1
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Moody JC, Qadota H, Benian GM. The RhoGAP RRC-1 is required for the assembly or stability of integrin adhesion complexes and is a member of the PIX pathway in muscle. Mol Biol Cell 2024; 35:ar58. [PMID: 38446619 PMCID: PMC11064667 DOI: 10.1091/mbc.e23-03-0095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 02/20/2024] [Accepted: 02/28/2024] [Indexed: 03/08/2024] Open
Abstract
GTPases cycle between active GTP bound and inactive GDP bound forms. Exchange of GDP for GTP is catalyzed by guanine nucleotide exchange factors (GEFs). GTPase activating proteins (GAPs) accelerate GTP hydrolysis, to promote the GDP bound form. We reported that the RacGEF, PIX-1, is required for assembly of integrin adhesion complexes (IAC) in striated muscle of Caenorhabditis elegans. In C. elegans, IACs are found at the muscle cell boundaries (MCBs), and bases of sarcomeric M-lines and dense bodies (Z-disks). Screening C. elegans mutants in proteins containing RhoGAP domains revealed that loss of function of rrc-1 results in loss of IAC components at MCBs, disorganization of M-lines and dense bodies, and reduced whole animal locomotion. RRC-1 localizes to MCBs, like PIX-1. The localization of RRC-1 at MCBs requires PIX-1, and the localization of PIX-1 requires RRC-1. Loss of function of CED-10 (Rac) shows lack of PIX-1 and RRC-1 at MCBs. RRC-1 exists in a complex with PIX-1. Transgenic rescue of rrc-1 was achieved with wild type RRC-1 but not RRC-1 with a missense mutation in a highly conserved residue of the RhoGAP domain. Our results are consistent with RRC-1 being a RhoGAP for the PIX pathway in muscle.
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Affiliation(s)
| | - Hiroshi Qadota
- Department of Pathology, Emory University, Atlanta, GA 30322
| | - Guy M. Benian
- Department of Pathology, Emory University, Atlanta, GA 30322
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2
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Jing T, Wu Y, Yu Y, Li J, Mu X, Xu L, Wang X, Qi G, Tang J, Wang D, Yang S, Hua J, Gou M. Copine proteins are required for brassinosteroid signaling in maize and Arabidopsis. Nat Commun 2024; 15:2028. [PMID: 38459051 PMCID: PMC10923931 DOI: 10.1038/s41467-024-46289-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 02/21/2024] [Indexed: 03/10/2024] Open
Abstract
Copine proteins are highly conserved and ubiquitously found in eukaryotes, and their indispensable roles in different species were proposed. However, their exact function remains unclear. The phytohormone brassinosteroids (BRs) play vital roles in plant growth, development and environmental responses. A key event in effective BR signaling is the formation of functional BRI1-SERK receptor complex and subsequent transphosphorylation upon ligand binding. Here, we demonstrate that BONZAI (BON) proteins, which are plasma membrane-associated copine proteins, are critical components of BR signaling in both the monocot maize and the dicot Arabidopsis. Biochemical and molecular analyses reveal that BON proteins directly interact with SERK kinases, thereby ensuring effective BRI1-SERK interaction and transphosphorylation. This study advances the knowledge on BR signaling and provides an important target for optimizing valuable agronomic traits, it also opens a way to study steroid hormone signaling and copine proteins of eukaryotes in a broader perspective.
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Affiliation(s)
- Teng Jing
- State Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou, Henan, China
| | - Yuying Wu
- State Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou, Henan, China
| | - Yanwen Yu
- State Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou, Henan, China
| | - Jiankun Li
- State Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou, Henan, China
| | - Xiaohuan Mu
- State Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou, Henan, China
| | - Liping Xu
- State Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou, Henan, China
| | - Xi Wang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing, China
| | - Guang Qi
- State Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou, Henan, China
| | - Jihua Tang
- State Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou, Henan, China
- The Shennong Laboratory, Zhengzhou, Henan, China
| | - Daowen Wang
- State Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou, Henan, China
| | - Shuhua Yang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing, China
| | - Jian Hua
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, USA
| | - Mingyue Gou
- State Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou, Henan, China.
- The Shennong Laboratory, Zhengzhou, Henan, China.
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3
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Martin SCT, Qadota H, Oberhauser AF, Hardin J, Benian GM. FARL-11 (STRIP1/2) is required for sarcomere and sarcoplasmic reticulum organization in C. elegans. Mol Biol Cell 2023; 34:ar86. [PMID: 37314837 PMCID: PMC10398898 DOI: 10.1091/mbc.e23-03-0083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 05/16/2023] [Accepted: 06/06/2023] [Indexed: 06/15/2023] Open
Abstract
Protein phosphatase 2A (PP2A) functions in a variety of cellular contexts. PP2A can assemble into four different complexes based on the inclusion of different regulatory or targeting subunits. The B''' regulatory subunit "striatin" forms the STRIPAK complex consisting of striatin, a catalytic subunit (PP2AC), striatin-interacting protein 1 (STRIP1), and MOB family member 4 (MOB4). In yeast and Caenorhabditis elegans, STRIP1 is required for formation of the endoplasmic reticulum (ER). Because the sarcoplasmic reticulum (SR) is the highly organized muscle-specific version of ER, we sought to determine the function of the STRIPAK complex in muscle using C. elegans. CASH-1 (striatin) and FARL-11 (STRIP1/2) form a complex in vivo, and each protein is localized to SR. Missense mutations and single amino acid losses in farl-11 and cash-1 each result in similar sarcomere disorganization. A missense mutation in farl-11 shows no detectable FARL-11 protein by immunoblot, disruption of SR organization around M-lines, and altered levels of the SR Ca+2 release channel UNC-68.
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Affiliation(s)
| | - Hiroshi Qadota
- Department of Pathology, Emory University, Atlanta, GA 30322
| | - Andres F. Oberhauser
- Department of Neurobiology, The University of Texas Medical Branch, Galveston, TX 77555
| | - Jeff Hardin
- Biophysics Program, University of Wisconsin-Madison, Madison, WI 53706
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI 53706
| | - Guy M. Benian
- Department of Pathology, Emory University, Atlanta, GA 30322
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Martin SCT, Qadota H, Oberhauser AF, Hardin J, Benian GM. FARL-11 (STRIP1/2) is Required for Sarcomere and Sarcoplasmic Reticulum Organization in C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.05.531173. [PMID: 36945551 PMCID: PMC10028798 DOI: 10.1101/2023.03.05.531173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
Protein phosphatase 2A (PP2A) functions in a variety of cellular contexts. PP2A can assemble into four different complexes based on the inclusion of different regulatory or targeting subunits. The B''' regulatory subunit "striatin" forms the STRIPAK complex consisting of striatin, a catalytic subunit (PP2AC), striatin interacting protein 1 (STRIP1), and MOB family member 4 (MOB4). In yeast and C. elegans, STRIP1 is required for formation of the endoplasmic reticulum (ER). Since the sarcoplasmic reticulum (SR) is the highly organized muscle-specific version of ER, we sought to determine the function of the STRIPAK complex in muscle using C. elegans . CASH-1 (striatin) and FARL-11 (STRIP1/2) form a complex in vivo , and each protein is localized to SR. Missense mutations and single amino acid losses in farl-11 and cash-1 each result in similar sarcomere disorganization. A missense mutation in farl-11 shows no detectable FARL-11 protein by immunoblot, disruption of SR organization around M-lines, and altered levels of the SR Ca +2 release channel UNC-68. Summary Protein phosphatase 2A forms a STRIPAK complex when it includes the targeting B''' subunit "striatin" and STRIP1. STRIP1 is required for formation of ER. We show that in muscle STRIP1 is required for organization of SR and sarcomeres.
