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Christophers B, Leahy SN, Soffar DB, von Saucken VE, Broadie K, Baylies MK. Muscle cofilin alters neuromuscular junction postsynaptic development to strengthen functional neurotransmission. Development 2024; 151:dev202558. [PMID: 38869008 PMCID: PMC11266751 DOI: 10.1242/dev.202558] [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: 11/21/2023] [Accepted: 06/05/2024] [Indexed: 06/14/2024]
Abstract
Cofilin, an actin-severing protein, plays key roles in muscle sarcomere addition and maintenance. Our previous work found that Drosophila cofilin (DmCFL) knockdown in muscle causes progressive deterioration of muscle structure and function and produces features seen in nemaline myopathy caused by cofilin mutations. We hypothesized that disruption of actin cytoskeleton dynamics by DmCFL knockdown would impact other aspects of muscle development, and, thus, conducted an RNA-sequencing analysis that unexpectedly revealed upregulated expression of numerous neuromuscular junction (NMJ) genes. We found that DmCFL is enriched in the muscle postsynaptic compartment and that DmCFL muscle knockdown causes F-actin disorganization in this subcellular domain prior to the sarcomere defects observed later in development. Despite NMJ gene expression changes, we found no significant changes in gross presynaptic Bruchpilot active zones or total postsynaptic glutamate receptor levels. However, DmCFL knockdown resulted in mislocalization of GluRIIA class glutamate receptors in more deteriorated muscles and strongly impaired NMJ transmission strength. These findings expand our understanding of the roles of cofilin in muscle to include NMJ structural development and suggest that NMJ defects may contribute to the pathophysiology of nemaline myopathy.
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Affiliation(s)
- Briana Christophers
- Weill Cornell–Rockefeller–Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY 10065, USA
- Biochemistry, Cell & Developmental Biology, and Molecular Biology (BCMB) program, Weill Cornell Graduate School of Medical Sciences, New York, NY 10065, USA
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering, Cancer Center, New York, NY 10065, USA
| | - Shannon N. Leahy
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - David B. Soffar
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering, Cancer Center, New York, NY 10065, USA
| | - Victoria E. von Saucken
- Weill Cornell–Rockefeller–Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY 10065, USA
- Biochemistry, Cell & Developmental Biology, and Molecular Biology (BCMB) program, Weill Cornell Graduate School of Medical Sciences, New York, NY 10065, USA
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering, Cancer Center, New York, NY 10065, USA
| | - Kendal Broadie
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
- Kennedy Center for Research on Human Development, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
- Vanderbilt Brain Institute, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - Mary K. Baylies
- Biochemistry, Cell & Developmental Biology, and Molecular Biology (BCMB) program, Weill Cornell Graduate School of Medical Sciences, New York, NY 10065, USA
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering, Cancer Center, New York, NY 10065, USA
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Christophers B, Leahy SN, Soffar DB, von Saucken VE, Broadie K, Baylies MK. Muscle cofilin alters neuromuscular junction postsynaptic development to strengthen functional neurotransmission. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.21.568166. [PMID: 38045306 PMCID: PMC10690168 DOI: 10.1101/2023.11.21.568166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
Cofilin, an actin severing protein, plays critical roles in muscle sarcomere addition and maintenance. Our previous work has shown Drosophila cofilin (DmCFL) knockdown causes progressive deterioration of muscle structure and function and produces features seen in nemaline myopathy (NM) caused by cofilin mutations. We hypothesized that disruption of actin cytoskeleton dynamics by DmCFL knockdown would impact other aspects of muscle development, and, thus, conducted an RNA sequencing analysis which unexpectedly revealed upregulated expression of numerous neuromuscular junction (NMJ) genes. We found that DmCFL is enriched in the muscle postsynaptic compartment and that DmCFL deficiency causes F-actin disorganization in this subcellular domain prior to the sarcomere defects observed later in development. Despite NMJ gene expression changes, we found no significant changes in gross presynaptic Bruchpilot active zones or total postsynaptic glutamate receptor levels. However, DmCFL knockdown results in mislocalization of glutamate receptors containing the GluRIIA subunit in more deteriorated muscles and neurotransmission strength is strongly impaired. These findings expand our understanding of cofilin's roles in muscle to include NMJ structural development and suggest that NMJ defects may contribute to NM pathophysiology.
