019.12.098] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 12/20/2019] [Indexed: 01/18/2023]
Abstract
In normal development, the rate of cell differentiation is tightly controlled and critical for normal development and stem cell differentiation. However, the underlying mechanisms regulating the rate of the differentiation are unknown, and manipulation of the rate of the stem cell differentiation is currently difficult. Here we show that activation of protein kinase A (PKA) accelerates the rate of mouse embryonic stem cell (ESC) differentiation through an early loss of ESC pluripotency markers and early appearance of mesodermal and other germ layer cells. The activation of PKA hastened differentiation by increasing the expression of a histone H3 lysine 9 (H3K9) dimethyltransferase, G9a protein, and the level of a negative epigenetic histone mark, H3K9 dimethylation (H3K9me2), in the promoter regions of the pluripotency markers Nanog and Oct4. These results elucidate a novel role of PKA on ESC differentiation and offer an experimental model for controlling the rate of ESC differentiation.
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Affiliation(s)
- Tomohiro Minakawa
- Department of Cell Growth and Differentiation, Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
| | - Yasuharu Kanki
- Isotope Science Center, The University of Tokyo, Tokyo, Japan
| | - Kae Nakamura
- Department of Cell Growth and Differentiation, Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
| | - Jun K Yamashita
- Department of Cell Growth and Differentiation, Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan.
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7
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Sayre ME, Strausfeld NJ. Mushroom bodies in crustaceans: Insect-like organization in the caridid shrimp Lebbeus groenlandicus. J Comp Neurol 2019; 527:2371-2387. [PMID: 30861118 DOI: 10.1002/cne.24678] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 02/27/2019] [Accepted: 02/28/2019] [Indexed: 11/11/2022]
Abstract
Paired centers in the forebrain of insects, called the mushroom bodies, have become the most investigated brain region of any invertebrate due to novel genetic strategies that relate unique morphological attributes of these centers to their functional roles in learning and memory. Mushroom bodies possessing all the morphological attributes of those in dicondylic insects have been identified in mantis shrimps, basal hoplocarid crustaceans that are sister to Eumalacostraca, the most species-rich group of Crustacea. However, unless other examples of mushroom bodies can be identified in Eumalacostraca, the possibility is that mushroom body-like centers may have undergone convergent evolution in Hoplocarida and are unique to this crustacean lineage. Here, we provide evidence that speaks against convergent evolution, describing in detail the paired mushroom bodies in the lateral protocerebrum of a decapod crustacean, Lebbeus groenlandicus, a species belonging to the infraorder Caridea, an ancient lineage of Eumalacostraca.
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Affiliation(s)
- Marcel E Sayre
- Lund Vision Group, Department of Biology, Lund University, Lund, Sweden
| | - Nicholas J Strausfeld
- Department of Neuroscience, School of Mind, Brain and Behavior, University of Arizona, Tucson, Arizona
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8
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Singh T, Lee EH, Hartman TR, Ruiz-Whalen DM, O'Reilly AM. Opposing Action of Hedgehog and Insulin Signaling Balances Proliferation and Autophagy to Determine Follicle Stem Cell Lifespan. Dev Cell 2018; 46:720-734.e6. [PMID: 30197240 PMCID: PMC6159899 DOI: 10.1016/j.devcel.2018.08.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 06/07/2018] [Accepted: 08/09/2018] [Indexed: 10/28/2022]
Abstract
Egg production declines with age in many species, a process linked with stem cell loss. Diet-dependent signaling has emerged as critical for stem cell maintenance during aging. Follicle stem cells (FSCs) in the Drosophila ovary are exquisitely responsive to diet-induced signals including Hedgehog (Hh) and insulin-IGF signaling (IIS), entering quiescence in the absence of nutrients and initiating proliferation rapidly upon feeding. Although highly proliferative FSCs generally exhibit an extended lifespan, we find that constitutive Hh signaling drives FSC loss and premature sterility despite high proliferative rates. This occurs due to Hh-mediated induction of autophagy in FSCs via a Ptc-dependent, Smo-independent mechanism. Hh-dependent autophagy increases during aging, triggering FSC loss and consequent reproductive arrest. IIS is necessary and sufficient to suppress Hh-induced autophagy, promoting a stable proliferative state. These results suggest that opposing action of diet-responsive IIS and Hh signals determine reproductive lifespan by modulating the proliferation-autophagy balance in FSCs during aging.
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Affiliation(s)
- Tanu Singh
- Department of Molecular Therapeutics, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111, USA; Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19111, USA
| | - Eric H Lee
- Department of Molecular Therapeutics, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111, USA
| | - Tiffiney R Hartman
- Department of Molecular Therapeutics, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111, USA
| | - Dara M Ruiz-Whalen
- Department of Molecular Therapeutics, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111, USA
| | - Alana M O'Reilly
- Department of Molecular Therapeutics, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111, USA.
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9
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Crittenden JR, Skoulakis EMC, Goldstein ES, Davis RL. Drosophila mef2 is essential for normal mushroom body and wing development. Biol Open 2018; 7:bio.035618. [PMID: 30115617 PMCID: PMC6176937 DOI: 10.1242/bio.035618] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
MEF2 (myocyte enhancer factor 2) transcription factors are found in the brain and muscle of insects and vertebrates and are essential for the differentiation of multiple cell types. We show that in the fruit fly Drosophila, MEF2 is essential for the formation of mushroom bodies in the embryonic brain and for the normal development of wings in the adult. In embryos mutant for mef2, there is a striking reduction in the number of mushroom body neurons and their axon bundles are not detectable. The onset of MEF2 expression in neurons of the mushroom bodies coincides with their formation in the embryo and, in larvae, expression is restricted to post-mitotic neurons. In flies with a mef2 point mutation that disrupts nuclear localization, we find that MEF2 is restricted to a subset of Kenyon cells that project to the α/β, and γ axonal lobes of the mushroom bodies, but not to those forming the α’/β’ lobes. Summary:Drosophila mef2 expression is restricted to subsets of mushroom body neurons, from the time of their differentiation to adulthood, and is essential for mushroom body formation.
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Affiliation(s)
- Jill R Crittenden
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Efthimios M C Skoulakis
- Division of Neuroscience, Biomedical Sciences Research Centre 'Alexander Fleming', Vari, 16672, Greece
| | - Elliott S Goldstein
- School of Life Science, Cellular, Molecular and Bioscience Program, Arizona State University, Tempe, AZ, 85287, USA
| | - Ronald L Davis
- Department of Neuroscience, The Scripps Research Institute Florida, Jupiter, FL 33458, USA
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10
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Campos B, Fletcher D, Piña B, Tauler R, Barata C. Differential gene transcription across the life cycle in Daphnia magna using a new all genome custom-made microarray. BMC Genomics 2018; 19:370. [PMID: 29776339 PMCID: PMC5960145 DOI: 10.1186/s12864-018-4725-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 04/25/2018] [Indexed: 11/23/2022] Open
Abstract
Background Unravelling the link between genes and environment across the life cycle is a challenging goal that requires model organisms with well-characterized life-cycles, ecological interactions in nature, tractability in the laboratory, and available genomic tools. Very few well-studied invertebrate model species meet these requirements, being the waterflea Daphnia magna one of them. Here we report a full genome transcription profiling of D. magna during its life-cycle. The study was performed using a new microarray platform designed from the complete set of gene models representing the whole transcribed genome of D. magna. Results Up to 93% of the existing 41,317 D. magna gene models showed differential transcription patterns across the developmental stages of D. magna, 59% of which were functionally annotated. Embryos showed the highest number of unique transcribed genes, mainly related to DNA, RNA, and ribosome biogenesis, likely related to cellular proliferation and morphogenesis of the several body organs. Adult females showed an enrichment of transcripts for genes involved in reproductive processes. These female-specific transcripts were essentially absent in males, whose transcriptome was enriched in specific genes of male sexual differentiation genes, like doublesex. Conclusion Our results define major characteristics of transcriptional programs involved in the life-cycle, differentiate males and females, and show that large scale gene-transcription data collected in whole animals can be used to identify genes involved in specific biological and biochemical processes. Electronic supplementary material The online version of this article (10.1186/s12864-018-4725-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Bruno Campos
- IDAEA-CSIC: Institute of Environmental Diagnosis and Water Research, CSIC, Barcelona, Spain.