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Ain U, Firdaus H. Parvin: A hub of intracellular signalling pathways regulating cellular behaviour and disease progression. Acta Histochem 2022; 124:151935. [PMID: 35932544 DOI: 10.1016/j.acthis.2022.151935] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Revised: 07/27/2022] [Accepted: 07/27/2022] [Indexed: 11/15/2022]
Abstract
α-actinin superfamily houses the family of parvins, comprising α, β and γ isoforms in the vertebrates and a single orthologue in the invertebrates. Parvin as an adaptor protein is a member of the ternary IPP-complex including Integrin Linked Kinase (ILK) and particularly-interesting-Cys-His-rich protein (PINCH). Each of the complex proteins showed a conserved lineage and was principally used by the evolutionarily primitive integrin-adhesome machinery to regulate cellular behaviour and signalling pathways. Parvin facilitated integrin mediated integration of the extracellular matrix with cytoskeletal framework culminating in regulation of cellular adhesion and spreading, cytoskeleton reorganisation and cell survival. Studies have established role of parvin in pregnancy, lactation, matrix degradation, blood vessel formation and in several diseases such as cancer, NAFLD and cardiac diseases etc. This review narrates the history of parvin discovery, its elaborate gene structure and conservation across phyla including cellular expression, localisation and interacting partners in vertebrates as well as invertebrates. The review further discusses how parvin acts as an epicentre of signalling pathways, its associated mutants and diseased conditions.
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Affiliation(s)
- Ushashi Ain
- Department of Life Sciences, Central University of Jharkhand, CTI Campus, Ratu-Lohardaga Road, Ranchi 835205, India
| | - Hena Firdaus
- Department of Life Sciences, Central University of Jharkhand, CTI Campus, Ratu-Lohardaga Road, Ranchi 835205, India.
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6
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Qadota H, McPherson A, Corbitt R, Dackowski EK, Matsunaga Y, Oberhauser AF, Benian GM. Genetic analysis suggests a surface of PAT-4 (ILK) that interacts with UNC-112 (kindlin). G3 GENES|GENOMES|GENETICS 2022; 12:6583192. [PMID: 35536217 PMCID: PMC9258589 DOI: 10.1093/g3journal/jkac117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 05/05/2022] [Indexed: 11/12/2022]
Abstract
Abstract
Integrin plays a crucial role in the attachment of cells to the extracellular matrix. Integrin recruits many proteins intracellularly, including a 4-protein complex (kindlin, ILK, PINCH, and parvin). Caenorhabditis elegans muscle provides an excellent model to study integrin adhesion complexes. In Caenorhabditis elegans, UNC-112 (kindlin) binds to the cytoplasmic tail of PAT-3 (β-integrin) and to PAT-4 (ILK). We previously reported that PAT-4 binding to UNC-112 is essential for the binding of UNC-112 to PAT-3. Although there are crystal structures for ILK and a kindlin, there is no co-crystal structure available. To understand the molecular interaction between PAT-4 and UNC-112, we took a genetic approach. First, using a yeast 2-hybrid method, we isolated mutant PAT-4 proteins that cannot bind to UNC-112 and then isolated suppressor mutant UNC-112 proteins that restore interaction with mutant PAT-4 proteins. Second, we demonstrated that these mutant PAT-4 proteins cannot localize to attachment structures in nematode muscle, but upon co-expression of an UNC-112 suppressor mutant protein, mutant PAT-4 proteins could localize to attachment structures. Third, overexpression of a PAT-4 mutant results in the disorganization of adhesion plaques at muscle cell boundaries and co-expression of the UNC-112 suppressor mutant protein alleviates this defect. Thus, we demonstrate that UNC-112 binding to PAT-4 is required for the localization and function of PAT-4 in integrin adhesion complexes in vivo. The missense mutations were mapped onto homology models of PAT-4 and UNC-112, and taking into account previously isolated mutations, we suggest a surface of PAT-4 that binds to UNC-112.
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Affiliation(s)
- Hiroshi Qadota
- Department of Pathology, Emory University , Atlanta, GA 30322, USA
| | - Annie McPherson
- Department of Pathology, Emory University , Atlanta, GA 30322, USA
| | - Rachel Corbitt
- Department of Pathology, Emory University , Atlanta, GA 30322, USA
| | | | - Yohei Matsunaga
- Department of Pathology, Emory University , Atlanta, GA 30322, USA
| | - Andres F Oberhauser
- Department of Neuroscience, Cell Biology and Anatomy, University of Texas Medical Branch , Galveston, TX 77555, USA
| | - Guy M Benian
- Department of Pathology, Emory University , Atlanta, GA 30322, USA
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7
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Differential regulation of degradation and immune pathways underlies adaptation of the ectosymbiotic nematode Laxus oneistus to oxic-anoxic interfaces. Sci Rep 2022; 12:9725. [PMID: 35697683 PMCID: PMC9192688 DOI: 10.1038/s41598-022-13235-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 05/13/2022] [Indexed: 11/09/2022] Open
Abstract
Eukaryotes may experience oxygen deprivation under both physiological and pathological conditions. Because oxygen shortage leads to a reduction in cellular energy production, all eukaryotes studied so far conserve energy by suppressing their metabolism. However, the molecular physiology of animals that naturally and repeatedly experience anoxia is underexplored. One such animal is the marine nematode Laxus oneistus. It thrives, invariably coated by its sulfur-oxidizing symbiont Candidatus Thiosymbion oneisti, in anoxic sulfidic or hypoxic sand. Here, transcriptomics and proteomics showed that, whether in anoxia or not, L. oneistus mostly expressed genes involved in ubiquitination, energy generation, oxidative stress response, immune response, development, and translation. Importantly, ubiquitination genes were also highly expressed when the nematode was subjected to anoxic sulfidic conditions, together with genes involved in autophagy, detoxification and ribosome biogenesis. We hypothesize that these degradation pathways were induced to recycle damaged cellular components (mitochondria) and misfolded proteins into nutrients. Remarkably, when L. oneistus was subjected to anoxic sulfidic conditions, lectin and mucin genes were also upregulated, potentially to promote the attachment of its thiotrophic symbiont. Furthermore, the nematode appeared to survive oxygen deprivation by using an alternative electron carrier (rhodoquinone) and acceptor (fumarate), to rewire the electron transfer chain. On the other hand, under hypoxia, genes involved in costly processes (e.g., amino acid biosynthesis, development, feeding, mating) were upregulated, together with the worm's Toll-like innate immunity pathway and several immune effectors (e.g., bactericidal/permeability-increasing proteins, fungicides). In conclusion, we hypothesize that, in anoxic sulfidic sand, L. oneistus upregulates degradation processes, rewires the oxidative phosphorylation and reinforces its coat of bacterial sulfur-oxidizers. In upper sand layers, instead, it appears to produce broad-range antimicrobials and to exploit oxygen for biosynthesis and development.