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Affiliation(s)
- Briana Christophers
- Weill Cornell–Rockefeller–Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY, 10065, USA
- Biochemistry, Cell & Developmental Biology, and Molecular Biology (BCMB) program, Weill Cornell Graduate School of Medical Sciences, New York, NY 10065, USA
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering, Cancer Center, New York, NY 10065, USA
| | - Shannon N. Leahy
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - David B. Soffar
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering, Cancer Center, New York, NY 10065, USA
| | - Victoria E. von Saucken
- Weill Cornell–Rockefeller–Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY, 10065, USA
- Biochemistry, Cell & Developmental Biology, and Molecular Biology (BCMB) program, Weill Cornell Graduate School of Medical Sciences, New York, NY 10065, USA
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering, Cancer Center, New York, NY 10065, USA
| | - Kendal Broadie
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
- Kennedy Center for Research on Human Development, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
- Vanderbilt Brain Institute, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - Mary K. Baylies
- Biochemistry, Cell & Developmental Biology, and Molecular Biology (BCMB) program, Weill Cornell Graduate School of Medical Sciences, New York, NY 10065, USA
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering, Cancer Center, New York, NY 10065, USA
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3
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Wu M, Wu Y, Huang J, Wu Y, Wu H, Jiang B, Zhuang J. Protein expression profile changes of lung tissue in patients with pulmonary hypertension. PeerJ 2020; 8:e8153. [PMID: 32030316 PMCID: PMC6996500 DOI: 10.7717/peerj.8153] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 11/04/2019] [Indexed: 12/17/2022] Open
Abstract
Background Pulmonary hypertension occurs in approximately 1% of the global population, and the prognosis for such patients may be poor. However, the mechanisms underlying the development of this disease remain unclear. Thus, understanding the development of pulmonary hypertension and finding new therapeutic targets and approaches are important for improved clinical outcomes. Methods Lung tissue specimens were collected from six patients with atrial septal defect and pulmonary hypertension (all women, with a mean age of 46.5 ± 4.7 years, and their condition could not be corrected with an internal medical occlusion device) and from nine control patients with lung cancer who underwent lobectomy (six men and three women, with a mean age of 56.7 ± 1.7 years). Isobaric tags for relative and absolute quantitation and liquid chromatography tandem mass spectrometry analyses were used to detect protein expression levels. Results We found 74 significantly upregulated and 88 significantly downregulated differentially expressed proteins between control and pulmonary hypertensive lung tissue specimens. Gene ontology analyses identified the top 20 terms in all three categories, that is, biological process, cellular component, and molecular function. Kyoto Encyclopedia of Genes and Genomes and protein–protein interaction analyses determined the top 10 signaling pathways and found that the six hub proteins associated with the differentially expressed upregulated proteins (PRKAA1, DHPR, ACTB, desmin, ACTG1, and ITGA1) were all involved in hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, and dilated cardiomyopathy. Conclusion Our results identified protein expression profile changes in lung tissue derived from patients with pulmonary hypertension, providing potential new biomarkers for clinical diagnosis and prognosis for patients with pulmonary hypertension and offering candidate protein targets for future therapeutic drug development.
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Affiliation(s)
- Min Wu
- Department of Cardiac Surgery, Guangdong Provincial People's Hospital, Guangzhou City, Guangdong Province, China
| | - Yijin Wu
- Department of Cardiac Surgery, Guangdong Provincial People's Hospital, Guangzhou City, Guangdong Province, China
| | - Jinsong Huang
- Department of Cardiac Surgery, Guangdong Provincial People's Hospital, Guangzhou City, Guangdong Province, China
| | - Yueheng Wu
- Department of Cardiac Surgery, Guangdong Provincial People's Hospital, Guangzhou City, Guangdong Province, China
| | - Hongmei Wu
- Department of Cardiac Surgery, Guangdong Provincial People's Hospital, Guangzhou City, Guangdong Province, China
| | - Benyuan Jiang
- Department of Cardiac Surgery, Guangdong Provincial People's Hospital, Guangzhou City, Guangdong Province, China
| | - Jian Zhuang
- Department of Cardiac Surgery, Guangdong Provincial People's Hospital, Guangzhou City, Guangdong Province, China
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O'Rourke AR, Lindsay A, Tarpey MD, Yuen S, McCourt P, Nelson DM, Perrin BJ, Thomas DD, Spangenburg EE, Lowe DA, Ervasti JM. Impaired muscle relaxation and mitochondrial fission associated with genetic ablation of cytoplasmic actin isoforms. FEBS J 2018; 285:481-500. [PMID: 29265728 DOI: 10.1111/febs.14367] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 11/06/2017] [Accepted: 12/13/2017] [Indexed: 12/28/2022]
Abstract
While α-actin isoforms predominate in adult striated muscle, skeletal muscle-specific knockouts (KOs) of nonmuscle cytoplasmic βcyto - or γcyto -actin each cause a mild, but progressive myopathy effected by an unknown mechanism. Using transmission electron microscopy, we identified morphological abnormalities in both the mitochondria and the sarcoplasmic reticulum (SR) in aged muscle-specific βcyto - and γcyto -actin KO mice. We found βcyto - and γcyto -actin proteins to be enriched in isolated mitochondrial-associated membrane preparations, which represent the interface between mitochondria and sarco-endoplasmic reticulum important in signaling and mitochondrial dynamics. We also measured significantly elongated and interconnected mitochondrial morphologies associated with a significant decrease in mitochondrial fission events in primary mouse embryonic fibroblasts lacking βcyto - and/or γcyto -actin. Interestingly, mitochondrial respiration in muscle was not measurably affected as oxygen consumption was similar in skeletal muscle fibers from 12 month-old muscle-specific βcyto - and γcyto -actin KO mice. Instead, we found that the maximal rate of relaxation after isometric contraction was significantly slowed in muscles of 12-month-old βcyto - and γcyto -actin muscle-specific KO mice. Our data suggest that impaired Ca2+ re-uptake may presage development of the observed SR morphological changes in aged mice while providing a potential pathological mechanism for the observed myopathy.