| | | | - Benjamín Piña
- IDAEA-CSIC: Institute of Environmental Diagnosis and Water Research, CSIC, Barcelona, Spain
| | - Romà Tauler
- IDAEA-CSIC: Institute of Environmental Diagnosis and Water Research, CSIC, Barcelona, Spain
| | - Carlos Barata
- IDAEA-CSIC: Institute of Environmental Diagnosis and Water Research, CSIC, Barcelona, Spain
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11
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Vagnoni A, Bullock SL. A cAMP/PKA/Kinesin-1 Axis Promotes the Axonal Transport of Mitochondria in Aging Drosophila Neurons. Curr Biol 2018; 28:1265-1272.e4. [PMID: 29606421 PMCID: PMC5912900 DOI: 10.1016/j.cub.2018.02.048] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 01/10/2018] [Accepted: 02/19/2018] [Indexed: 11/15/2022]
Abstract
Mitochondria play fundamental roles within cells, including energy provision, calcium homeostasis, and the regulation of apoptosis. The transport of mitochondria by microtubule-based motors is critical for neuronal structure and function. This process allows local requirements for mitochondrial functions to be met and also facilitates recycling of these organelles [1, 2]. An age-related reduction in mitochondrial transport has been observed in neurons of mammalian and non-mammalian organisms [3, 4, 5, 6], and has been proposed to contribute to the broader decline in neuronal function that occurs during aging [3, 5, 6, 7]. However, the factors that influence mitochondrial transport in aging neurons are poorly understood. Here we provide evidence using the tractable Drosophila wing nerve system that the cyclic AMP/protein kinase A (cAMP/PKA) pathway promotes the axonal transport of mitochondria in adult neurons. The level of the catalytic subunit of PKA decreases during aging, and acute activation of the cAMP/PKA pathway in aged flies strongly stimulates mitochondrial motility. Thus, the age-related impairment of transport is reversible. The expression of many genes is increased by PKA activation in aged flies. However, our results indicate that elevated mitochondrial transport is due in part to upregulation of the heavy chain of the kinesin-1 motor, the level of which declines during aging. Our study identifies evolutionarily conserved factors that can strongly influence mitochondrial motility in aging neurons. cAMP/PKA pathway promotes mitochondrial transport in adult Drosophila wing neurons Pathway activation in aged flies suppresses age-related reduction in transport Levels of PKAc and kinesin-1 motor decline during aging Kinesin-1 upregulation is an important output of PKA activation in aged flies
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Affiliation(s)
- Alessio Vagnoni
- Division of Cell Biology, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK; Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King's College London, London SE5 9RX, UK.
| | - Simon L Bullock
- Division of Cell Biology, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK.
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12
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The PKA-C3 catalytic subunit is required in two pairs of interneurons for successful mating of Drosophila. Sci Rep 2018; 8:2458. [PMID: 29410515 PMCID: PMC5802784 DOI: 10.1038/s41598-018-20697-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 01/23/2018] [Indexed: 12/13/2022] Open
Abstract
Protein kinase A (PKA) has been shown to play a role in a plethora of cellular processes ranging from development to memory formation. Its activity is mediated by the catalytic subunits whereby many species express several paralogs. Drosophila encodes three catalytic subunits (PKA-C1–3) and whereas PKA-C1 has been well studied, the functions of the other two subunits were unknown. PKA-C3 is the orthologue of mammalian PRKX/Pkare and they are structurally more closely related to each other than to other catalytic subunits within their species. PRKX is expressed in the nervous system in mice but its function is also unknown. We now show that the loss of PKA-C3 in Drosophila causes copulation defects, though the flies are active and show no defects in other courtship behaviours. This phenotype is specifically due to the loss of PKA-C3 because PKA-C1 cannot replace PKA-C3. PKA-C3 is expressed in two pairs of interneurons that send projections to the ventro-lateral protocerebrum and the mushroom bodies and that synapse onto motor neurons in the ventral nerve cord. Rescue experiments show that expression of PKA-C3 in these interneurons is sufficient for copulation, suggesting a role in relaying information from the sensory system to motor neurons to initiate copulation.
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13
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Mapping Second Chromosome Mutations to Defined Genomic Regions in Drosophila melanogaster. G3-GENES GENOMES GENETICS 2018; 8:9-16. [PMID: 29066472 PMCID: PMC5765369 DOI: 10.1534/g3.117.300289] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hundreds of Drosophila melanogaster stocks are currently maintained at the Bloomington Drosophila Stock Center with mutations that have not been associated with sequence-defined genes. They have been preserved because they have interesting loss-of-function phenotypes. The experimental value of these mutations would be increased by tying them to specific genomic intervals so that geneticists can more easily associate them with annotated genes. Here, we report the mapping of 85 second chromosome complementation groups in the Bloomington collection to specific, small clusters of contiguous genes or individual genes in the sequenced genome. This information should prove valuable to Drosophila geneticists interested in processes associated with particular phenotypes and those searching for mutations affecting specific sequence-defined genes.
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14
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Richlitzki A, Latour P, Schwärzel M. Null EPAC mutants reveal a sequential order of versatile cAMP effects during Drosophila aversive odor learning. ACTA ACUST UNITED AC 2017; 24:210-215. [PMID: 28416632 PMCID: PMC5397686 DOI: 10.1101/lm.043646.116] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 03/10/2017] [Indexed: 11/25/2022]
Abstract
Here, we define a role of the cAMP intermediate EPAC in Drosophila aversive odor learning by means of null epac mutants. Complementation analysis revealed that EPAC acts downstream from the rutabaga adenylyl cyclase and in parallel to protein kinase A. By means of targeted knockdown and genetic rescue we identified mushroom body Kenyon cells (KCs) as a necessary and sufficient site of EPAC action. We provide mechanistic insights by analyzing acquisition dynamics and using the "performance increment" as a means to access the trial-based sequential organization of odor learning. Thereby we show that versatile cAMP-dependent mechanisms are engaged within a sequential order that correlate to individual trials of the training session.
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Affiliation(s)
- Antje Richlitzki
- Freie Universität Berlin, Biology/Neurobiology, D-14195 Berlin, Germany
| | - Philipp Latour
- Freie Universität Berlin, Biology/Neurobiology, D-14195 Berlin, Germany
| | - Martin Schwärzel
- Freie Universität Berlin, Biology/Neurobiology, D-14195 Berlin, Germany
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15
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An evolutionary conserved interaction between the Gcm transcription factor and the SF1 nuclear receptor in the female reproductive system. Sci Rep 2016; 6:37792. [PMID: 27886257 PMCID: PMC5122895 DOI: 10.1038/srep37792] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 11/01/2016] [Indexed: 01/08/2023] Open
Abstract
NR5A1 is essential for the development and for the function of steroid producing glands of the reproductive system. Moreover, its misregulation is associated with endometriosis, which is the first cause of infertility in women. Hr39, the Drosophila ortholog of NR5A1, is expressed and required in the secretory cells of the spermatheca, the female exocrine gland that ensures fertility by secreting substances that attract and capacitate the spermatozoids. We here identify a direct regulator of Hr39 in the spermatheca: the Gcm transcription factor. Furthermore, lack of Gcm prevents the production of the secretory cells and leads to female sterility in Drosophila. Hr39 regulation by Gcm seems conserved in mammals and involves the modification of the DNA methylation profile of mNr5a1. This study identifies a new molecular pathway in female reproductive system development and suggests a role for hGCM in the progression of reproductive tract diseases in humans.
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16
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Wolff GH, Strausfeld NJ. Genealogical correspondence of a forebrain centre implies an executive brain in the protostome-deuterostome bilaterian ancestor. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150055. [PMID: 26598732 DOI: 10.1098/rstb.2015.0055] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Orthologous genes involved in the formation of proteins associated with memory acquisition are similarly expressed in forebrain centres that exhibit similar cognitive properties. These proteins include cAMP-dependent protein kinase A catalytic subunit (PKA-Cα) and phosphorylated Ca(2+)/calmodulin-dependent protein kinase II (pCaMKII), both required for long-term memory formation which is enriched in rodent hippocampus and insect mushroom bodies, both implicated in allocentric memory and both possessing corresponding neuronal architectures. Antibodies against these proteins resolve forebrain centres, or their equivalents, having the same ground pattern of neuronal organization in species across five phyla. The ground pattern is defined by olfactory or chemosensory afferents supplying systems of parallel fibres of intrinsic neurons intersected by orthogonal domains of afferent and efferent arborizations with local interneurons providing feedback loops. The totality of shared characters implies a deep origin in the protostome-deuterostome bilaterian ancestor of elements of a learning and memory circuit. Proxies for such an ancestral taxon are simple extant bilaterians, particularly acoels that express PKA-Cα and pCaMKII in discrete anterior domains that can be properly referred to as brains.
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Affiliation(s)
- Gabriella H Wolff
- Department of Neuroscience, School of Mind, Brain, and Behavior, University of Arizona, Tucson, AZ 85721, USA
| | - Nicholas J Strausfeld
- Department of Neuroscience, School of Mind, Brain, and Behavior, University of Arizona, Tucson, AZ 85721, USA Center for Insect Science, University of Arizona, Tucson, AZ 85721, USA
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17
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Lee JH, Han JS, Kong J, Ji Y, Lv X, Lee J, Li P, Kim JB. Protein Kinase A Subunit Balance Regulates Lipid Metabolism in Caenorhabditis elegans and Mammalian Adipocytes. J Biol Chem 2016; 291:20315-28. [PMID: 27496951 DOI: 10.1074/jbc.m116.740464] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Indexed: 11/06/2022] Open
Abstract
Protein kinase A (PKA) is a cyclic AMP (cAMP)-dependent protein kinase composed of catalytic and regulatory subunits and involved in various physiological phenomena, including lipid metabolism. Here we demonstrated that the stoichiometric balance between catalytic and regulatory subunits is crucial for maintaining basal PKA activity and lipid homeostasis. To uncover the potential roles of each PKA subunit, Caenorhabditis elegans was used to investigate the effects of PKA subunit deficiency. In worms, suppression of PKA via RNAi resulted in severe phenotypes, including shortened life span, decreased egg laying, reduced locomotion, and altered lipid distribution. Similarly, in mammalian adipocytes, suppression of PKA regulatory subunits RIα and RIIβ via siRNAs potently stimulated PKA activity, leading to potentiated lipolysis without increasing cAMP levels. Nevertheless, insulin exerted anti-lipolytic effects and restored lipid droplet integrity by antagonizing PKA action. Together, these data implicate the importance of subunit stoichiometry as another regulatory mechanism of PKA activity and lipid metabolism.