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8
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Goel M, Aponte AM, Wistow G, Badea TC. Molecular studies into cell biological role of Copine-4 in Retinal Ganglion Cells. PLoS One 2021; 16:e0255860. [PMID: 34847148 PMCID: PMC8631636 DOI: 10.1371/journal.pone.0255860] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 11/12/2021] [Indexed: 11/19/2022] Open
Abstract
The molecular mechanisms underlying morphological diversity in retinal cell types are poorly understood. We have previously reported that several members of the Copine family of Ca-dependent membrane adaptors are expressed in Retinal Ganglion Cells and transcriptionally regulated by Brn3 transcription factors. Several Copines are enriched in the retina and their over-expression leads to morphological changes -formation of elongated processes-, reminiscent of neurites, in HEK293 cells. However, the role of Copines in the retina is largely unknown. We now investigate Cpne4, a Copine whose expression is restricted to Retinal Ganglion Cells. Over-expression of Cpne4 in RGCs in vivo led to formation of large varicosities on the dendrites but did not otherwise visibly affect dendrite or axon formation. Protein interactions studies using yeast two hybrid analysis from whole retina cDNA revealed two Cpne4 interacting proteins-Host Cell Factor 1 and Morn2. Mass Spectrometry analysis of retina lysate pulled down using Cpne4 or its vonWillebrand A domain showed 207 interacting proteins. A Gene Ontology analysis of the discovered proteins suggests that Cpne4 is involved in several metabolic and signaling pathways in the retina.
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Affiliation(s)
- Manvi Goel
- Retinal Circuit Development & Genetics Unit, Neurobiology Neurodegeneration & Repair Laboratory, NEI, National Institutes of Health, Bethesda, Maryland, United States of America
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, United States of America
| | - Angel M. Aponte
- Proteomics Core, NHLBI, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Graeme Wistow
- Section on Molecular Structure and Functional Genomics, NEI, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Tudor C. Badea
- Retinal Circuit Development & Genetics Unit, Neurobiology Neurodegeneration & Repair Laboratory, NEI, National Institutes of Health, Bethesda, Maryland, United States of America
- Faculty of Medicine, Research and Development Institute, Transilvania University of Brasov, Brasov, Romania
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9
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Porto D, Matsunaga Y, Franke B, Williams RM, Qadota H, Mayans O, Benian GM, Lu H. Conformational changes in twitchin kinase in vivo revealed by FRET imaging of freely moving C. elegans. eLife 2021; 10:e66862. [PMID: 34569929 PMCID: PMC8523150 DOI: 10.7554/elife.66862] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Accepted: 09/24/2021] [Indexed: 02/07/2023] Open
Abstract
The force-induced unfolding and refolding of proteins is speculated to be a key mechanism in the sensing and transduction of mechanical signals in the living cell. Yet, little evidence has been gathered for its existence in vivo. Prominently, stretch-induced unfolding is postulated to be the activation mechanism of the twitchin/titin family of autoinhibited sarcomeric kinases linked to the mechanical stress response of muscle. To test the occurrence of mechanical kinase activation in living working muscle, we generated transgenic Caenorhabditis elegans expressing twitchin containing FRET moieties flanking the kinase domain and developed a quantitative technique for extracting FRET signals in freely moving C. elegans, using tracking and simultaneous imaging of animals in three channels (donor fluorescence, acceptor fluorescence, and transmitted light). Computer vision algorithms were used to extract fluorescence signals and muscle contraction states in each frame, in order to obtain fluorescence and body curvature measurements with spatial and temporal precision in vivo. The data revealed statistically significant periodic changes in FRET signals during muscle activity, consistent with a periodic change in the conformation of twitchin kinase. We conclude that stretch-unfolding of twitchin kinase occurs in the active muscle, whereby mechanical activity titrates the signaling pathway of this cytoskeletal kinase. We anticipate that the methods we have developed here could be applied to obtaining in vivo evidence for force-induced conformational changes or elastic behavior of other proteins not only in C. elegans but in other animals in which there is optical transparency (e.g., zebrafish).
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Affiliation(s)
- Daniel Porto
- Interdisciplinary Bioengineering Program, Georgia Institute of TechnologyAtlantaUnited States
| | - Yohei Matsunaga
- Department of Pathology, Emory UniversityAtlantaUnited States
| | - Barbara Franke
- Department of Biology, University of KonstanzKonstanzGermany
| | - Rhys M Williams
- Department of Biology, University of KonstanzKonstanzGermany
| | - Hiroshi Qadota
- Department of Pathology, Emory UniversityAtlantaUnited States
| | - Olga Mayans
- Department of Biology, University of KonstanzKonstanzGermany
| | - Guy M Benian
- Department of Pathology, Emory UniversityAtlantaUnited States
| | - Hang Lu
- Interdisciplinary Bioengineering Program, Georgia Institute of TechnologyAtlantaUnited States
- School of Chemical & Biomolecular Engineering, Georgia Institute of TechnologyAtlantaUnited States
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10
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Tang H, Cui M, Han M. Fatty acids impact sarcomere integrity through myristoylation and ER homeostasis. Cell Rep 2021; 36:109539. [PMID: 34407398 PMCID: PMC8404530 DOI: 10.1016/j.celrep.2021.109539] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 06/04/2021] [Accepted: 07/26/2021] [Indexed: 01/01/2023] Open
Abstract
Decreased ability to maintain tissue integrity is critically involved in aging and degenerative diseases. Fatty acid (FA) metabolism has a profound impact on animal development and tissue maintenance, but our understanding of the underlying mechanisms is limited. We investigated whether and how FA abundance affects muscle integrity using Caenorhabditis elegans. We show that reducing the overall FA level by blocking FA biosynthesis or inhibiting protein myristoylation leads to disorganization of sarcomere structure and adult-onset paralysis. Further analysis indicates that myristoylation of two ARF guanosine triphosphatases (GTPases) critically mediates the effect of FA deficiency on sarcomere integrity through inducing endoplasmic reticulum (ER) stress and ER unfolded protein response (UPRER), which in turn leads to reduction of the level of sarcomere component PINCH and myosin disorganization. We thus present a mechanism that links FA signal, protein myristoylation, and ER homeostasis with muscle integrity, which provides valuable insights into the regulatory role of nutrients and ER homeostasis in muscle maintenance. Tang et al. show that fatty acid deficiency causes defects in muscle integrity in the nematode C. elegans and such an impact is mediated by deficiency of lipid modification of specific proteins in the muscle that in turn triggers ER stress and muscle disorganization. The results reveal the regulatory roles of fatty acids and ER homeostasis in muscle maintenance.
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Affiliation(s)
- Hongyun Tang
- Department of MCDB, University of Colorado Boulder, Boulder, CO 80309, USA; Key Laboratory of Growth Regulation and Transformation Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou 310024, Zhejiang Province, China; Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
| | - Mingxue Cui
- Department of MCDB, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Min Han
- Department of MCDB, University of Colorado Boulder, Boulder, CO 80309, USA.
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11
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Moody JC, Qadota H, Reedy AR, Okafor CD, Shanmugan N, Matsunaga Y, Christian CJ, Ortlund EA, Benian GM. The Rho-GEF PIX-1 directs assembly or stability of lateral attachment structures between muscle cells. Nat Commun 2020; 11:5010. [PMID: 33024114 PMCID: PMC7538588 DOI: 10.1038/s41467-020-18852-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 09/15/2020] [Indexed: 01/11/2023] Open
Abstract
PIX proteins are guanine nucleotide exchange factors (GEFs) that activate Rac and Cdc42, and are known to have numerous functions in various cell types. Here, we show that a PIX protein has an important function in muscle. From a genetic screen in C. elegans, we found that pix-1 is required for the assembly of integrin adhesion complexes (IACs) at borders between muscle cells, and is required for locomotion of the animal. A pix-1 null mutant has a reduced level of activated Rac in muscle. PIX-1 localizes to IACs at muscle cell boundaries, M-lines and dense bodies. Mutations in genes encoding proteins at known steps of the PIX signaling pathway show defects at muscle cell boundaries. A missense mutation in a highly conserved residue in the RacGEF domain results in normal levels of PIX-1 protein, but a reduced level of activated Rac in muscle, and abnormal IACs at muscle cell boundaries.