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Affiliation(s)
- Allison R O'Rourke
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, USA
| | - Angus Lindsay
- Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Michael D Tarpey
- Department of Physiology, East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA
| | - Samantha Yuen
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Preston McCourt
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - D'anna M Nelson
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Benjamin J Perrin
- Department of Biology, Indiana University-Purdue University Indianapolis, IN, USA
| | - David D Thomas
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Espen E Spangenburg
- Department of Physiology, East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA
| | - Dawn A Lowe
- Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN, USA
| | - James M Ervasti
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
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Morioka K, Takano-Ohmuro H. Localizations of γ-Actins in Skin, Hair, Vibrissa, Arrector Pili Muscle and Other Hair Appendages of Developing Rats. Acta Histochem Cytochem 2016; 49:47-65. [PMID: 27222613 PMCID: PMC4858540 DOI: 10.1267/ahc.15031] [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: 10/13/2015] [Accepted: 02/16/2016] [Indexed: 11/22/2022] Open
Abstract
Six isoforms of actins encoded by different genes have been identified in mammals including α-cardiac, α-skeletal, α-smooth muscle (α-SMA), β-cytoplasmic, γ-smooth muscle (γ-SMA), and γ-cytoplasmic actins (γ-CYA). In a previous study we showed the localization of α-SMA and other cytoskeletal proteins in the hairs and their appendages of developing rats (Morioka K., et al. (2011) Acta Histochem. Cytochem. 44, 141–153), and herein we determined the localization of γ type actins in the same tissues and organs by immunohistochemical staining. Our results indicate that the expression of γ-SMA and γ-CYA is suggested to be poor in actively proliferating tissues such as the basal layer of the epidermis and the hair matrix in the hair bulb, and as well as in highly keratinized tissues such as the hair cortex and hair cuticle. In contrast, the expression of γ-actins were high in the spinous layer, granular layer, hair shaft, and inner root sheath, during their active differentiations. In particular, the localization of γ-SMA was very similar to that of α-SMA. It was located not only in the arrector pili muscles and muscles in the dermis, but also in the dermal sheath and in a limited area of the outer root sheath in both the hair and vibrissal follicles. The γ-CYA was suggested to be co-localized with γ-SMA in the dermal sheath, outer root sheath, and arrector pili muscles. Sparsely distributed dermal cells expressed both types of γ-actin. The expression of γ-actins is suggested to undergo dynamic changes according to the proliferation and differentiation of the skin and hair-related cells.
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Affiliation(s)
- Kiyokazu Morioka
- Research Institute of Pharmaceutical Sciences, Musashino University
- The Tokyo Metropolitan Institute of Medical Science
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Abstract
Physical working capacity decreases with age and also in microgravity. Regardless of age, increased physical activity can always improve the physical adaptability of the body, although the mechanisms of this adaptability are unknown. Physical exercise produces various mechanical stimuli in the body, and these stimuli may be essential for cell survival in organisms. The cytoskeleton plays an important role in maintaining cell shape and tension development, and in various molecular and/or cellular organelles involved in cellular trafficking. Both intra and extracellular stimuli send signals through the cytoskeleton to the nucleus and modulate gene expression via an intrinsic property, namely the "dynamic instability" of cytoskeletal proteins. αB-crystallin is an important chaperone for cytoskeletal proteins in muscle cells. Decreases in the levels of αB-crystallin are specifically associated with a marked decrease in muscle mass (atrophy) in a rat hindlimb suspension model that mimics muscle and bone atrophy that occurs in space and increases with passive stretch. Moreover, immunofluorescence data show complete co-localization of αB-crystallin and the tubulin/microtubule system in myoblast cells. This association was further confirmed in biochemical experiments carried out in vitro showing that αB-crystallin acts as a chaperone for heat-denatured tubulin and prevents microtubule disassembly induced by calcium. Physical activity induces the constitutive expression of αB-crystallin, which helps to maintain the homeostasis of cytoskeleton dynamics in response to gravitational forces. This relationship between chaperone expression levels and regulation of cytoskeletal dynamics observed in slow anti-gravitational muscles as well as in mammalian striated muscles, such as those in the heart, diaphragm and tongue, may have been especially essential for human evolution in particular. Elucidation of the intrinsic properties of the tubulin/microtubule and chaperone αB-crystallin protein complex systems is expected to provide valuable information for high-pressure bioscience and gravity health science.