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Affiliation(s)
- Jung Hyun Lee
- From the Department of Biological Sciences, Institute of Molecular Biology and Genetics, Seoul National University, 08862 Seoul, Korea
| | - Ji Seul Han
- From the Department of Biological Sciences, Institute of Molecular Biology and Genetics, Seoul National University, 08862 Seoul, Korea
| | - Jinuk Kong
- From the Department of Biological Sciences, Institute of Molecular Biology and Genetics, Seoul National University, 08862 Seoul, Korea
| | - Yul Ji
- From the Department of Biological Sciences, Institute of Molecular Biology and Genetics, Seoul National University, 08862 Seoul, Korea
| | - Xuchao Lv
- the MOE Key Laboratory of Bioinformatics and Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, 100084 Beijing, China and
| | - Junho Lee
- From the Department of Biological Sciences, Institute of Molecular Biology and Genetics, Seoul National University, 08862 Seoul, Korea, the Department of Biophysics and Chemical Biology, Seoul National University, Seoul 08862, Korea
| | - Peng Li
- the MOE Key Laboratory of Bioinformatics and Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, 100084 Beijing, China and
| | - Jae Bum Kim
- From the Department of Biological Sciences, Institute of Molecular Biology and Genetics, Seoul National University, 08862 Seoul, Korea,
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18
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Graves J, Markman S, Alegranti Y, Gechtler J, Johnson RI, Cagan R, Ben-Menahem D. The LH/CG receptor activates canonical signaling pathway when expressed in Drosophila. Mol Cell Endocrinol 2015; 413:145-56. [PMID: 26112185 DOI: 10.1016/j.mce.2015.06.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 05/29/2015] [Accepted: 06/18/2015] [Indexed: 01/12/2023]
Abstract
G-protein coupled receptors (GPCRs) and their ligands provide precise tissue regulation and are therefore often restricted to specific animal phyla. For example, the gonadotropins and their receptors are crucial for vertebrate reproduction but absent from invertebrates. In mammals, LHR mainly couples to the PKA signaling pathway, and CREB is the major transcription factor of this pathway. Here we present the results of expressing elements of the human gonadotropin system in Drosophila. Specifically, we generated transgenic Drosophila expressing the human LH/CG receptor (denoted as LHR), a constitutively active form of LHR, and an hCG analog. We demonstrate activation-dependent signaling by LHR to direct Drosophila phenotypes including lethality and specific midline defects; these phenotypes were due to LHR activation of PKA/CREB pathway activity. That the LHR can act in an invertebrate demonstrates the conservation of factors required for GPCR function among phylogenetically distant organisms. This novel gonadotropin model may assist the identification of new modulators of mammalian fertility by exploiting the powerful genetic and pharmacological tools available in Drosophila.
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Affiliation(s)
- Justin Graves
- Dept. of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New-York, NY, USA
| | - Svetlana Markman
- Dept. of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Yair Alegranti
- Dept. of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Jenia Gechtler
- Dept. of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Ruth I Johnson
- Dept. of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New-York, NY, USA
| | - Ross Cagan
- Dept. of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New-York, NY, USA
| | - David Ben-Menahem
- Dept. of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
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Olfactory pathway in Xibalbanus tulumensis: remipedian hemiellipsoid body as homologue of hexapod mushroom body. Cell Tissue Res 2015; 363:635-48. [PMID: 26358175 DOI: 10.1007/s00441-015-2275-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 08/04/2015] [Indexed: 01/01/2023]
Abstract
The Remipedia have been proposed to be the crustacean sister group of the Hexapoda. These blind cave animals heavily rely on their chemical sense and are thus rewarding subjects for the analysis of olfactory pathways. The evolution of these pathways as a character for arthropod phylogeny has recently received increasing attention. Here, we investigate the situation in Xibalbanus tulumensis by focal dye injections and immunolabelling of the catalytic subunit of the cAMP-dependent protein kinase (DC0), an enzyme particularly enriched in insect mushroom bodies. DC0 labelling of the hemiellipsoid body suggests its subdivision into a cap-like and a core neuropil. Immunofluorescence of the enzyme glutamic acid decarboxylase (GAD), which synthesizes γ-aminobutyric acid (GABA), has revealed a cluster of GABAergic interneurons in the hemiellipsoid body, reminiscent of the characteristic feedback neurons of the mushroom body. Thus, the hemiellipsoid body of Xibalbanus shares many of the characteristics of insect mushroom bodies. Nevertheless, the general neuroanatomy of the olfactory pathway in the Remipedia strongly corresponds to the malacostracan ground pattern. Given that the Remipedia are probably the sister group of the Hexapoda, the phylogenetic appearance of the typical neuropilar compartments in the insect mushroom body has to be assigned to the origins of the Hexapoda.
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Si-CSP9 regulates the integument and moulting process of larvae in the red imported fire ant, Solenopsis invicta. Sci Rep 2015; 5:9245. [PMID: 25784646 PMCID: PMC4363891 DOI: 10.1038/srep09245] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 02/25/2015] [Indexed: 01/18/2023] Open
Abstract
Chemosensory proteins (CSPs) have been predicted to be involved in development;
however, direct evidence for their involvement is lacking, and genetic basis is
largely unknown. To determine the function of the chemosensory protein 9
(Si-CSP9) gene in Solenopsis invicta, we used RNA interference to
silence Si-CSP9 in 3rd-instar larvae. The 3rd-instar larvae failed to shed
their cuticle after being fed Si-CSP9-directed siRNA, and expression
profiling of RNAi-treated and untreated control larvae showed that 375 genes were
differentially expressed. Pathway enrichment analysis revealed that 4 pathways
associated with larval development were significantly enriched. Blast analysis
revealed that one fatty acid amide hydrolase (FAAH) gene was up-regulated and
4 fatty acid synthase (FAT) genes and one protein kinase DC2 gene
(PKA) were down-regulated in the enriched pathways. Significantly higher
expression of these genes was found in 4th-instar larvae, and Pearson correlation
analysis of the expression patterns revealed significant relationships among
Si-CSP9, PKA, FAAH, and FAT1-4. Moreover, we confirmed that
expression levels of Si-CSP9, FAAH, and FAT1-4 were significantly
reduced and that the development of 3rd-instar larvae was halted with PKA
silencing. These results suggest that Si-CSP9 and PKA may be involved
in the network that contributes to development of 3rd-instar larvae.
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21
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Copf T. Developmental shaping of dendritic arbors in Drosophila relies on tightly regulated intra-neuronal activity of protein kinase A (PKA). Dev Biol 2014; 393:282-297. [PMID: 25017992 DOI: 10.1016/j.ydbio.2014.07.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 06/30/2014] [Accepted: 07/03/2014] [Indexed: 11/24/2022]
Abstract
Dendrites develop morphologies characterized by multiple levels of complexity that involve neuron type specific dendritic length and particular spatial distribution. How this is developmentally regulated and in particular which signaling molecules are crucial in the process is still not understood. Using Drosophila class IV dendritic arborization (da) neurons we test in vivo the effects of cell-autonomous dose-dependent changes in the activity levels of the cAMP-dependent Protein Kinase A (PKA) on the formation of complex dendritic arbors. We find that genetic manipulations of the PKA activity levels affect profoundly the arbor complexity with strongest impact on distal branches. Both decreasing and increasing PKA activity result in a reduced complexity of the arbors, as reflected in decreased dendritic length and number of branching points, suggesting an inverted U-shape response to PKA. The phenotypes are accompanied by changes in organelle distribution: Golgi outposts and early endosomes in distal dendritic branches are reduced in PKA mutants. By using Rab5 dominant negative we find that PKA interacts genetically with the early endosomal pathway. We test if the possible relationship between PKA and organelles may be the result of phosphorylation of the microtubule motor dynein components or Rab5. We find that Drosophila cytoplasmic dynein components are direct PKA phosphorylation targets in vitro, but not in vivo, thus pointing to a different putative in vivo target. Our data argue that tightly controlled dose-dependent intra-neuronal PKA activity levels are critical in determining the dendritic arbor complexity, one of the possible ways being through the regulation of organelle distribution.
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Affiliation(s)
- Tijana Copf
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, 630 W. 168th St. P&S 12-403, NY 10032, USA; Institute of Molecular Biology and Biotechnology, Nikolaou Plastira 100, P.O Box 1385, GR-70013 Heraklion, Crete, Greece.