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Affiliation(s)
- Jasmine C Moody
- Department of Pathology, Emory University, Atlanta, GA, 30322, USA
| | - Hiroshi Qadota
- Department of Pathology, Emory University, Atlanta, GA, 30322, USA
| | - April R Reedy
- Department of Pathology, Emory University, Atlanta, GA, 30322, USA
| | - C Denise Okafor
- Department of Biochemistry, Emory University, Atlanta, GA, 30322, USA
| | - Niveda Shanmugan
- Department of Pathology, Emory University, Atlanta, GA, 30322, USA
| | - Yohei Matsunaga
- Department of Pathology, Emory University, Atlanta, GA, 30322, USA
| | | | - Eric A Ortlund
- Department of Biochemistry, Emory University, Atlanta, GA, 30322, USA
| | - Guy M Benian
- Department of Pathology, Emory University, Atlanta, GA, 30322, USA.
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12
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A Region of UNC-89 (Obscurin) Lying between Two Protein Kinase Domains Is a Highly Elastic Spring Required for Proper Sarcomere Organization. J Mol Biol 2020; 432:4799-4814. [PMID: 32645312 DOI: 10.1016/j.jmb.2020.06.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 06/07/2020] [Accepted: 06/25/2020] [Indexed: 12/17/2022]
Abstract
In Caenorhabditis elegans, unc-89 encodes a set of giant multi-domain proteins (up 8081 residues) localized to the M-lines of muscle sarcomeres and required for normal sarcomere organization and whole-animal locomotion. Multiple UNC-89 isoforms contain two protein kinase domains. There is conservation in arrangement of domains between UNC-89 and its two mammalian homologs, obscurin and SPEG: kinase, a non-domain region of 647-742 residues, Ig domain, Fn3 domain and a second kinase domain. In all three proteins, this non-domain "interkinase region" has low sequence complexity, has high proline content, and lacks predicted secondary structure. We report that a major portion of this interkinase (571 residues out of 647 residues) when examined by single molecule force spectroscopy in vitro displays the properties of a random coil and acts as an entropic spring. We used CRISPR/Cas9 to create nematodes carrying an in-frame deletion of the same 571-residue portion of the interkinase. These animals display severe disorganization of all portions of the sarcomere in body wall muscle. Super-resolution microscopy reveals extra, short-A-bands lying close to the outer muscle cell membrane and between normally spaced A-bands. Nematodes with this in-frame deletion show defective locomotion and muscle force generation. We designed our CRISPR-generatedin-frame deletion to contain an HA tag at the N terminus of the large UNC-89 isoforms. This HA tag results in normal organization of body wall muscle, but approximately half the normal levels of the giant UNC-89 isoforms, dis-organization of pharyngeal muscle, small body size, and reduced muscle force, likely due to poor nutritional uptake.
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Wight EM, Ide AD, Damer CK. Copine A regulates the size and exocytosis of contractile vacuoles and postlysosomes in Dictyostelium. FEBS Open Bio 2020; 10:979-994. [PMID: 32351039 PMCID: PMC7262877 DOI: 10.1002/2211-5463.12874] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 04/12/2020] [Accepted: 04/28/2020] [Indexed: 11/10/2022] Open
Abstract
Copines are a family of cytosolic proteins that associate with membranes in a calcium‐dependent manner and are found in many eukaryotic organisms. Dictyostelium discoideum has six copine genes (cpnA‐cpnF), and cells lacking cpnA(cpnA−) have defects in cytokinesis, chemotaxis, adhesion, and development. CpnA has also been shown to associate with the plasma membrane, contractile vacuoles (CV), and organelles of the endolysosomal pathway. Here, we use cpnA− cells to investigate the role of CpnA in CV function and endocytosis. When placed in water, cpnA− cells made abnormally large CVs that took longer to expel. Visualization of CVs with the marker protein GFP‐dajumin indicated that cpnA− cells had fewer CVs that sometimes refilled before complete emptying. In endocytosis assays, cpnA− cells took up small fluorescent beads by macropinocytosis at rates similar to parental cells. However, cpnA− cells reached a plateau sooner than parental cells and had less fluorescence at later time points. p80 antibody labeling of postlysosomes (PL) indicated that there were fewer and smaller PLs in cpnA− cells. In dextran pulse‐chase experiments, the number of PLs peaked earlier in cpnA− cells, and the PLs did not become as large and disappeared sooner as compared to parental cells. PLs in cpnA− cells were also shown to have more actin coats, suggesting CpnA may play a role in actin filament disassembly on PL membranes. Overall, these results indicate that CpnA is involved in the regulation of CV size and expulsion, and the maturation, size, and exocytosis of PLs.
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Affiliation(s)
- Elise M Wight
- Biology Department, Central Michigan University, Mount Pleasant, MI, USA
| | - Amber D Ide
- Biology Department, Central Michigan University, Mount Pleasant, MI, USA
| | - Cynthia K Damer
- Biology Department, Central Michigan University, Mount Pleasant, MI, USA
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Goel M, Li T, Badea TC. Differential expression and subcellular localization of Copines in mouse retina. J Comp Neurol 2019; 527:2245-2262. [PMID: 30866042 DOI: 10.1002/cne.24684] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 03/04/2019] [Accepted: 03/11/2019] [Indexed: 01/06/2023]
Abstract
Combinatorial expression of Brn3 transcription factors is required for the development of cell-specific morphologies in retinal ganglion cells (RGCs). The molecular mechanisms by which Brn3s regulate RGC type specific features are largely unexplored. We previously identified several members of the Copine (Cpne) family of molecules as potential targets of Brn3 transcription factors in the retina. We now use in situ hybridization and immunohistochemistry to characterize Copine expression in the postnatal and adult mouse retina. We find that Cpne5, 6, and 9 are expressed in the ganglion cell layer (GCL) and inner nuclear layer (INL) in both amacrine cells and RGCs. Cpne4 expression is restricted to one amacrine cell population of the INL, but is specifically expressed in RGCs in the GCL. Cpne4 expression in RGCs is regulated by Brn3b both cell autonomously (in Brn3b+ RGCs) and cell nonautonomously (in Brn3b- RGCs). Copines exhibit a variety of subcellular distributions when overexpressed in tissue culture cells (HEK293), and can induce the formation of elongated processes reminiscent of neurites in these non-neuronal cells. Our results suggest that Copines might be involved in a combinatorial fashion in Brn3b-dependent specification of RGC types. Given their expression profile and previously proven role as Ca2+ sensors, they may participate in the morphogenetic processes that shape RGC dendrite and axon formation at early postnatal ages.