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Affiliation(s)
- Yoriko Atomi
- 204 Research Center for Science and Technology, Tokyo University of Agriculture and Technology, Koganei-shi, Tokyo, 184-8588, Japan,
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Rosado M, Barber CF, Berciu C, Feldman S, Birren SJ, Nicastro D, Goode BL. Critical roles for multiple formins during cardiac myofibril development and repair. Mol Biol Cell 2014; 25:811-27. [PMID: 24430873 PMCID: PMC3952851 DOI: 10.1091/mbc.e13-08-0443] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 11/13/2013] [Accepted: 01/09/2014] [Indexed: 12/31/2022] Open
Abstract
Cardiac and skeletal muscle function depends on the proper formation of myofibrils, which are tandem arrays of highly organized actomyosin contractile units called sarcomeres. How the architecture of these colossal molecular assemblages is established during development and maintained over the lifetime of an animal is poorly understood. We investigate the potential roles in myofibril formation and repair of formin proteins, which are encoded by 15 different genes in mammals. Using quantitative real-time PCR analysis, we find that 13 formins are differentially expressed in mouse hearts during postnatal development. Seven formins immunolocalize to sarcomeres in diverse patterns, suggesting that they have a variety of functional roles. Using RNA interference silencing, we find that the formins mDia2, DAAM1, FMNL1, and FMNL2 are required nonredundantly for myofibrillogenesis. Knockdown phenotypes include global loss of myofibril organization and defective sarcomeric ultrastructure. Finally, our analysis reveals an unanticipated requirement specifically for FMNL1 and FMNL2 in the repair of damaged myofibrils. Together our data reveal an unexpectedly large number of formins, with diverse localization patterns and nonredundant roles, functioning in myofibril development and maintenance, and provide the first evidence of actin assembly factors being required to repair myofibrils.
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MESH Headings
- Actins/genetics
- Actins/metabolism
- Animals
- Animals, Newborn
- Bridged Bicyclo Compounds, Heterocyclic/pharmacology
- Cell Differentiation
- Formins
- Gene Expression Regulation, Developmental
- Heterocyclic Compounds, 4 or More Rings/pharmacology
- Intracellular Signaling Peptides and Proteins/antagonists & inhibitors
- Intracellular Signaling Peptides and Proteins/genetics
- Intracellular Signaling Peptides and Proteins/metabolism
- Mice
- Mice, Inbred C57BL
- Microfilament Proteins/antagonists & inhibitors
- Microfilament Proteins/genetics
- Microfilament Proteins/metabolism
- Microtubule-Associated Proteins/antagonists & inhibitors
- Microtubule-Associated Proteins/genetics
- Microtubule-Associated Proteins/metabolism
- Muscle Development/genetics
- Myocardium/cytology
- Myocardium/metabolism
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/ultrastructure
- NADPH Dehydrogenase/antagonists & inhibitors
- NADPH Dehydrogenase/genetics
- NADPH Dehydrogenase/metabolism
- Primary Cell Culture
- Protein Isoforms/antagonists & inhibitors
- Protein Isoforms/genetics
- Protein Isoforms/metabolism
- RNA, Small Interfering/genetics
- RNA, Small Interfering/metabolism
- Sarcomeres/metabolism
- Sarcomeres/ultrastructure
- Thiazolidines/pharmacology
- Wound Healing/genetics
- rho GTP-Binding Proteins/antagonists & inhibitors
- rho GTP-Binding Proteins/genetics
- rho GTP-Binding Proteins/metabolism
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Affiliation(s)
| | | | - Cristina Berciu
- Biology Department and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02454
| | - Steven Feldman
- Biology Department and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02454
| | - Susan J. Birren
- Biology Department and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02454
| | - Daniela Nicastro
- Biology Department and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02454
| | - Bruce L. Goode
- Biology Department and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02454
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Wang L, Miao J, Li L, Wu D, Zhang Y, Peng Z, Zhang L, Yuan Z, Sun K. Identification of an FHL1 protein complex containing gamma-actin and non-muscle myosin IIB by analysis of protein-protein interactions. PLoS One 2013; 8:e79551. [PMID: 24265776 PMCID: PMC3827166 DOI: 10.1371/journal.pone.0079551] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 09/24/2013] [Indexed: 12/24/2022] Open
Abstract
FHL1 is multifunctional and serves as a modular protein binding interface to mediate protein-protein interactions. In skeletal muscle, FHL1 is involved in sarcomere assembly, differentiation, growth, and biomechanical stress. Muscle abnormalities may play a major role in congenital clubfoot (CCF) deformity during fetal development. Thus, identifying the interactions of FHL1 could provide important new insights into its functional role in both skeletal muscle development and CCF pathogenesis. Using proteins derived from rat L6GNR4 myoblastocytes, we detected FHL1 interacting proteins by immunoprecipitation. Samples were analyzed by liquid chromatography mass spectrometry (LC-MS). Dynamic gene expression of FHL1 was studied. Additionally, the expression of the possible interacting proteins gamma-actin and non-muscle myosin IIB, which were isolated from the lower limbs of E14, E15, E17, E18, E20 rat embryos or from adult skeletal muscle was analyzed. Potential interacting proteins isolated from E17 lower limbs were verified by immunoprecipitation, and co-localization in adult gastrocnemius muscle was visualized by fluorescence microscopy. FHL1 expression was associated with skeletal muscle differentiation. E17 was found to be the critical time-point for skeletal muscle differentiation in the lower limbs of rat embryos. We also identified gamma-actin and non-muscle myosin IIB as potential binding partners of FHL1, and both were expressed in adult skeletal muscle. We then demonstrated that FHL1 exists as part of a complex, which binds gamma-actin and non-muscle myosin IIB.