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22
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Chen ZF, Zhang H, Wang H, Matsumura K, Wong YH, Ravasi T, Qian PY. Quantitative proteomics study of larval settlement in the Barnacle Balanus amphitrite. PLoS One 2014; 9:e88744. [PMID: 24551147 PMCID: PMC3923807 DOI: 10.1371/journal.pone.0088744] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 01/08/2014] [Indexed: 01/06/2023] Open
Abstract
Barnacles are major sessile components of the intertidal areas worldwide, and also one of the most dominant fouling organisms in fouling communities. Larval settlement has a crucial ecological effect not only on the distribution of the barnacle population but also intertidal community structures. However, the molecular mechanisms involved in the transition process from the larval to the juvenile stage remain largely unclear. In this study, we carried out comparative proteomic profiles of stage II nauplii, stage VI nauplii, cyprids, and juveniles of the barnacle Balanus amphitrite using label-free quantitative proteomics, followed by the measurement of the gene expression levels of candidate proteins. More than 700 proteins were identified at each stage; 80 were significantly up-regulated in cyprids and 95 in juveniles vs other stages. Specifically, proteins involved in energy and metabolism, the nervous system and signal transduction were significantly up-regulated in cyprids, whereas proteins involved in cytoskeletal remodeling, transcription and translation, cell proliferation and differentiation, and biomineralization were up-regulated in juveniles, consistent with changes associated with larval metamorphosis and tissue remodeling in juveniles. These findings provided molecular evidence for the morphological, physiological and biological changes that occur during the transition process from the larval to the juvenile stages in B. amphitrite.
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Affiliation(s)
- Zhang-Fan Chen
- KAUST Global Collaborative Research Program, Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Huoming Zhang
- Bioscience Core Laboratory, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
| | - Hao Wang
- KAUST Global Collaborative Research Program, Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Kiyotaka Matsumura
- KAUST Global Collaborative Research Program, Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Yue Him Wong
- KAUST Global Collaborative Research Program, Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Timothy Ravasi
- Integrative Systems Biology Lab, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
| | - Pei-Yuan Qian
- KAUST Global Collaborative Research Program, Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China
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23
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Genetic and functional studies implicate synaptic overgrowth and ring gland cAMP/PKA signaling defects in the Drosophila melanogaster neurofibromatosis-1 growth deficiency. PLoS Genet 2013; 9:e1003958. [PMID: 24278035 PMCID: PMC3836801 DOI: 10.1371/journal.pgen.1003958] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Accepted: 10/01/2013] [Indexed: 12/21/2022] Open
Abstract
Neurofibromatosis type 1 (NF1), a genetic disease that affects 1 in 3,000, is caused by loss of a large evolutionary conserved protein that serves as a GTPase Activating Protein (GAP) for Ras. Among Drosophila melanogaster Nf1 (dNf1) null mutant phenotypes, learning/memory deficits and reduced overall growth resemble human NF1 symptoms. These and other dNf1 defects are relatively insensitive to manipulations that reduce Ras signaling strength but are suppressed by increasing signaling through the 3′-5′ cyclic adenosine monophosphate (cAMP) dependent Protein Kinase A (PKA) pathway, or phenocopied by inhibiting this pathway. However, whether dNf1 affects cAMP/PKA signaling directly or indirectly remains controversial. To shed light on this issue we screened 486 1st and 2nd chromosome deficiencies that uncover >80% of annotated genes for dominant modifiers of the dNf1 pupal size defect, identifying responsible genes in crosses with mutant alleles or by tissue-specific RNA interference (RNAi) knockdown. Validating the screen, identified suppressors include the previously implicated dAlk tyrosine kinase, its activating ligand jelly belly (jeb), two other genes involved in Ras/ERK signal transduction and several involved in cAMP/PKA signaling. Novel modifiers that implicate synaptic defects in the dNf1 growth deficiency include the intersectin-related synaptic scaffold protein Dap160 and the cholecystokinin receptor-related CCKLR-17D1 drosulfakinin receptor. Providing mechanistic clues, we show that dAlk, jeb and CCKLR-17D1 are among mutants that also suppress a recently identified dNf1 neuromuscular junction (NMJ) overgrowth phenotype and that manipulations that increase cAMP/PKA signaling in adipokinetic hormone (AKH)-producing cells at the base of the neuroendocrine ring gland restore the dNf1 growth deficiency. Finally, supporting our previous contention that ALK might be a therapeutic target in NF1, we report that human ALK is expressed in cells that give rise to NF1 tumors and that NF1 regulated ALK/RAS/ERK signaling appears conserved in man. Neurofibromatosis type 1 (NF1) is a genetic disease that affects 1 in 3,000 and that is caused by loss of a protein that inactivates Ras oncoproteins. NF1 is a characteristically variable disease that predisposes patients to several symptoms, the most common of which include benign and malignant tumors, reduced growth and learning problems. We and others previously found that fruit fly mutants that lack a highly conserved dNf1 gene are reduced in size and exhibit impaired learning and memory, and that both defects appear due to abnormal Ras and cyclic-AMP (cAMP) signaling. The former was unremarkable, but how loss of dNf1 affects cAMP signaling remains poorly understood. Here we report results of a genetic screen for dominant modifiers of the dNf1 growth defect. This screen and follow-up functional studies support a model in which synaptic defects and reduced cAMP signaling in specific parts of the neuroendocrine ring gland contribute to the dNf1 growth defect. Beyond these results, we show that human ALK is expressed in cells that give rise to NF1 tumors, and that NF1 regulated ALK/RAS/ERK signaling is evolutionary conserved.
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24
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Yu FX, Zhang Y, Park HW, Jewell JL, Chen Q, Deng Y, Pan D, Taylor SS, Lai ZC, Guan KL. Protein kinase A activates the Hippo pathway to modulate cell proliferation and differentiation. Genes Dev 2013; 27:1223-32. [PMID: 23752589 DOI: 10.1101/gad.219402.113] [Citation(s) in RCA: 256] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The Hippo tumor suppressor pathway plays an important role in tissue homeostasis that ensures development of functional organs at proper size. The YAP transcription coactivator is a major effector of the Hippo pathway and is phosphorylated and inactivated by the Hippo pathway kinases Lats1/2. It has recently been shown that YAP activity is regulated by G-protein-coupled receptor signaling. Here we demonstrate that cyclic adenosine monophosphate (cAMP), a second messenger downstream from Gαs-coupled receptors, acts through protein kinase A (PKA) and Rho GTPases to stimulate Lats kinases and YAP phosphorylation. We also show that inactivation of YAP is crucial for PKA-induced adipogenesis. In addition, PKA activation in Drosophila inhibits the expression of Yorki (Yki, a YAP ortholog) target genes involved in cell proliferation and death. Taken together, our study demonstrates that Hippo-YAP is a key signaling branch of cAMP and PKA and reveals new insight into mechanisms of PKA in regulating a broad range of cellular functions.
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Affiliation(s)
- Fa-Xing Yu
- Department of Pharmacology, University of California at San Diego, La Jolla, California 92093, USA
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25
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Zhao J, Lu Y, Zhao X, Yao X, Shuai Y, Huang C, Wang L, Jeong SH, Zhong Y. Dissociation ofrugose-dependent short-term memory component from memory consolidation inDrosophila. GENES BRAIN AND BEHAVIOR 2013; 12:626-32. [DOI: 10.1111/gbb.12056] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2013] [Revised: 05/22/2013] [Accepted: 06/14/2013] [Indexed: 11/28/2022]
Affiliation(s)
- J. Zhao
- School of Life Sciences; Tsinghua University; Beijing; PR China
| | - Y. Lu
- School of Life Sciences; Tsinghua University; Beijing; PR China
| | - X. Zhao
- School of Life Sciences; Tsinghua University; Beijing; PR China
| | - X. Yao
- School of Life Sciences; Tsinghua University; Beijing; PR China
| | - Y. Shuai
- School of Life Sciences; Tsinghua University; Beijing; PR China
| | - C. Huang
- School of Life Sciences; Tsinghua University; Beijing; PR China
| | - L. Wang
- School of Life Sciences; Tsinghua University; Beijing; PR China
| | - S. H. Jeong
- School of Life Sciences; Tsinghua University; Beijing; PR China
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26
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Yu FX, Zhang Y, Park HW, Jewell JL, Chen Q, Deng Y, Pan D, Taylor SS, Lai ZC, Guan KL. Protein kinase A activates the Hippo pathway to modulate cell proliferation and differentiation. Genes Dev 2013. [PMID: 23752589 DOI: 10.1101/gad.219402.113.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The Hippo tumor suppressor pathway plays an important role in tissue homeostasis that ensures development of functional organs at proper size. The YAP transcription coactivator is a major effector of the Hippo pathway and is phosphorylated and inactivated by the Hippo pathway kinases Lats1/2. It has recently been shown that YAP activity is regulated by G-protein-coupled receptor signaling. Here we demonstrate that cyclic adenosine monophosphate (cAMP), a second messenger downstream from Gαs-coupled receptors, acts through protein kinase A (PKA) and Rho GTPases to stimulate Lats kinases and YAP phosphorylation. We also show that inactivation of YAP is crucial for PKA-induced adipogenesis. In addition, PKA activation in Drosophila inhibits the expression of Yorki (Yki, a YAP ortholog) target genes involved in cell proliferation and death. Taken together, our study demonstrates that Hippo-YAP is a key signaling branch of cAMP and PKA and reveals new insight into mechanisms of PKA in regulating a broad range of cellular functions.