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Affiliation(s)
- Manvi Goel
- Retinal Circuit Development & Genetics Unit, Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, NIH, Bethesda, Maryland
| | - Tiansen Li
- Retinal Cell Biology & Degeneration Section, Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, NIH, Bethesda, Maryland
| | - Tudor C Badea
- Retinal Circuit Development & Genetics Unit, Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, NIH, Bethesda, Maryland
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15
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Qadota H, Matsunaga Y, Bagchi P, Lange KI, Carrier KJ, Pols WV, Swartzbaugh E, Wilson KJ, Srayko M, Pallas DC, Benian GM. Protein phosphatase 2A is crucial for sarcomere organization in Caenorhabditis elegans striated muscle. Mol Biol Cell 2018; 29:2084-2097. [PMID: 29949401 PMCID: PMC6232960 DOI: 10.1091/mbc.e18-03-0192] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 06/12/2018] [Accepted: 06/18/2018] [Indexed: 01/06/2023] Open
Abstract
Protein phosphatase 2A (PP2A) is a heterotrimer composed of single catalytic and scaffolding subunits and one of several possible regulatory subunits. We identified PPTR-2, a regulatory subunit of PP2A, as a binding partner for the giant muscle protein UNC-89 (obscurin) in Caenorhabditis elegans. PPTR-2 is required for sarcomere organization when its paralogue, PPTR-1, is deficient. PPTR-2 localizes to the sarcomere at dense bodies and M-lines, colocalizing with UNC-89 at M-lines. PP2A components in C. elegans include one catalytic subunit LET-92, one scaffolding subunit (PAA-1), and five regulatory subunits (SUR-6, PPTR-1, PPTR-2, RSA-1, and CASH-1). In adult muscle, loss of function in any of these subunits results in sarcomere disorganization. rsa-1 mutants show an interesting phenotype: one of the two myosin heavy chains, MHC A, localizes as closely spaced double lines rather than single lines. This "double line" phenotype is found in rare missense mutants of the head domain of MHC B myosin, such as unc-54(s74). Analysis of phosphoproteins in the unc-54(s74) mutant revealed two additional phosphoserines in the nonhelical tailpiece of MHC A. Antibodies localize PPTR-1, PAA-1, and SUR-6 to I-bands and RSA-1 to M-lines and I-bands. Therefore, PP2A localizes to sarcomeres and functions in the assembly or maintenance of sarcomeres.
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Affiliation(s)
- Hiroshi Qadota
- Department of Pathology, Emory University, Atlanta, GA 30322
| | - Yohei Matsunaga
- Department of Pathology, Emory University, Atlanta, GA 30322
| | - Pritha Bagchi
- Emory Integrated Proteomics Core, Emory University, Atlanta, GA 30322
| | - Karen I. Lange
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
| | - Karma J. Carrier
- Department of Biochemistry and Winship Cancer Institute, Emory University, Atlanta, GA 30322
| | | | | | | | - Martin Srayko
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
| | - David C. Pallas
- Department of Biochemistry and Winship Cancer Institute, Emory University, Atlanta, GA 30322
| | - Guy M. Benian
- Department of Pathology, Emory University, Atlanta, GA 30322
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16
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Wang L, Geist J, Grogan A, Hu LYR, Kontrogianni-Konstantopoulos A. Thick Filament Protein Network, Functions, and Disease Association. Compr Physiol 2018; 8:631-709. [PMID: 29687901 DOI: 10.1002/cphy.c170023] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Sarcomeres consist of highly ordered arrays of thick myosin and thin actin filaments along with accessory proteins. Thick filaments occupy the center of sarcomeres where they partially overlap with thin filaments. The sliding of thick filaments past thin filaments is a highly regulated process that occurs in an ATP-dependent manner driving muscle contraction. In addition to myosin that makes up the backbone of the thick filament, four other proteins which are intimately bound to the thick filament, myosin binding protein-C, titin, myomesin, and obscurin play important structural and regulatory roles. Consistent with this, mutations in the respective genes have been associated with idiopathic and congenital forms of skeletal and cardiac myopathies. In this review, we aim to summarize our current knowledge on the molecular structure, subcellular localization, interacting partners, function, modulation via posttranslational modifications, and disease involvement of these five major proteins that comprise the thick filament of striated muscle cells. © 2018 American Physiological Society. Compr Physiol 8:631-709, 2018.
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Affiliation(s)
- Li Wang
- Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, Maryland, USA
| | - Janelle Geist
- Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, Maryland, USA
| | - Alyssa Grogan
- Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, Maryland, USA
| | - Li-Yen R Hu
- Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, Maryland, USA
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17
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Loveless T, Qadota H, Benian GM, Hardin J. Caenorhabditis elegans SORB-1 localizes to integrin adhesion sites and is required for organization of sarcomeres and mitochondria in myocytes. Mol Biol Cell 2017; 28:3621-3633. [PMID: 28978740 PMCID: PMC5706990 DOI: 10.1091/mbc.e16-06-0455] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 09/18/2017] [Accepted: 09/25/2017] [Indexed: 01/07/2023] Open
Abstract
We have identified and characterized sorb-1, the only sorbin and SH3 domain-containing protein family member in Caenorhabditis elegans SORB-1 is strongly localized to integrin adhesion complexes in larvae and adults, including adhesion plaques and dense bodies (Z-disks) of striated muscles and attachment plaques of smooth muscles. SORB-1 is recruited to the actin-binding, membrane-distal regions of dense bodies via its C-terminal SH3 domains in an ATN-1(α-actinin)- and ALP-1(ALP/Enigma)-dependent manner, where it contributes to the organization of sarcomeres. SORB-1 is also found in other tissues known to be under mechanical stress, including stress fibers in migratory distal tip cells and the proximal gonad sheath, where it becomes enriched in response to tissue distention. We provide evidence for a novel role for sorbin family proteins: SORB-1 is required for normal positioning of the mitochondrial network in muscle cells. Finally, we demonstrate that SORB-1 interacts directly with two other dense body components, DEB-1(vinculin) and ZYX-1(zyxin). This work establishes SORB-1 as a bona fide sorbin family protein-one of the late additions to the dense body complex and a conserved regulator of body wall muscle sarcomere organization and organelle positioning.
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Affiliation(s)
- Timothy Loveless
- Program in Cellular and Molecular Biology, University of Wisconsin-Madison, Madison, WI 53706
| | - Hiroshi Qadota
- Department of Pathology, Emory University, Atlanta, GA 30322
| | - Guy M Benian
- Department of Pathology, Emory University, Atlanta, GA 30322
| | - Jeff Hardin
- Program in Cellular and Molecular Biology, University of Wisconsin-Madison, Madison, WI 53706
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI 53706
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18
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Qadota H, Matsunaga Y, Nguyen KCQ, Mattheyses A, Hall DH, Benian GM. High-resolution imaging of muscle attachment structures in Caenorhabditis elegans. Cytoskeleton (Hoboken) 2017; 74:426-442. [PMID: 28921913 DOI: 10.1002/cm.21410] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Revised: 08/18/2017] [Accepted: 09/13/2017] [Indexed: 01/01/2023]
Abstract
We used structured illumination microscopy (SIM) to obtain super-resolution images of muscle attachment structures in Caenorhabditis elegans striated muscle. SIM imaging of M-line components revealed two patterns: PAT-3 (β-integrin) and proteins that interact in a complex with the cytoplasmic tail of β-integrin and localize to the basal muscle cell membrane [UNC-112 (kindlin), PAT-4 (ILK), UNC-97 (PINCH), PAT-6 (α-parvin), and UNC-95], are found in discrete, angled segments with gaps. In contrast, proteins localized throughout the depth of the M-line (UNC-89 (obscurin) and UNC-98) are imaged as continuous lines. Systematic immunostaining of muscle cell boundaries revealed that dense body components close to the basal muscle cell membrane also localize at cell boundaries. SIM imaging of muscle cell boundaries reveal "zipper-like" structures. Electron micrographs reveal electron dense material similar in appearance to dense bodies located adjacent to the basolateral cell membranes of adjacent muscle cells separated by ECM. Moreover, by EM, there are a variety of features of the muscle cell boundaries that help explain the zipper-like pattern of muscle protein localization observed by SIM. Short dense bodies in atn-1 mutants that are null for α-actinin and lack the deeper extensions of dense bodies, showed "zipper-like" structures by SIM similar to cell boundary structures, further indicating that the surface-proximal components of dense bodies form the "zipper-like" structures at cell boundaries. Moreover, mutants in thin and thick filament components do not have "dot-like" dense bodies, suggesting that myofilament tension is required for assembly or maintenance of proper dense body shape.