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Affiliation(s)
- Lili Wang
- Key Laboratory of Health Ministry for Congenital Malformation, Shengjing Hospital, China Medical University, Shenyang, China
- * E-mail:
| | - Jianing Miao
- Key Laboratory of Health Ministry for Congenital Malformation, Shengjing Hospital, China Medical University, Shenyang, China
| | - Lianyong Li
- Department of Pediatric Surgery, Shengjing Hospital, China Medical University, Shenyang, China
| | - Di Wu
- Key Laboratory of Health Ministry for Congenital Malformation, Shengjing Hospital, China Medical University, Shenyang, China
| | - Yi Zhang
- Key Laboratory of Health Ministry for Congenital Malformation, Shengjing Hospital, China Medical University, Shenyang, China
| | - Zhaohong Peng
- Key Laboratory of Health Ministry for Congenital Malformation, Shengjing Hospital, China Medical University, Shenyang, China
| | - Lijun Zhang
- Department of Pediatric Surgery, Shengjing Hospital, China Medical University, Shenyang, China
| | - Zhengwei Yuan
- Key Laboratory of Health Ministry for Congenital Malformation, Shengjing Hospital, China Medical University, Shenyang, China
| | - Kailai Sun
- Department of Medical Genetics, China Medical University, Shenyang, China
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Fujita M, Mitsuhashi H, Isogai S, Nakata T, Kawakami A, Nonaka I, Noguchi S, Hayashi YK, Nishino I, Kudo A. Filamin C plays an essential role in the maintenance of the structural integrity of cardiac and skeletal muscles, revealed by the medaka mutant zacro. Dev Biol 2011; 361:79-89. [PMID: 22020047 DOI: 10.1016/j.ydbio.2011.10.008] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Revised: 10/05/2011] [Accepted: 10/06/2011] [Indexed: 12/15/2022]
Abstract
Filamin C is an actin-crosslinking protein that is specifically expressed in cardiac and skeletal muscles. Although mutations in the filamin C gene cause human myopathy with cardiac involvement, the function of filamin C in vivo is not yet fully understood. Here we report a medaka mutant, zacro (zac), that displayed an enlarged heart, caused by rupture of the myocardiac wall, and progressive skeletal muscle degeneration in late embryonic stages. We identified zac to be a homozygous nonsense mutation in the filamin C (flnc) gene. The medaka filamin C protein was found to be localized at myotendinous junctions, sarcolemma, and Z-disks in skeletal muscle, and at intercalated disks in the heart. zac embryos showed prominent myofibrillar degeneration at myotendinous junctions, detachment of myofibrils from sarcolemma and intercalated disks, and focal Z-disk destruction. Importantly, the expression of γ-actin, which we observed to have a strong subcellular localization at myotendinous junctions, was specifically reduced in zac mutant myotomes. Inhibition of muscle contraction by anesthesia alleviated muscle degeneration in the zac mutant. These results suggest that filamin C plays an indispensable role in the maintenance of the structural integrity of cardiac and skeletal muscles for support against mechanical stress.
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Affiliation(s)
- Misato Fujita
- Department of Biological Information, Tokyo Institute of Technology, 4259-B-33 Nagatsuta, Yokohama 226-8501, Japan
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10
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Abstract
Although actin is often thought of as a single protein, in mammals it actually consists of six different isoforms encoded by separate genes. Each isoform is remarkably similar to every other isoform, with only slight variations in amino acid sequence. Nevertheless, recent work indicates that actin isoforms carry out unique cellular functions. Here, we review evidence drawn from localization studies, mouse models, and biochemical characterization to suggest a model for how in vivo mixing of actin isoforms may influence cytoskeletal function in cells. © 2010 Wiley-Liss, Inc.