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Affiliation(s)
- Fa-Xing Yu
- Department of Pharmacology, University of California at San Diego, La Jolla, California 92093, USA
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27
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Baumann O, Bauer A. Development of apical membrane organization and V-ATPase regulation in blowfly salivary glands. J Exp Biol 2013; 216:1225-34. [DOI: 10.1242/jeb.077420] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
SUMMARY
Secretory cells in blowfly salivary gland are specialized via morphological and physiological attributes in order to serve their main function, i.e. the transport of solutes at a high rate in response to a hormonal stimulus, namely serotonin (5-HT). This study examines the way that 5-HT-insensitive precursor cells differentiate into morphologically complex 5-HT-responsive secretory cells. By means of immunofluorescence microscopy, immunoblotting and measurements of the transepithelial potential changes, we show the following. (1) The apical membrane of the secretory cells becomes organized into an elaborate system of canaliculi and is folded into pleats during the last pupal day and the first day of adulthood. (2) The structural reorganization of the apical membrane is accompanied by an enrichment of actin filaments and phosphorylated ERM protein (phospho-moesin) at this membrane domain and by the deployment of the membrane-integral part of vacuolar-type H+-ATPase (V-ATPase). These findings suggest a role for phospho-moesin, a linker between actin filaments and membrane components, in apical membrane morphogenesis. (3) The assembly and activation of V-ATPase can be induced immediately after eclosion by way of 8-CPT-cAMP, a membrane-permeant cAMP analogue. (4) 5-HT, however, produces the assembly and activation of V-ATPase only in flies aged for at least 2 h after eclosion, indicating that, at eclosion, the 5-HT receptor/adenylyl cyclase/cAMP signalling pathway is inoperative upstream of cAMP. (5) 5-HT activates both the Ca2+ signalling pathway and the cAMP signalling cascade in fully differentiated secretory cells. However, the functionality of these signalling cascades does not seem to be established in a tightly coordinated manner during cell differentation.
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Affiliation(s)
- Otto Baumann
- Institut für Biochemie und Biologie, Zoophysiologie, Universität Potsdam, Karl-Liebknecht-Str. 24–25, 14476 Potsdam, Germany
| | - Alexandra Bauer
- Institut für Biochemie und Biologie, Zoophysiologie, Universität Potsdam, Karl-Liebknecht-Str. 24–25, 14476 Potsdam, Germany
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28
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Laneve P, Delaporte C, Trebuchet G, Komonyi O, Flici H, Popkova A, D'Agostino G, Taglini F, Kerekes I, Giangrande A. The Gcm/Glide molecular and cellular pathway: new actors and new lineages. Dev Biol 2012; 375:65-78. [PMID: 23276603 DOI: 10.1016/j.ydbio.2012.12.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 11/18/2012] [Accepted: 12/14/2012] [Indexed: 12/21/2022]
Abstract
In Drosophila, the transcription factor Gcm/Glide plays a key role in cell fate determination and cellular differentiation. In light of its crucial biological impact, major efforts have been put for analyzing its properties as master regulator, from both structural and functional points of view. However, the lack of efficient antibodies specific to the Gcm/Glide protein precluded thorough analyses of its regulation and activity in vivo. In order to relieve such restraints, we designed an epitope-tagging approach to "FLAG"-recognize and analyze the functional protein both in vitro (exogenous Gcm/Glide) and in vivo (endogenous protein). We here (i) reveal a tight interconnection between the small RNA and the Gcm/Glide pathways. AGO1 and miR-1 are Gcm/Glide targets whereas miR-279 negatively controls Gcm/Glide expression (ii) identify a novel cell population, peritracheal cells, expressing and requiring Gcm/Glide. Peritracheal cells are non-neuronal neurosecretory cells that are essential in ecdysis. In addition to emphasizing the importance of following the distribution and the activity of endogenous proteins in vivo, this study provides new insights and a novel frame to understand the Gcm/Glide biology.
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Affiliation(s)
- Pietro Laneve
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch 67404, France
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29
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Learning and memory deficits consequent to reduction of the fragile X mental retardation protein result from metabotropic glutamate receptor-mediated inhibition of cAMP signaling in Drosophila. J Neurosci 2012; 32:13111-24. [PMID: 22993428 DOI: 10.1523/jneurosci.1347-12.2012] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Loss of the RNA-binding fragile X protein [fragile X mental retardation protein (FMRP)] results in a spectrum of cognitive deficits, the fragile X syndrome (FXS), while aging individuals with decreased protein levels present with a subset of these symptoms and tremor. The broad range of behavioral deficits likely reflects the ubiquitous distribution and multiple functions of the protein. FMRP loss is expected to affect multiple neuronal proteins and intracellular signaling pathways, whose identity and interactions are essential in understanding and ameliorating FXS symptoms. We used heterozygous mutants and targeted RNA interference-mediated abrogation in Drosophila to uncover molecular pathways affected by FMRP reduction. We present evidence that FMRP loss results in excess metabotropic glutamate receptor (mGluR) activity, attributable at least in part to elevation of the protein in affected neurons. Using high-resolution behavioral, genetic, and biochemical analyses, we present evidence that excess mGluR upon FMRP attenuation is linked to the cAMP decrement reported in patients and models, and underlies olfactory associative learning and memory deficits. Furthermore, our data indicate positive transcriptional regulation of the fly fmr1 gene by cAMP, via protein kinase A, likely through the transcription factor CREB. Because the human Fmr1 gene also contains CREB binding sites, the interaction of mGluR excess and cAMP signaling defects we present suggests novel combinatorial pharmaceutical approaches to symptom amelioration upon FMRP attenuation.
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Brown S, Wolff G. Fine structural organization of the hemiellipsoid body of the land hermit crab, Coenobita clypeatus. J Comp Neurol 2012; 520:2847-63. [PMID: 22318704 DOI: 10.1002/cne.23058] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Electron microscopical observations of the hemiellipsoid bodies of the land hermit crab Coenobita clypeatus resolve microglomerular synaptic complexes that are comparable to those observed in the calyces of insect mushroom bodies and which characterize olfactory inputs onto intrinsic neurons. In an adult hermit crab, intrinsic neurons and one class of efferent neurons originate from neuronal somata of globuli cells covering the hemiellipsoid bodies. Counts of their nucleoli show that about 120,000 globuli cells supply each hemiellipsoid body in an adult hermit crab. This number is comparable to the number of globuli cells supplying mushroom bodies of certain insects, such as honey bees and cockroaches. Counts of axons in tracts leading from the olfactory lobes to the hemiellipsoid bodies resolve 20,000 afferent axons, however, an order of magnitude greater than known for any insect. These afferent axons provide numerous swollen varicosities, each presynaptic to many small profiles, and thus comparable to the microglomeruli that characterize insect mushroom body calyces. Also, common to mushroom bodies and hemiellipsoid bodies are arrangements of intrinsic neurons, afferent neurons containing dense core vesicles, and systems of serial synaptic complexes that relate to postsynaptic profiles of efferent neurons. Together, the ultrastructural organization of the hemiellipsoid bodies of C. clypeatus supports the proposition that this center may share a common origin with the insect mushroom body despite obvious divergent evolution of overall shape.
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Affiliation(s)
- Sheena Brown
- Department of Neuroscience, University of Arizona, Tucson, Arizona 85721, USA.
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Wolff G, Harzsch S, Hansson BS, Brown S, Strausfeld N. Neuronal organization of the hemiellipsoid body of the land hermit crab, Coenobita clypeatus: correspondence with the mushroom body ground pattern. J Comp Neurol 2012; 520:2824-46. [PMID: 22547177 DOI: 10.1002/cne.23059] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Malacostracan crustaceans and dicondylic insects possess large second-order olfactory neuropils called, respectively, hemiellipsoid bodies and mushroom bodies. Because these centers look very different in the two groups of arthropods, it has been debated whether these second-order sensory neuropils are homologous or whether they have evolved independently. Here we describe the results of neuroanatomical observations and experiments that resolve the neuronal organization of the hemiellipsoid body in the terrestrial Caribbean hermit crab, Coenobita clypeatus, and compare this organization with the mushroom body of an insect, the cockroach Periplaneta americana. Comparisons of the morphology, ultrastructure, and immunoreactivity of the hemiellipsoid body of C. clypeatus and the mushroom body of the cockroach P. americana reveal in both a layered motif provided by rectilinear arrangements of extrinsic and intrinsic neurons as well as a microglomerular organization. Furthermore, antibodies raised against DC0, the major catalytic subunit of protein kinase A, specifically label both the crustacean hemiellipsoid bodies and insect mushroom bodies. In crustaceans lacking eyestalks, where the entire brain is contained within the head, this antibody selectively labels hemiellipsoid bodies, the superior part of which approximates a mushroom body's calyx in having large numbers of microglomeruli. We propose that these multiple correspondences indicate homology of the crustacean hemiellipsoid body and insect mushroom body and discuss the implications of this with respect to the phylogenetic history of arthropods. We conclude that crustaceans, insects, and other groups of arthropods share an ancestral neuronal ground pattern that is specific to their second-order olfactory centers.
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Affiliation(s)
- Gabriella Wolff
- Department of Neuroscience, University of Arizona, Tucson, Arizona 85721, USA.