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Affiliation(s)
- Hiroshi Qadota
- Department of Pathology, Emory University, Atlanta, Georgia 30322
| | - Yohei Matsunaga
- Department of Pathology, Emory University, Atlanta, Georgia 30322
| | - Ken C Q Nguyen
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Alexa Mattheyses
- Department of Cell Biology, Emory University, Atlanta, Georgia 30322
| | - David H Hall
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Guy M Benian
- Department of Pathology, Emory University, Atlanta, Georgia 30322
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Randazzo D, Pierantozzi E, Rossi D, Sorrentino V. The potential of obscurin as a therapeutic target in muscle disorders. Expert Opin Ther Targets 2017; 21:897-910. [DOI: 10.1080/14728222.2017.1361931] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Davide Randazzo
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda
| | - Enrico Pierantozzi
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Daniela Rossi
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Vincenzo Sorrentino
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
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20
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Matsunaga Y, Hwang H, Franke B, Williams R, Penley M, Qadota H, Yi H, Morran LT, Lu H, Mayans O, Benian GM. Twitchin kinase inhibits muscle activity. Mol Biol Cell 2017; 28:1591-1600. [PMID: 28428253 PMCID: PMC5469603 DOI: 10.1091/mbc.e16-10-0707] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 04/04/2017] [Accepted: 04/11/2017] [Indexed: 01/03/2023] Open
Abstract
Muscles express giant polypeptides with kinase domains, but the in vivo significance of their catalytic activity has been unknown. Analysis of a mutant nematode that expresses the giant protein twitchin with a catalytically inactive kinase indicates that twitchin kinase inhibits muscle activity and is favored by selection. Muscle sarcomeres contain giant polypeptides composed of multiple immunoglobulin and fibronectin domains and one or two protein kinase domains. Although binding partners for a number of this family’s kinase domains have been identified, the catalytic necessity of these kinase domains remains unknown. In addition, various members of this kinase family are suspected pseudokinases with no or little activity. Here we address catalytic necessity for the first time, using the prototypic invertebrate representative twitchin (UNC-22) from Caenorhabditis elegans. In in vitro experiments, change of a conserved lysine (K) that is involved in ATP coordination to alanine (A) resulted in elimination of kinase activity without affecting the overall structure of the kinase domain. The same mutation, unc-22(sf21), was generated in the endogenous twitchin gene. The unc-22(sf21) worms have well-organized sarcomeres. However, unc-22(sf21) mutants move faster than wild-type worms and, by optogenetic experiments, contract more. Wild-type nematodes exhibited greater competitive fitness than unc-22(sf21) mutants. Thus the catalytic activity of twitchin kinase has a role in vivo, where it inhibits muscle activity and is likely maintained by selection.
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Affiliation(s)
- Yohei Matsunaga
- Department of Pathology, Emory University, Atlanta, GA 30322
| | - Hyundoo Hwang
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332
| | - Barbara Franke
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Rhys Williams
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - McKenna Penley
- Department of Biology, Emory University, Atlanta, GA 30322
| | - Hiroshi Qadota
- Department of Pathology, Emory University, Atlanta, GA 30322
| | - Hong Yi
- Apkarian Integrated Electron Microscopy Core, Emory University, Atlanta, GA 30322
| | - Levi T Morran
- Department of Biology, Emory University, Atlanta, GA 30322
| | - Hang Lu
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332
| | - Olga Mayans
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Guy M Benian
- Department of Pathology, Emory University, Atlanta, GA 30322
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21
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Manring HR, Carter OA, Ackermann MA. Obscure functions: the location-function relationship of obscurins. Biophys Rev 2017; 9:245-258. [PMID: 28510116 DOI: 10.1007/s12551-017-0254-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 03/05/2017] [Indexed: 12/18/2022] Open
Abstract
The obscurin family of polypeptides is essential for normal striated muscle function and contributes to the pathogenesis of fatal diseases, including cardiomyopathies and cancers. The single mammalian obscurin gene, OBSCN, gives rise to giant (∼800 kDa) and smaller (∼40-500 kDa) proteins that are composed of tandem adhesion and signaling motifs. Mammalian obscurin proteins are expressed in a variety of cell types, including striated muscles, and localize to distinct subcellular compartments where they contribute to diverse cellular processes. Obscurin homologs in Caenorhabditis elegans and Drosophila possess a similar domain architecture and are also expressed in striated muscles. The long sought after question, "what does obscurin do?" is complex and cannot be addressed without taking into consideration the subcellular distribution of these proteins and local isoform concentration. Herein, we present an overview of the functions of obscurins and begin to define the intricate relationship between their subcellular distributions and functions in striated muscles.
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Affiliation(s)
- Heather R Manring
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Ohio State University, Columbus, OH, 43210, USA.,Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Ohio State University, Columbus, OH, 43210, USA
| | - Olivia A Carter
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Ohio State University, Columbus, OH, 43210, USA.,Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Ohio State University, Columbus, OH, 43210, USA
| | - Maegen A Ackermann
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Ohio State University, Columbus, OH, 43210, USA. .,Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Ohio State University, Columbus, OH, 43210, USA.
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22
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Schiller NR, Duchesneau CD, Lane LS, Reedy AR, Manzon ER, Hoppe PE. The Role of the UNC-82 Protein Kinase in Organizing Myosin Filaments in Striated Muscle of Caenorhabditis elegans. Genetics 2017; 205:1195-1213. [PMID: 28040740 PMCID: PMC5340333 DOI: 10.1534/genetics.116.193029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 12/25/2016] [Indexed: 11/18/2022] Open
Abstract
We study the mechanisms that guide the formation and maintenance of the highly ordered actin-myosin cytoskeleton in striated muscle. The UNC-82 kinase of Caenorhabditis elegans is orthologous to mammalian kinases ARK5/NUAK1 and SNARK/NUAK2. UNC-82 localizes to the M-line, and is required for proper organization of thick filaments, but its substrate and mechanism of action are unknown. Antibody staining of three mutants with missense mutations in the UNC-82 catalytic domain revealed muscle structure that is less disorganized than in the null unc-82(0), but contained distinctive ectopic accumulations not found in unc-82(0) These accumulations contain paramyosin and myosin B, but lack myosin A and myosin A-associated proteins, as well as proteins of the integrin-associated complex. Fluorescently tagged missense mutant protein UNC-82 E424K localized normally in wild type; however, in unc-82(0), the tagged protein was found in the ectopic accumulations, which we also show to label with recently synthesized paramyosin. Recruitment of wild-type UNC-82::GFP to aggregates of differing protein composition in five muscle-affecting mutants revealed that colocalization of UNC-82 and paramyosin does not require UNC-96, UNC-98/ZnF, UNC-89/obscurin, CSN-5, myosin A, or myosin B individually. Dosage effects in paramyosin mutants suggest that UNC-82 acts as part of a complex, in which its stoichiometric relationship with paramyosin is critical. UNC-82 dosage affects muscle organization in the absence of paramyosin, perhaps through myosin B. We present evidence that the interaction of UNC-98/ZnF with myosin A is independent of UNC-82, and that UNC-82 acts upstream of UNC-98/ZnF in a pathway that organizes paramyosin during thick filament assembly.