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Affiliation(s)
- Benjamin J Perrin
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA
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11
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Kee AJ, Gunning PW, Hardeman EC. Diverse roles of the actin cytoskeleton in striated muscle. J Muscle Res Cell Motil 2009; 30:187-97. [PMID: 19997772 DOI: 10.1007/s10974-009-9193-x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2009] [Accepted: 11/24/2009] [Indexed: 12/14/2022]
Abstract
In addition to the highly specialized contractile apparatus, it is becoming increasingly clear that there is an extensive actin cytoskeleton which underpins a wide range of functions in striated muscle. Isoforms of cytoskeletal actin and actin-associated proteins (non-muscle myosins, cytoskeletal tropomyosins, and cytoskeletal alpha-actinins) have been detected in a number of regions of striated muscle: the sub-sarcolemmal costamere, the Z-disc and the T-tubule/sarcoplasmic reticulum membranes. As the only known function of these proteins is through association with actin filaments, their presence in striated muscles indicates that there are spatially and functionally distinct cytoskeletal actin filament systems in these tissues. These filaments are likely to have important roles in mechanical support, ion channel function, myofibrillogenenous and vesicle trafficking.
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Affiliation(s)
- Anthony J Kee
- Department of Anatomy, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
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12
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Jee H, Sakurai T, Kawada S, Ishii N, Atomi Y. Significant roles of microtubules in mature striated muscle deduced from the correlation between tubulin and its molecular chaperone alphaB-crystallin in rat muscles. J Physiol Sci 2009; 59:149-55. [PMID: 19340546 PMCID: PMC10717101 DOI: 10.1007/s12576-008-0014-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2008] [Accepted: 11/23/2008] [Indexed: 11/26/2022]
Abstract
To elucidate the significance of cytoskeletal microtubule networks in striated muscles, we analyzed correlation between the content of tubulin (building block of microtubules) and alphaB-crystallin (a molecular chaperone for tubulin) in a variety of striated muscles expressing different myosin heavy-chain (MHC) isoforms. The content of both tubulin and alphaB-crystallin was larger in MHC-I dominant soleus muscle and in MHC-alpha dominant cardiac (atrium and ventricle) muscles; intermediate in MHC-IId dominant masseter, tongue, and diaphragm muscles; and smaller in MHC-IIb dominant plantaris, gastrocnemius, psoas, extensor digitorum longus, and tibialis anterior muscles. Since the muscles of slow-type MHC (MHC-I/alpha) show the most economical features in their function and metabolism, which suit for continuous activity required to sustain posture and blood pumping, the present results afforded additional support to our hypothesis that microtubule networks transduce mechanical environmental demands to morphological and biochemical responses that eventually evolve adaptive transformation in the function and metabolism of the mature muscles. The comparison of tubulin/alphaB-crystalline ratios across the muscles of varied MHC isoforms further suggested that mechanical stress fluctuating at the rhythmic frequency of walking and breathing efficiently activates the hypothesized dynamic function of microtubules.
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Affiliation(s)
- Hyunseok Jee
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo, 153-8902 Japan
| | - Takashi Sakurai
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo, 153-8902 Japan
| | - Shigeo Kawada
- Department of Human and Engineered Environmental Studies, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba Japan
| | - Naokata Ishii
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo, 153-8902 Japan
| | - Yoriko Atomi
- Integrated Research System for Sustainability Science (IR3S), The University of Tokyo, Faculty of Engineering Bldg.3, Bunkyo-ku, Tokyo, 113-8656 Japan
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13
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Papponen H, Kaisto T, Leinonen S, Kaakinen M, Metsikkö K. Evidence for γ-actin as a Z disc component in skeletal myofibers. Exp Cell Res 2009; 315:218-25. [DOI: 10.1016/j.yexcr.2008.10.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Revised: 09/22/2008] [Accepted: 10/11/2008] [Indexed: 11/16/2022]
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14
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Vlahovich N, Schevzov G, Nair-Shaliker V, Ilkovski B, Artap ST, Joya JE, Kee AJ, North KN, Gunning PW, Hardeman EC. Tropomyosin 4 defines novel filaments in skeletal muscle associated with muscle remodelling/regeneration in normal and diseased muscle. ACTA ACUST UNITED AC 2007; 65:73-85. [PMID: 17968984 DOI: 10.1002/cm.20245] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Nicole Vlahovich
- Muscle Development Unit, Children's Medical Research Institute, Locked Bag 23, Wentworthville, New South Wales 2145, Australia
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15
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Hanft LM, Rybakova IN, Patel JR, Rafael-Fortney JA, Ervasti JM. Cytoplasmic gamma-actin contributes to a compensatory remodeling response in dystrophin-deficient muscle. Proc Natl Acad Sci U S A 2006; 103:5385-90. [PMID: 16565216 PMCID: PMC1459364 DOI: 10.1073/pnas.0600980103] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Dystrophin mechanically links the costameric cytoskeleton and sarcolemma, yet dystrophin-deficient muscle exhibits abnormalities in cell signaling, gene expression, and contractile function that are not clearly understood. We generated new antibodies specific for cytoplasmic gamma-actin and confirmed that gamma-actin most predominantly localized to the sarcolemma and in a faint reticular lattice within normal muscle cells. However, we observed that gamma-actin levels were increased 10-fold at the sarcolemma and within the cytoplasm of striated muscle cells from dystrophin-deficient mdx mice. Transgenic overexpression of the dystrophin homologue utrophin, or functional dystrophin constructs in mdx muscle, restored gamma-actin to normal levels, whereas gamma-actin remained elevated in mdx muscle expressing nonfunctional dystrophin constructs. We conclude that increased cytoplasmic gamma-actin in dystrophin-deficient muscle may be a compensatory response to fortify the weakened costameric lattice through recruitment of parallel mechanical linkages. However, the presence of excessive myoplasmic gamma-actin may also contribute to altered cell signaling or gene expression in dystrophin-deficient muscle.