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Yamamizu K, Fujihara M, Tachibana M, Katayama S, Takahashi A, Hara E, Imai H, Shinkai Y, Yamashita JK. Protein kinase A determines timing of early differentiation through epigenetic regulation with G9a. Cell Stem Cell 2012; 10:759-770. [PMID: 22704517 DOI: 10.1016/j.stem.2012.02.022] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 01/20/2012] [Accepted: 02/24/2012] [Indexed: 12/24/2022]
Abstract
Timing of cell differentiation is strictly controlled and is crucial for normal development and stem cell differentiation. However, underlying mechanisms regulating differentiation timing are fully unknown. Here, we show a molecular mechanism determining differentiation timing from mouse embryonic stem cells (ESCs). Activation of protein kinase A (PKA) modulates differentiation timing to accelerate the appearance of mesoderm and other germ layer cells, reciprocally correlated with the earlier disappearance of pluripotent markers after ESC differentiation. PKA activation increases protein expression of G9a, an H3K9 methyltransferase, along with earlier H3K9 dimethylation and DNA methylation in Oct3/4 and Nanog gene promoters. Deletion of G9a completely abolishes PKA-elicited acceleration of differentiation and epigenetic modification. Furthermore, G9a knockout mice show prolonged expressions of Oct3/4 and Nanog at embryonic day 7.5 and delayed development. In this study, we demonstrate molecular machinery that regulates timing of multilineage differentiation by linking signaling with epigenetics.
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Affiliation(s)
- Kohei Yamamizu
- Department of Stem Cell Differentiation, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8507, Japan; Department of Cell Growth and Differentiation, Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto 606-8507, Japan
| | - Mayako Fujihara
- Laboratory of Reproductive Biology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Makoto Tachibana
- Experimental Research Center for Infectious Disease, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan
| | - Shiori Katayama
- Department of Stem Cell Differentiation, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8507, Japan; Department of Cell Growth and Differentiation, Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto 606-8507, Japan
| | - Akiko Takahashi
- Cancer Institute, Japanese Foundation for Cancer Research, Tokyo 135-8550, Japan
| | - Eiji Hara
- Cancer Institute, Japanese Foundation for Cancer Research, Tokyo 135-8550, Japan
| | - Hiroshi Imai
- Laboratory of Reproductive Biology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Yoichi Shinkai
- Experimental Research Center for Infectious Disease, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan
| | - Jun K Yamashita
- Department of Stem Cell Differentiation, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8507, Japan; Department of Cell Growth and Differentiation, Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto 606-8507, Japan.
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Böhm A, Szucsich NU, Pass G. Brain anatomy in Diplura (Hexapoda). Front Zool 2012; 9:26. [PMID: 23050723 PMCID: PMC3585824 DOI: 10.1186/1742-9994-9-26] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 10/03/2012] [Indexed: 01/27/2023] Open
Abstract
Background In the past decade neuroanatomy has proved to be a valuable source of character systems that provide insights into arthropod relationships. Since the most detailed description of dipluran brain anatomy dates back to Hanström (1940) we re-investigated the brains of Campodea augens and Catajapyx aquilonaris with modern neuroanatomical techniques. The analyses are based on antibody staining and 3D reconstruction of the major neuropils and tracts from semi-thin section series. Results Remarkable features of the investigated dipluran brains are a large central body, which is organized in nine columns and three layers, and well developed mushroom bodies with calyces receiving input from spheroidal olfactory glomeruli in the deutocerebrum. Antibody staining against a catalytic subunit of protein kinase A (DC0) was used to further characterize the mushroom bodies. The japygid Catajapyx aquilonaris possesses mushroom bodies which are connected across the midline, a unique condition within hexapods. Conclusions Mushroom body and central body structure shows a high correspondence between japygids and campodeids. Some unique features indicate that neuroanatomy further supports the monophyly of Diplura. In a broader phylogenetic context, however, the polarization of brain characters becomes ambiguous. The mushroom bodies and the central body of Diplura in several aspects resemble those of Dicondylia, suggesting homology. In contrast, Archaeognatha completely lack mushroom bodies and exhibit a central body organization reminiscent of certain malacostracan crustaceans. Several hypotheses of brain evolution at the base of the hexapod tree are discussed.
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Affiliation(s)
- Alexander Böhm
- Department of Evolutionary Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria.
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Groen CM, Spracklen AJ, Fagan TN, Tootle TL. Drosophila Fascin is a novel downstream target of prostaglandin signaling during actin remodeling. Mol Biol Cell 2012; 23:4567-78. [PMID: 23051736 PMCID: PMC3510018 DOI: 10.1091/mbc.e12-05-0417] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Prostaglandins (PGs) regulate the actin cytoskeleton. However, their mechanisms of action are unknown. Use of Drosophila oogenesis—specifically nurse cell dumping—as a model shows that PGs regulate the actin bundler Fascin to control parallel actin filament bundle formation and cortical actin integrity. Although prostaglandins (PGs)—lipid signals produced downstream of cyclooxygenase (COX) enzymes—regulate actin cytoskeletal dynamics, their mechanisms of action are unknown. We previously established Drosophila oogenesis, in particular nurse cell dumping, as a new model to determine how PGs regulate actin remodeling. PGs, and thus the Drosophila COX-like enzyme Pxt, are required for both the parallel actin filament bundle formation and the cortical actin strengthening required for dumping. Here we provide the first link between Fascin (Drosophila Singed, Sn), an actin-bundling protein, and PGs. Loss of either pxt or fascin results in similar actin defects. Fascin interacts, both pharmacologically and genetically, with PGs, as reduced Fascin levels enhance the effects of COX inhibition and synergize with reduced Pxt levels to cause both parallel bundle and cortical actin defects. Conversely, overexpression of Fascin in the germline suppresses the effects of COX inhibition and genetic loss of Pxt. These data lead to the conclusion that PGs regulate Fascin to control actin remodeling. This novel interaction has implications beyond Drosophila, as both PGs and Fascin-1, in mammalian systems, contribute to cancer cell migration and invasion.
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Affiliation(s)
- Christopher M Groen
- Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
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Heuer CM, Kollmann M, Binzer M, Schachtner J. Neuropeptides in insect mushroom bodies. ARTHROPOD STRUCTURE & DEVELOPMENT 2012; 41:199-226. [PMID: 22401884 DOI: 10.1016/j.asd.2012.02.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Revised: 02/22/2012] [Accepted: 02/23/2012] [Indexed: 05/31/2023]
Abstract
Owing to their experimental amenability, insect nervous systems continue to be in the foreground of investigations into information processing in - ostensibly - simple neuronal networks. Among the cerebral neuropil regions that hold a particular fascination for neurobiologists are the paired mushroom bodies, which, despite their function in other behavioral contexts, are most renowned for their role in learning and memory. The quest to understand the processes that underlie these capacities has been furthered by research focusing on unraveling neuroanatomical connections of the mushroom bodies and identifying key players that characterize the molecular machinery of mushroom body neurons. However, on a cellular level, communication between intrinsic and extrinsic mushroom body neurons still remains elusive. The present account aims to provide an overview on the repertoire of neuropeptides expressed in and utilized by mushroom body neurons. Existing data for a number of insect representatives is compiled and some open gaps in the record are filled by presenting additional original data.
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Affiliation(s)
- Carsten M Heuer
- Philipps-University Marburg, Department of Biology, Animal Physiology, Marburg, Germany.
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36
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Abstract
Protein kinase A (PKA) is a well-known kinase that plays fundamental roles in a variety of biological processes. In Hedgehog-responsive cells, PKA plays key roles in proliferation and fate specification by modulating the transduction of Hedgehog signaling. In the absence of Hedgehog, a basal level of PKA activity represses the transcription of Hedgehog target genes. The main substrates of PKA in this process are the Ci/Gli family of bipotential transcription factors, which activate and repress Hedgehog target gene expression. PKA phosphorylates Ci/Gli, promoting the production of the repressor forms of Ci/Gli and thus repressing Hedgehog target gene expression. In contrast, the activation of Hedgehog signaling in response to Hedgehog increases the active forms of Ci/Gli, resulting in Hedgehog target gene expression. Because both decreased and increased levels of PKA activity cause abnormal cell proliferation and alter cell fate specification, the basal level of PKA activity in Hedgehog-responsive cells should be precisely regulated. However, the mechanism by which PKA activity is regulated remains obscure and appears to vary between cell types, tissues, and organisms. To date, two mechanisms have been proposed. One is a classical mechanism in which PKA activity is regulated by a small second messenger, cAMP; the other is a novel mechanism in which PKA activity is regulated by a protein, Misty somites.