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Affiliation(s)
- NaTasha R Schiller
- Department of Biological Sciences, Western Michigan University, Kalamazoo, Michigan 49008-5410
| | | | - Latrisha S Lane
- Department of Biological Sciences, Western Michigan University, Kalamazoo, Michigan 49008-5410
| | - April R Reedy
- Department of Biological Sciences, Western Michigan University, Kalamazoo, Michigan 49008-5410
| | - Emily R Manzon
- Department of Biological Sciences, Western Michigan University, Kalamazoo, Michigan 49008-5410
| | - Pamela E Hoppe
- Department of Biological Sciences, Western Michigan University, Kalamazoo, Michigan 49008-5410
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23
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Qadota H, Mayans O, Matsunaga Y, McMurry JL, Wilson KJ, Kwon GE, Stanford R, Deehan K, Tinley TL, Ngwa VM, Benian GM. The SH3 domain of UNC-89 (obscurin) interacts with paramyosin, a coiled-coil protein, in Caenorhabditis elegans muscle. Mol Biol Cell 2016; 27:1606-20. [PMID: 27009202 PMCID: PMC4865318 DOI: 10.1091/mbc.e15-09-0675] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 03/16/2016] [Accepted: 03/16/2016] [Indexed: 11/11/2022] Open
Abstract
UNC-89 is a giant polypeptide located at the sarcomeric M-line of Caenorhabditis elegans muscle. The human homologue is obscurin. To understand how UNC-89 is localized and functions, we have been identifying its binding partners. Screening a yeast two-hybrid library revealed that UNC-89 interacts with paramyosin. Paramyosin is an invertebrate-specific coiled-coil dimer protein that is homologous to the rod portion of myosin heavy chains and resides in thick filament cores. Minimally, this interaction requires UNC-89's SH3 domain and residues 294-376 of paramyosin and has a KD of ∼1.1 μM. In unc-89 loss-of-function mutants that lack the SH3 domain, paramyosin is found in accumulations. When the SH3 domain is overexpressed, paramyosin is mislocalized. SH3 domains usually interact with a proline-rich consensus sequence, but the region of paramyosin that interacts with UNC-89's SH3 is α-helical and lacks prolines. Homology modeling of UNC-89's SH3 suggests structural features that might be responsible for this interaction. The SH3-binding region of paramyosin contains a "skip residue," which is likely to locally unwind the coiled-coil and perhaps contributes to the binding specificity.
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Affiliation(s)
- Hiroshi Qadota
- Department of Pathology, Emory University, Atlanta, GA 30322
| | - Olga Mayans
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Yohei Matsunaga
- Department of Pathology, Emory University, Atlanta, GA 30322
| | - Jonathan L McMurry
- Department of Molecular and Cellular Biology, Kennesaw State University, Kennesaw, GA 30144
| | - Kristy J Wilson
- Department of Pathology, Emory University, Atlanta, GA 30322
| | - Grace E Kwon
- Department of Pathology, Emory University, Atlanta, GA 30322
| | - Rachel Stanford
- Department of Pathology, Emory University, Atlanta, GA 30322
| | - Kevin Deehan
- Department of Pathology, Emory University, Atlanta, GA 30322
| | - Tina L Tinley
- Department of Pathology, Emory University, Atlanta, GA 30322
| | - Verra M Ngwa
- Department of Molecular and Cellular Biology, Kennesaw State University, Kennesaw, GA 30144
| | - Guy M Benian
- Department of Pathology, Emory University, Atlanta, GA 30322
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Katzemich A, West RJH, Fukuzawa A, Sweeney ST, Gautel M, Sparrow J, Bullard B. Binding partners of the kinase domains in Drosophila obscurin and their effect on the structure of the flight muscle. J Cell Sci 2015; 128:3386-97. [PMID: 26251439 DOI: 10.1242/jcs.170639] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 07/27/2015] [Indexed: 01/15/2023] Open
Abstract
Drosophila obscurin (Unc-89) is a titin-like protein in the M-line of the muscle sarcomere. Obscurin has two kinase domains near the C-terminus, both of which are predicted to be inactive. We have identified proteins binding to the kinase domains. Kinase domain 1 bound Bällchen (Ball, an active kinase), and both kinase domains 1 and 2 bound MASK (a 400-kDa protein with ankyrin repeats). Ball was present in the Z-disc and M-line of the indirect flight muscle (IFM) and was diffusely distributed in the sarcomere. MASK was present in both the M-line and the Z-disc. Reducing expression of Ball or MASK by siRNA resulted in abnormalities in the IFM, including missing M-lines and multiple Z-discs. Obscurin was still present, suggesting that the kinase domains act as a scaffold binding Ball and MASK. Unlike obscurin in vertebrate skeletal muscle, Drosophila obscurin is necessary for the correct assembly of the IFM sarcomere. We show that Ball and MASK act downstream of obscurin, and both are needed for development of a well defined M-line and Z-disc. The proteins have not previously been identified in Drosophila muscle.
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Affiliation(s)
- Anja Katzemich
- Department of Biology, University of York, York YO10 5DD, UK
| | - Ryan J H West
- Department of Biology, University of York, York YO10 5DD, UK
| | - Atsushi Fukuzawa
- King's College BHF Centre, Cardiovascular Division, London SE1 1UL, UK
| | - Sean T Sweeney
- Department of Biology, University of York, York YO10 5DD, UK
| | - Mathias Gautel
- King's College BHF Centre, Cardiovascular Division, London SE1 1UL, UK
| | - John Sparrow
- Department of Biology, University of York, York YO10 5DD, UK
| | - Belinda Bullard
- Department of Biology, University of York, York YO10 5DD, UK
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Matsunaga Y, Qadota H, Furukawa M, Choe HH, Benian GM. Twitchin kinase interacts with MAPKAP kinase 2 in Caenorhabditis elegans striated muscle. Mol Biol Cell 2015; 26:2096-111. [PMID: 25851606 PMCID: PMC4472019 DOI: 10.1091/mbc.e14-05-1009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 04/01/2015] [Indexed: 01/13/2023] Open
Abstract
Titin-like giant polypeptides of muscle have protein kinase domains near their C-termini. These kinases are autoinhibited by portions of their own sequences. A putative activator for Caenorhabditis elegans twitchin kinase, MAK-1 (MAPKAP kinase 2), is expressed in nematode striated muscle, partially colocalizes with twitchin in sarcomeres, and binds to and phosphorylates twitchin kinase in vitro. In Caenorhabditis elegans, twitchin is a giant polypeptide located in muscle A-bands. The protein kinase of twitchin is autoinhibited by 45 residues upstream (NL) and 60 residues downstream (CRD) of the kinase catalytic core. Molecular dynamics simulation on a twitchin fragment revealed that the NL is released by pulling force. However, it is unclear how the CRD is removed. To identify proteins that may remove the CRD, we performed a yeast two-hybrid screen using twitchin kinase as bait. One interactor is MAK-1, C. elegans orthologue of MAPKAP kinase 2. MAPKAP kinase 2 is phosphorylated and activated by p38 MAP kinase. We demonstrate that the CRD of twitchin is important for binding to MAK-1. mak-1 is expressed in nematode body wall muscle, and antibodies to MAK-1 localize between and around Z-disk analogues and to the edge of A-bands. Whereas unc-22 mutants are completely resistant, mak-1 mutants are partially resistant to nicotine. MAK-1 can phosphorylate twitchin NL-Kin-CRD in vitro. Genetic data suggest the involvement of two other mak-1 paralogues and two orthologues of p38 MAP kinase. These results suggest that MAK-1 is an activator of twitchin kinase and that the p38 MAP kinase pathway may be involved in the regulation of twitchin.