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Affiliation(s)
- Laurin M. Hanft
- *Department of Physiology, University of Wisconsin, Madison, WI 53706; and
| | - Inna N. Rybakova
- *Department of Physiology, University of Wisconsin, Madison, WI 53706; and
| | | | - Jill A. Rafael-Fortney
- Department of Molecular and Cellular Biochemistry, Ohio State University, Columbus, OH 43210
| | - James M. Ervasti
- *Department of Physiology, University of Wisconsin, Madison, WI 53706; and
- To whom correspondence should be addressed at:
Department of Physiology, University of Wisconsin, 127 Service Memorial Institute, 1300 University Avenue, Madison, WI 53706. E-mail:
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16
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Nissinen M, Kaisto T, Salmela P, Peltonen J, Metsikkö K. Restricted distribution of mRNAs encoding a sarcoplasmic reticulum or transverse tubule protein in skeletal myofibers. J Histochem Cytochem 2005; 53:217-27. [PMID: 15684334 DOI: 10.1369/jhc.4a6431.2005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Calsequestrin (CSQ) and dihydropyridine receptor (DHPR) are muscle cell proteins that are directed into the endoplasmic reticulum (ER) during translation. The former is subsequently found in the sarcoplasmic reticulum (SR) and the latter in the transverse tubule membrane. To elucidate the potential role of mRNA targeting within muscle cells, we have analyzed the localization of CSQ and DHPR proteins and mRNAs in primary cultured rat myotubes, in skeletal muscle cryosections, and in isolated flexor digitorum brevis muscle fibers. In the myotube stage of differentiation, the mRNAs distributed throughout the cell, mimicking the distribution of the endogenous ER marker proteins. In the adult skeletal myofibers, however, both CSQ and DHPRalpha1 transcripts located perinuclearly and in cross-striations flanking Z lines beneath the sarcolemma, a distribution pattern that sharply contrasted the interfibrillar distribution of typical ER proteins. Interestingly, all nuclei of the myofibers were transcriptionally active. In summary, the mRNAs encoding either a resident SR protein or a transverse tubule protein were located beneath the sarcolemma, implying that translocation of the respective proteins to the lumen of ER takes place at this location.
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Affiliation(s)
- Marja Nissinen
- Department of Anatomy and Cell Biology, University of Oulu, Oulu, Finland
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17
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Kee AJ, Schevzov G, Nair-Shalliker V, Robinson CS, Vrhovski B, Ghoddusi M, Qiu MR, Lin JJC, Weinberger R, Gunning PW, Hardeman EC. Sorting of a nonmuscle tropomyosin to a novel cytoskeletal compartment in skeletal muscle results in muscular dystrophy. ACTA ACUST UNITED AC 2004; 166:685-96. [PMID: 15337777 PMCID: PMC2172434 DOI: 10.1083/jcb.200406181] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Tropomyosin (Tm) is a key component of the actin cytoskeleton and >40 isoforms have been described in mammals. In addition to the isoforms in the sarcomere, we now report the existence of two nonsarcomeric (NS) isoforms in skeletal muscle. These isoforms are excluded from the thin filament of the sarcomere and are localized to a novel Z-line adjacent structure. Immunostained cross sections indicate that one Tm defines a Z-line adjacent structure common to all myofibers, whereas the second Tm defines a spatially distinct structure unique to muscles that undergo chronic or repetitive contractions. When a Tm (Tm3) that is normally absent from muscle was expressed in mice it became associated with the Z-line adjacent structure. These mice display a muscular dystrophy and ragged-red fiber phenotype, suggestive of disruption of the membrane-associated cytoskeletal network. Our findings raise the possibility that mutations in these tropomyosin and these structures may underpin these types of myopathies.