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Critical role for protein kinase A in the acquisition of gregarious behavior in the desert locust. Proc Natl Acad Sci U S A 2011; 109:E381-7. [PMID: 22184243 DOI: 10.1073/pnas.1114990109] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The mechanisms that integrate genetic and environmental information to coordinate the expression of complex phenotypes are little understood. We investigated the role of two protein kinases (PKs) in the population density-dependent transition to gregarious behavior that underlies swarm formation in desert locusts: the foraging gene product, a cGMP-dependent PK (PKG) implicated in switching between alternative group-related behaviors in several animal species; and cAMP-dependent PK (PKA), a signal transduction protein with a preeminent role in different forms of learning. Solitarious locusts acquire key behavioral characters of the swarming gregarious phase within just 1 to 4 h of forced crowding. Injecting the PKA inhibitor KT5720 before crowding prevented this transition, whereas injecting KT5823, an inhibitor of PKG, did not. Neither drug altered the behavior of long-term gregarious locusts. RNAi against foraging effectively reduced its expression in the central nervous system, but this did not prevent gregarization upon crowding. By contrast, solitarious locusts with an RNAi-induced reduction in PKA catalytic subunit C1 expression behaved less gregariously after crowding, and RNAi against the inhibitory R1 subunit promoted more extensive gregarization following a brief crowding period. A central role of PKA is congruent with the recent discovery that serotonin mediates gregarization in locusts and with findings in vertebrates that similarly implicate PKA in the capacity to cope with adverse life events. Our results show that PKA has been coopted into effecting the wide-ranging transformation from solitarious to gregarious behavior, with PKA-mediated behavioral plasticity resulting in an environmentally driven reorganization of a complex phenotype.
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Kollmann M, Huetteroth W, Schachtner J. Brain organization in Collembola (springtails). ARTHROPOD STRUCTURE & DEVELOPMENT 2011; 40:304-316. [PMID: 21420507 DOI: 10.1016/j.asd.2011.02.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Revised: 01/05/2011] [Accepted: 02/17/2011] [Indexed: 05/30/2023]
Abstract
Arthropoda is comprised of four major taxa: Hexapoda, Crustacea, Myriapoda and Chelicerata. Although this classification is widely accepted, there is still some debate about the internal relationships of these groups. In particular, the phylogenetic position of Collembola remains enigmatic. Some molecular studies place Collembola into a close relationship to Protura and Diplura within the monophyletic Hexapoda, but this placement is not universally accepted, as Collembola is also regarded as either the sister group to Branchiopoda (a crustacean taxon) or to Pancrustacea (crustaceans + hexapods). To contribute to the current debate on the phylogenetic position of Collembola, we examined the brains in three collembolan species: Folsomia candida, Protaphorura armata and Tetrodontophora bielanensis, using antennal backfills, series of semi-thin sections, and immunostaining technique with several antisera, in conjunction with confocal laser scanning microscopy and three-dimensional reconstructions. We identified several neuroanatomical structures in the collembolan brain, including a fan-shaped central body showing a columnar organization, a protocerebral bridge, one pair of antennal lobes with 20-30 spheroidal glomeruli each, and a structure, which we interpret as a simply organized mushroom body. The results of our neuroanatomical study are consistent with the phylogenetic position of Collembola within the Hexapoda and do not contradict the hypothesis of a close relationship of Collembola, Protura and Diplura.
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Affiliation(s)
- Martin Kollmann
- Department of Biology - Animal Physiology, Philipps-University Marburg, Karl-von-Frisch-Str. 8, D-35032 Marburg, Germany
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Kollmann M, Minoli S, Bonhomme J, Homberg U, Schachtner J, Tagu D, Anton S. Revisiting the anatomy of the central nervous system of a hemimetabolous model insect species: the pea aphid Acyrthosiphon pisum. Cell Tissue Res 2011; 343:343-55. [PMID: 21170552 DOI: 10.1007/s00441-010-1099-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Accepted: 11/22/2010] [Indexed: 12/01/2022]
Abstract
Aphids show a marked phenotypic plasticity, producing asexual or sexual and winged or wingless morphs depending on environmental conditions and season. We describe here the general structure of the brain of various morphs of the pea aphid Acyrthosiphon pisum. This is the first detailed anatomical study of the central nervous system of an aphid by immunocytochemistry (synapsin, serotonin, and several neuropeptides), ethyl-gallate staining, confocal laser scanning microscopy, and three-dimensional reconstructions. The study has revealed well-developed optic lobes composed of lamina, medulla, and lobula complex. Ocelli are only present in males and winged parthenogenetic females. The central complex is well-defined, with a central body divided into two parts, a protocerebral bridge, and affiliated lateral accessory lobes. The mushroom bodies are ill-defined, lacking calyces, and only being visualized by using an antiserum against the neuropeptide orcokinin. The antennal lobes contain poorly delineated glomeruli but can be clearly visualized by performing antennal backfills. On the basis of our detailed description of the brain of winged and wingless parthenogenetic A. pisum females, an anatomical map is now available that should improve our knowledge of the way that these structures are involved in the regulation of phenotypic plasticity.
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Affiliation(s)
- Martin Kollmann
- Department of Biology - Animal Physiology, Philipps University Marburg, 35043, Marburg, Germany
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Khurana JS, Theurkauf W. piRNAs, transposon silencing, and Drosophila germline development. ACTA ACUST UNITED AC 2011; 191:905-13. [PMID: 21115802 PMCID: PMC2995163 DOI: 10.1083/jcb.201006034] [Citation(s) in RCA: 134] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Transposons are prominent features of most eukaryotic genomes and mobilization of these elements triggers genetic instability. Transposon silencing is particularly critical in the germline, which maintains the heritable genetic complement. Piwi-interacting RNAs (piRNAs) have emerged as central players in transposon silencing and genome maintenance during germline development. In particular, research on Drosophila oogenesis has provided critical insights into piRNA biogenesis and transposon silencing. In this system, the ability to place piRNA mutant phenotypes within a well-defined developmental framework has been instrumental in elucidating the molecular mechanisms underlying the connection between piRNAs and transposon control.
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Affiliation(s)
- Jaspreet S Khurana
- Program in Cell and Developmental Dynamics, and Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
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41
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Zheng X, Mann RK, Sever N, Beachy PA. Genetic and biochemical definition of the Hedgehog receptor. Genes Dev 2010; 24:57-71. [PMID: 20048000 DOI: 10.1101/gad.1870310] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Although the transporter-like protein Patched (Ptc) is genetically implicated in reception of the extracellular Hedgehog (Hh) protein signal, a clear definition of the Hh receptor is complicated by the existence of additional Hh-binding proteins and, in Drosophila, by the lack of physical evidence for direct binding of Hh to Ptc. Here we show that activity of Ihog (Interference hedgehog), or of its close relative Boi (Brother of Ihog), is absolutely required for Hh biological response and for sequestration of the Hh protein to limit long-range signaling. We demonstrate that Ihog interacts directly with Ptc, is required for presentation of Ptc on the cell surface, and that Ihog and Ptc are both required for high-affinity Hh binding. On the basis of their joint roles in ligand binding, signal transduction, and receptor trafficking, we conclude that Ihog and Ptc together constitute the Drosophila Hh receptor.
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Affiliation(s)
- Xiaoyan Zheng
- Department of Developmental Biology, Institute for Stem Cell Biology and Regenerative Medicine, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California 94305, USA
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Strausfeld NJ, Sinakevitch I, Brown SM, Farris SM. Ground plan of the insect mushroom body: functional and evolutionary implications. J Comp Neurol 2009; 513:265-291. [PMID: 19152379 PMCID: PMC4876875 DOI: 10.1002/cne.21948] [Citation(s) in RCA: 160] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In most insects with olfactory glomeruli, each side of the brain possesses a mushroom body equipped with calyces supplied by olfactory projection neurons. Kenyon cells providing dendrites to the calyces supply a pedunculus and lobes divided into subdivisions supplying outputs to other brain areas. It is with reference to these components that most functional studies are interpreted. However, mushroom body structures are diverse, adapted to different ecologies, and likely to serve various functions. In insects whose derived life styles preclude the detection of airborne odorants, there is a loss of the antennal lobes and attenuation or loss of the calyces. Such taxa retain mushroom body lobes that are as elaborate as those of mushroom bodies equipped with calyces. Antennal lobe loss and calycal regression also typify taxa with short nonfeeding adults, in which olfaction is redundant. Examples are cicadas and mayflies, the latter representing the most basal lineage of winged insects. Mushroom bodies of another basal taxon, the Odonata, possess a remnant calyx that may reflect the visual ecology of this group. That mushroom bodies persist in brains of secondarily anosmic insects suggests that they play roles in higher functions other than olfaction. Mushroom bodies are not ubiquitous: the most basal living insects, the wingless Archaeognatha, possess glomerular antennal lobes but lack mushroom bodies, suggesting that the ability to process airborne odorants preceded the acquisition of mushroom bodies. Archaeognathan brains are like those of higher malacostracans, which lack mushroom bodies but have elaborate olfactory centers laterally in the brain.