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Affiliation(s)
- Yohei Matsunaga
- Department of Pathology, Emory University, Atlanta, GA 30322
| | - Hiroshi Qadota
- Department of Pathology, Emory University, Atlanta, GA 30322
| | - Miho Furukawa
- Department of Pathology, Emory University, Atlanta, GA 30322
| | | | - Guy M Benian
- Department of Pathology, Emory University, Atlanta, GA 30322
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26
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Benian GM, Mayans O. Titin and obscurin: giants holding hands and discovery of a new Ig domain subset. J Mol Biol 2014; 427:707-714. [PMID: 25555989 DOI: 10.1016/j.jmb.2014.12.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Guy M Benian
- Department of Pathology, Emory University, Atlanta, GA 30322, USA.
| | - Olga Mayans
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK.
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27
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Qadota H, Luo Y, Matsunaga Y, Park AS, Gernert KM, Benian GM. Suppressor mutations suggest a surface on PAT-4 (Integrin-linked Kinase) that interacts with UNC-112 (Kindlin). J Biol Chem 2014; 289:14252-62. [PMID: 24692564 PMCID: PMC4022890 DOI: 10.1074/jbc.m114.556308] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 03/20/2014] [Indexed: 11/06/2022] Open
Abstract
Caenorhabditis elegans striated muscle cells attach to basement membrane and transmit the force of muscle contraction through integrin adhesion complexes. The cytoplasmic tail of β-integrin (PAT-3) is associated with a conserved four-protein complex that includes UNC-112 (kindlin), PAT-4 (integrin-linked kinase), PAT-6 (α-parvin/actopaxin), and UNC-97 (PINCH). The proper localization of UNC-112 to muscle integrin adhesion sites requires PAT-4. A recent report (Qadota, H., Moerman, D. G., and Benian, G. M. (2012) A molecular mechanism for the requirement of PAT-4 (integrin-linked kinase (ILK)) for the localization of UNC-112 (kindlin) to integrin adhesion sites. J. Biol. Chem. 287, 28537-28551) suggests a possible molecular mechanism for this requirement: that UNC-112 exists in closed inactive and open active conformations, and conversion to the open active form is promoted by binding to PAT-4 (ILK). Previously, we also reported identification of a single missense mutation in UNC-112, D382V, which abolishes both binding to PAT-4 and normal localization to integrin adhesion sites in vivo. In this report, we describe isolation and characterization of PAT-4 missense mutations that permit binding with UNC-112 D382V and place nine affected residues on a homology model of PAT-4. These nine residues cluster in two regions on the surface of PAT-4, do not overlap the likely binding surface for PAT-6 (α-parvin), and therefore may reside along the interaction surface of PAT-4 for UNC-112 (kindlin). We also show that one of these PAT-4 mutations restores the ability of UNC-112 D382V to localize to integrin adhesions and participate in complex formation.
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Affiliation(s)
- Hiroshi Qadota
- From the Department of Pathology, Emory University, Atlanta, Georgia 30322 and
| | - Yating Luo
- From the Department of Pathology, Emory University, Atlanta, Georgia 30322 and
| | - Yohei Matsunaga
- From the Department of Pathology, Emory University, Atlanta, Georgia 30322 and
| | - Angela S Park
- From the Department of Pathology, Emory University, Atlanta, Georgia 30322 and
| | - Kim M Gernert
- the Biomolecular Computing Resource, Emory University, Atlanta, Georgia 30322
| | - Guy M Benian
- From the Department of Pathology, Emory University, Atlanta, Georgia 30322 and
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28
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Qadota H, Benian GM. An approach for exploring interaction between two proteins in vivo. Front Physiol 2014; 5:162. [PMID: 24808865 PMCID: PMC4010775 DOI: 10.3389/fphys.2014.00162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 04/08/2014] [Indexed: 01/13/2023] Open
Abstract
We describe a strategy for exploring the function of protein-protein interactions in striated muscle in vivo. We describe our experience using this strategy to study the interaction of UNC-112 (kindlin) with PAT-4 (integrin linked kinase). Random mutagenesis is used to generate a collection of mutants that are screened for lack of binding or gain of binding using a yeast 2-hybrid assay. The mutant proteins are then expressed in transgenic C. elegans to determine their ability to localize in the sarcomere. We emphasize two advantages of this strategy: (1) for studying the interaction of protein A with protein B, when protein A can interact with multiple proteins, and (2) it explores the function of an interaction rather than the absence of, or reduced level of, a protein as can be obtained with null mutants or knockdown by RNAi. We propose that this method can be generalized for studying the meaning of a protein-protein interaction in muscle for any system in which transgenic animals can be generated and their muscles can be imaged.
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Affiliation(s)
- Hiroshi Qadota
- Department of Pathology, Emory University Atlanta, GA, USA
| | - Guy M Benian
- Department of Pathology, Emory University Atlanta, GA, USA
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Abstract
Giant muscle proteins (e.g., titin, nebulin, and obscurin) play a seminal role in muscle elasticity, stretch response, and sarcomeric organization. Each giant protein consists of multiple tandem structural domains, usually arranged in a modular fashion spanning 500 kDa to 4 MDa. Although many of the domains are similar in structure, subtle differences create a unique function of each domain. Recent high and low resolution structural and dynamic studies now suggest more nuanced overall protein structures than previously realized. These findings show that atomic structure, interactions between tandem domains, and intrasarcomeric environment all influence the shape, motion, and therefore function of giant proteins. In this article we will review the current understanding of titin, obscurin, and nebulin structure, from the atomic level through the molecular level.
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Affiliation(s)
- Logan C Meyer
- Department of Chemistry and Biochemistry, James Madison University Harrisonburg, VA, USA
| | - Nathan T Wright
- Department of Chemistry and Biochemistry, James Madison University Harrisonburg, VA, USA
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30
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Mechanistic and functional diversity in the mechanosensory kinases of the titin-like family. Biochem Soc Trans 2013; 41:1066-71. [DOI: 10.1042/bst20130085] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The giant cytoskeletal kinases of the titin-like family are emerging as key mediators of stretch-sensing in muscle. It is thought that their elastic conformational deformation during muscle function regulates both their catalysis and the recruitment of regulatory proteins to signalosomes that assemble in their vicinity. In the present article, we discuss the speciation of mechanosensory mechanisms in titin-like kinases, their scaffolding properties and the kinase/pseudokinase domain variations that define a rich functional diversity across the family.
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Perry NA, Ackermann MA, Shriver M, Hu LYR, Kontrogianni-Konstantopoulos A. Obscurins: unassuming giants enter the spotlight. IUBMB Life 2013; 65:479-86. [PMID: 23512348 DOI: 10.1002/iub.1157] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 01/31/2013] [Indexed: 02/04/2023]
Abstract
Discovered about a decade ago, obscurin (~720 kDa) is a member of a family of giant proteins expressed in striated muscle that are essential for normal muscle function. Much of what we understand about obscurin stems from its functions in cardiac and skeletal muscle. However, recent evidence has indicated that variants of obscurin ("obscurins") are expressed in diverse cell types, where they contribute to distinct cellular processes. Dysfunction or abrogation of obscurins has also been implicated in the development of several pathological conditions, including cardiac hypertrophy and cancer. Herein, we present an overview of obscurins with an emphasis on novel findings that demonstrate their heretofore-unsuspected importance in cell signaling and disease progression.
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Affiliation(s)
- Nicole A Perry
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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