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MESH Headings
- Animals
- Cell Compartmentation/genetics
- Cell Membrane/metabolism
- Cell Membrane/pathology
- Cell Membrane/ultrastructure
- Cytoskeleton/metabolism
- Cytoskeleton/pathology
- Cytoskeleton/ultrastructure
- Disease Models, Animal
- Female
- Mice
- Mice, Transgenic
- Muscle Fibers, Skeletal/metabolism
- Muscle Fibers, Skeletal/pathology
- Muscle Fibers, Skeletal/ultrastructure
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/pathology
- Muscle, Skeletal/ultrastructure
- Muscular Dystrophy, Animal/etiology
- Muscular Dystrophy, Animal/metabolism
- Muscular Dystrophy, Animal/physiopathology
- Mutation/genetics
- Phenotype
- Protein Isoforms/genetics
- Protein Isoforms/metabolism
- Protein Isoforms/ultrastructure
- Protein Transport/genetics
- Sarcomeres/metabolism
- Sarcomeres/pathology
- Sarcomeres/ultrastructure
- Tropomyosin/genetics
- Tropomyosin/metabolism
- Tropomyosin/ultrastructure
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Affiliation(s)
- Anthony J Kee
- Muscle Development Unit, Children's Medical Research Institute, Locked Bag 23, Wentworthville, New South Wales 2145, Australia
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18
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Lloyd CM, Berendse M, Lloyd DG, Schevzov G, Grounds MD. A novel role for non-muscle gamma-actin in skeletal muscle sarcomere assembly. Exp Cell Res 2004; 297:82-96. [PMID: 15194427 DOI: 10.1016/j.yexcr.2004.02.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2003] [Revised: 02/13/2004] [Indexed: 11/25/2022]
Abstract
Existing models describing sarcomere assembly have arisen primarily from studies using cardiac muscle. In contrast to cardiac muscle, skeletal muscle differentiation is characterised by dramatic changes in protein expression, from non-muscle to muscle-specific isoforms before organisation of the sarcomeres. Consequently, little is understood of the potential influence of non-muscle cytoskeletal proteins on skeletal sarcomere assembly. To address this issue, transfectant (gamma33-B1) and control mouse C2 myoblasts were differentiated to form myotubes, and various stages of skeletal sarcomere assembly were studied. Organisation of non-muscle gamma-actin and co-localisation with sarcomeric alpha-actinin, an early marker of sarcomere assembly and a major component of Z lines, was noted. gamma-Actin was also identified in young myotubes with developing sarcomeric myofibrils in regenerating adult mouse muscle. Localisation of gamma-actin in a different area of the myotube to the muscle-specific sarcomeric alpha-actin also indicated a distinct role for gamma-actin. The effects of aberrant gamma-actin expression in other myoblast lines, further suggested a sequestering role for gamma-actin. These observations make the novel suggestion that non-muscle gamma-actin plays a role in skeletal sarcomere assembly both in vitro and in vivo. Consequently, a modified model is proposed which describes the role of gamma-actin in skeletal sarcomere assembly.
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Affiliation(s)
- C M Lloyd
- School of Anatomy and Human Biology, The University of Western Australia, Crawley, Western Australia 6009, Australia
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19
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Coghill ID, Brown S, Cottle DL, McGrath MJ, Robinson PA, Nandurkar HH, Dyson JM, Mitchell CA. FHL3 is an actin-binding protein that regulates alpha-actinin-mediated actin bundling: FHL3 localizes to actin stress fibers and enhances cell spreading and stress fiber disassembly. J Biol Chem 2003; 278:24139-52. [PMID: 12704194 DOI: 10.1074/jbc.m213259200] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Four and a half LIM domain (FHL) proteins are members of the LIM protein superfamily. Several FHL proteins function as co-activators of CREM/CREB transcription factors and the androgen receptor. FHL3 is highly expressed in skeletal muscle, but its function is unknown. FHL3 localized to the nucleus in C2C12 myoblasts and, following integrin engagement, exited the nucleus and localized to actin stress fibers and focal adhesions. In mature skeletal muscle FHL3 was found at the Z-line. Actin was identified as a potential FHL3 binding partner in yeast two-hybrid screening of a skeletal muscle library. FHL3 complexed with actin both in vitro and in vivo as shown by glutathione S-transferase pull-down assays and co-immunoprecipitation of recombinant and endogenous proteins. FHL3 promoted cell spreading and when overexpressed in spread C2C12 cells disrupted actin stress fibers. Increased FHL3 expression was detected in highly motile cells migrating into an artificial wound, compared with non-motile cells. The molecular mechanism by which FHL3 induced actin stress fiber disassembly was demonstrated by low speed actin co-sedimentation assays and electron microscopy. FHL3 inhibited alpha-actinin-mediated actin bundling. These studies reveal FHL3 as a significant regulator of actin cytoskeletal dynamics in skeletal myoblasts.
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Affiliation(s)
- Imogen D Coghill
- Department of Biochemistry and Molecular Biology, Monash University, Clayton 3800, Melbourne, Victoria, Australia
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