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Affiliation(s)
- Nicholas J. Strausfeld
- Arizona Research Laboratories, Division of Neurobiology, University of Arizona, Tucson, AZ 85721, USA
| | - Irina Sinakevitch
- IBDML-UMR 6216, Case 907 Parc Scientifique de Luminy, 13288 Marseille, Cedex 9, France
| | - Sheena M. Brown
- Arizona Research Laboratories, Division of Neurobiology, University of Arizona, Tucson, AZ 85721, USA
| | - Sarah M. Farris
- Department of Biology, West Virginia University, Morgantown, WV 26506, USA
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Protein kinase A inhibits a consolidated form of memory in Drosophila. Proc Natl Acad Sci U S A 2008; 105:20976-81. [PMID: 19075226 DOI: 10.1073/pnas.0810119105] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Increasing activity of the cAMP/protein kinase A (PKA) pathway has often been proposed as an approach to improve memory in various organisms. However, here we demonstrate that single-point mutations, which decrease PKA activity, dramatically improve aversive olfactory memory in Drosophila. These mutations do not affect formation of early memory phases or of protein synthesis-dependent long-term memory but do cause a significant increase in a specific consolidated form of memory, anesthesia-resistant memory. Significantly, heterozygotes of null mutations in PKA are sufficient to cause this memory increase. Expressing a PKA transgene in the mushroom bodies, brain structures critical for memory formation in Drosophila, reduces memory back to wild-type levels. These results indicate that although PKA is critical for formation of several memory phases, it also functions to inhibit at least one memory phase.
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Suyama R, Jenny A, Curado S, Pellis-van Berkel W, Ephrussi A. The actin-binding protein Lasp promotes Oskar accumulation at the posterior pole of the Drosophila embryo. Development 2008; 136:95-105. [PMID: 19036801 DOI: 10.1242/dev.027698] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
During Drosophila oogenesis, Oskar mRNA is transported to the posterior pole of the oocyte, where it is locally translated and induces germ-plasm assembly. Oskar protein recruits all of the components necessary for the establishment of posterior embryonic structures and of the germline. Tight localization of Oskar is essential, as its ectopic expression causes severe patterning defects. Here, we show that the Drosophila homolog of mammalian Lasp1 protein, an actin-binding protein previously implicated in cell migration in vertebrate cell culture, contributes to the accumulation of Oskar protein at the posterior pole of the embryo. The reduced number of primordial germ cells in embryos derived from lasp mutant females can be rescued only with a form of Lasp that is capable of interacting with Oskar, revealing the physiological importance of the Lasp-Oskar interaction.
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Affiliation(s)
- Ritsuko Suyama
- Developmental Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, D-69117 Heidelberg, Germany
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45
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Stimulus-induced translocation of the protein kinase A catalytic subunit to the apical membrane in blowfly salivary glands. Cell Tissue Res 2008; 335:657-62. [PMID: 18766382 DOI: 10.1007/s00441-008-0673-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2008] [Accepted: 07/16/2008] [Indexed: 10/21/2022]
Abstract
Secretion in blowfly (Calliphora vicina) salivary glands is regulated by the neurohormone serotonin (5-HT), which activates the InsP(3)/Ca(2+) pathway and the cAMP/protein kinase A (PKA) pathway in the secretory cells. The latter signaling cascade induces the activation of a vacuolar H(+)-ATPase on the apical membrane. Here, we have determined the distribution of PKA by using antibodies against the PKA regulatory subunit-II (PKA-RII) and the PKA catalytic subunit (PKA-C) of Drosophila. PKA is present in high concentrations within the secretory cells. PKA-RII and PKA-C co-distribute in non-stimulated glands, being enriched in the basal portion of the secretory cells. Exposure to 8-CPT-cAMP or 5-HT induces the translocation of PKA-C to the apical membrane, whereas the PKA-RII distribution remains unchanged. The recruitment of PKA-C to the apical membrane corroborates our hypothesis that vacuolar H(+)-ATPase, which is enriched in this membrane domain, is a target protein for PKA.
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46
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Abstract
The ensheathment of neurons and their axons creates an ion-sensitive microenvironment that allows rapid conduction of nerve impulses. One of the fundamental questions about axonal ensheathment is how insulating glial cells wrap around axons. The mechanisms that underlie insulation of axons in invertebrates and vertebrates are not fully understood. In the present article we address cellular aspects of axonal ensheathment in Drosophila by taking advantage of glial mutants that illustrate a range of phenotypic defects including ensheathment of axons. From the findings of these mutant studies, we summarize that loss of glial cells, defects in glial membrane wrapping, failure of glial migration, and loss of specialized ladderlike septate junctions between ensheathing glial membranes result in axon-glial functional defects. These studies provide a broad perspective on glial ensheathment of axons in Drosophila and key insights into the anatomical and cellular aspects of axonal insulation. Given the powerful genetic approaches available in Drosophila, the axonal ensheathment process can be dissected in great detail to reveal the fundamental principles of ensheathment. These observations will be relevant to understanding the very similar processes in vertebrates, where defects in glial cell functions lead to devastating neurological diseases.
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Affiliation(s)
- Swati Banerjee
- Department of Cell and Molecular Physiology, Neurodevelopmental Disorders Research Center, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599-7545, USA
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Berger KH, Kong EC, Dubnau J, Tully T, Moore MS, Heberlein U. Ethanol sensitivity and tolerance in long-term memory mutants of Drosophila melanogaster. Alcohol Clin Exp Res 2008; 32:895-908. [PMID: 18435628 DOI: 10.1111/j.1530-0277.2008.00659.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND It has become increasingly clear that molecular and neural mechanisms underlying learning and memory and drug addiction are largely shared. To confirm and extend these findings, we analyzed ethanol-responsive behaviors of a collection of Drosophila long-term memory mutants. METHODS For each mutant, sensitivity to the acute uncoordinating effects of ethanol was quantified using the inebriometer. Additionally, 2 distinct forms of ethanol tolerance were measured: rapid tolerance, which develops in response to a single brief exposure to a high concentration of ethanol vapor; and chronic tolerance, which develops following a sustained low-level exposure. RESULTS Several mutants were identified with altered sensitivity, rapid or chronic tolerance, while a number of mutants exhibited multiple defects. CONCLUSIONS The corresponding genes in these mutants represent areas of potential overlap between learning and memory and behavioral responses to alcohol. These genes also define components shared between different ethanol behavioral responses.
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Affiliation(s)
- Karen H Berger
- Ernest Gallo Clinic and Research Center, University of California, San Francisco, Emeryville, California 94608, USA.
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Yamazaki D, Horiuchi J, Nakagami Y, Nagano S, Tamura T, Saitoe M. The Drosophila DCO mutation suppresses age-related memory impairment without affecting lifespan. Nat Neurosci 2007; 10:478-84. [PMID: 17322874 DOI: 10.1038/nn1863] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2006] [Accepted: 02/01/2007] [Indexed: 11/08/2022]
Abstract
The study of age-related memory impairment (AMI) has been hindered by a lack of AMI-specific mutants. In a screen for such mutants in Drosophila melanogaster, we found that heterozygous mutations of DCO (DCO/+), which encodes the major catalytic subunit of cAMP-dependent protein kinase (PKA), delay AMI more than twofold without affecting lifespan or memory at early ages. AMI is restored when a DCO transgene is expressed in mushroom bodies, structures important for olfactory memory formation. Furthermore, increasing cAMP and PKA activity in mushroom bodies causes premature AMI, whereas reducing activity suppresses AMI. In Drosophila AMI consists of a specific reduction in memory dependent on the amnesiac (amn) gene. amn encodes putative neuropeptides that have been proposed to regulate cAMP levels in mushroom bodies. Notably, both the memory and AMI defects of amn mutants are restored in amn;DCO/+ double mutants, suggesting that AMI is caused by an age-related disruption of amn-dependent memory via PKA activity in mushroom bodies.
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Affiliation(s)
- Daisuke Yamazaki
- Tokyo Metropolitan Institute for Neuroscience, Fuchu, Tokyo 183-8526, Japan
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49
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SAKAI T, KITAMOTO T. Clock, love and memory: Circadian and non-circadian regulation of Drosophila mating behavior by clock genes. Sleep Biol Rhythms 2006. [DOI: 10.1111/j.1479-8425.2006.00224.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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50
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Zhou Q, Apionishev S, Kalderon D. The contributions of protein kinase A and smoothened phosphorylation to hedgehog signal transduction in Drosophila melanogaster. Genetics 2006; 173:2049-62. [PMID: 16783001 PMCID: PMC1569721 DOI: 10.1534/genetics.106.061036] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Protein kinase A (PKA) silences the Hedgehog (Hh) pathway in Drosophila in the absence of ligand by phosphorylating the pathway's transcriptional effector, Cubitus interruptus (Ci). Smoothened (Smo) is essential for Hh signal transduction but loses activity if three specific PKA sites or adjacent PKA-primed casein kinase 1 (CK1) sites are replaced by alanine residues. Conversely, Smo becomes constitutively active if acidic residues replace those phosphorylation sites. These observations suggest an essential positive role for PKA in responding to Hh. However, direct manipulation of PKA activity has not provided strong evidence for positive effects of PKA, with the notable exception of a robust induction of Hh target genes by PKA hyperactivity in embryos. Here we show that the latter response is mediated principally by regulatory elements other than Ci binding sites and not by altered Smo phosphorylation. Also, the failure of PKA hyperactivity to induce Hh target genes strongly through Smo phosphorylation cannot be attributed to the coincident phosphorylation of PKA sites on Ci. Finally, we show that Smo containing acidic residues at PKA and CK1 sites can be stimulated further by Hh and acts through Hh pathways that both stabilize Ci-155 and use Fused kinase activity to increase the specific activity of Ci-155.
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Affiliation(s)
- Qianhe Zhou
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
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