scholarly journals Spaceflight results in increase of thick filament but not thin filament proteins in the paramyosin mutant of Caenorhabditis elegans

2008 ◽  
Vol 41 (5) ◽  
pp. 816-823 ◽  
Author(s):  
R. Adachi ◽  
T. Takaya ◽  
K. Kuriyama ◽  
A. Higashibata ◽  
N. Ishioka ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Thin Filament ◽  
Thick Filament ◽  
Thin Filament Proteins

scholarly journals Ubiquitylation by Trim32 causes coupled loss of desmin, Z-bands, and thin filaments in muscle atrophy

2012 ◽  
Vol 198 (4) ◽  
pp. 575-589 ◽  
Author(s):  
Shenhav Cohen ◽  
Bo Zhai ◽  
Steven P. Gygi ◽  
Alfred L. Goldberg
Keyword(s):  
Muscle Atrophy ◽  
Ubiquitin Ligase ◽  
Thin Filament ◽  
Thick Filament ◽  
Myofibrillar Proteins ◽  
Rapid Loss ◽  
Thin Filaments ◽  
Thin Filament Proteins ◽  
Rapid Destruction ◽  
Fiber Atrophy

During muscle atrophy, myofibrillar proteins are degraded in an ordered process in which MuRF1 catalyzes ubiquitylation of thick filament components (Cohen et al. 2009. J. Cell Biol. http://dx.doi.org/10.1083/jcb.200901052). Here, we show that another ubiquitin ligase, Trim32, ubiquitylates thin filament (actin, tropomyosin, troponins) and Z-band (α-actinin) components and promotes their degradation. Down-regulation of Trim32 during fasting reduced fiber atrophy and the rapid loss of thin filaments. Desmin filaments were proposed to maintain the integrity of thin filaments. Accordingly, we find that the rapid destruction of thin filament proteins upon fasting was accompanied by increased phosphorylation of desmin filaments, which promoted desmin ubiquitylation by Trim32 and degradation. Reducing Trim32 levels prevented the loss of both desmin and thin filament proteins. Furthermore, overexpression of an inhibitor of desmin polymerization induced disassembly of desmin filaments and destruction of thin filament components. Thus, during fasting, desmin phosphorylation increases and enhances Trim32-mediated degradation of the desmin cytoskeleton, which appears to facilitate the breakdown of Z-bands and thin filaments.

scholarly journals A Region of the Myosin Rod Important for Interaction With Paramyosin in Caenorhabditis elegans Striated Muscle

Genetics ◽  
2000 ◽  
Vol 156 (2) ◽  
pp. 631-643
Author(s):  
Pamela E Hoppe ◽  
Robert H Waterston
Keyword(s):  
Caenorhabditis Elegans ◽  
Heavy Chain ◽  
Molecular Interaction ◽  
Striated Muscle ◽  
Genetic Interaction ◽  
Specific Interaction ◽  
Thick Filament ◽  
Parallel Arrangement ◽  
Myosin Rod

Abstract The precise arrangement of molecules within the thick filament, as well as the mechanisms by which this arrangement is specified, remains unclear. In this article, we have exploited a unique genetic interaction between one isoform of myosin heavy chain (MHC) and paramyosin in Caenorhabditis elegans to probe the molecular interaction between MHC and paramyosin in vivo. Using chimeric myosin constructs, we have defined a 322-residue region of the MHC A rod critical for suppression of the structural and motility defects associated with the unc-15(e73) allele. Chimeric constructs lacking this region of MHC A either fail to suppress, or act as dominant enhancers of, the e73 phenotype. Although the 322-residue region is required for suppression activity, our data suggest that sequences along the length of the rod also play a role in the isoform-specific interaction between MHC A and paramyosin. Our genetic and cell biological analyses of construct behavior suggest that the 322-residue region of MHC A is important for thick filament stability. We present a model in which this region mediates an avid interaction between MHC A and paramyosin in parallel arrangement in formation of the filament arms.

scholarly journals KLHL40 deficiency destabilizes thin filament proteins and promotes nemaline myopathy

2014 ◽  
Vol 124 (8) ◽  
pp. 3529-3539 ◽  
Author(s):  
Ankit Garg ◽  
Jason O’Rourke ◽  
Chengzu Long ◽  
Jonathan Doering ◽  
Gianina Ravenscroft ◽  
...  
Keyword(s):  
Thin Filament ◽  
Nemaline Myopathy ◽  
Thin Filament Proteins

Expression of Fast Thin Filament Proteins. Defining Fiber Archetypes in a Molecular Continuum

1990 ◽  
pp. 279-292 ◽  
Author(s):  
Fred Schachat ◽  
Margaret M. Briggs ◽  
Edward K. Williamson ◽  
Hirschel McGinnis ◽  
Michael S. Diamond ◽  
...  
Keyword(s):  
Thin Filament ◽  
Thin Filament Proteins

scholarly journals INTRINSIC BIREFRINGENCE OF GLYCERINATED MYOFIBRILS

1971 ◽  
Vol 51 (3) ◽  
pp. 763-771 ◽  
Author(s):  
Richard H. Colby
Keyword(s):  
Thin Filament ◽  
Striated Muscle ◽  
Thick Filament ◽  
Weight Basis ◽  
Macromolecular Structure ◽  
Form Birefringence ◽  
Sliding Filament Theory ◽  
Filament Protein ◽  
Formalin Fixed ◽  
Intrinsic Birefringence

Patterns of intrinsic birefringence were revealed in formalin-fixed, glycerinated myofibrils from rabbit striated muscle, by perfusing them with solvents of refractive index near to that of protein, about 1.570. The patterns differ substantially from those obtained in physiological salt solutions, due to the elimination of edge- and form birefringence. Analysis of myofibrils at various stages of shortening has produced results fully consistent with the sliding filament theory of contraction. On a weight basis, the intrinsic birefringence of thick-filament protein is about 2.4 times that of thin-filament protein. Nonadditivity of thick- and thin-filament birefringence in the overlap regions of A bands may indicate an alteration of macromolecular structure due to interaction between the two types of filaments.

scholarly journals Specific Myosin Heavy Chain Mutations Suppress Troponin I Defects in Drosophila Muscles

1999 ◽  
Vol 144 (5) ◽  
pp. 989-1000 ◽  
Author(s):  
William A. Kronert ◽  
Angel Acebes ◽  
Alberto Ferrús ◽  
Sanford I. Bernstein
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Thin Filament ◽  
Troponin I ◽  
Point Mutations ◽  
Thick Filament ◽  
Actin Binding ◽  
Filament Protein ◽  
Phenotypic Rescue

We show that specific mutations in the head of the thick filament molecule myosin heavy chain prevent a degenerative muscle syndrome resulting from the hdp2 mutation in the thin filament protein troponin I. One mutation deletes eight residues from the actin binding loop of myosin, while a second affects a residue at the base of this loop. Two other mutations affect amino acids near the site of nucleotide entry and exit in the motor domain. We document the degree of phenotypic rescue each suppressor permits and show that other point mutations in myosin, as well as null mutations, fail to suppress the hdp2 phenotype. We discuss mechanisms by which the hdp2 phenotypes are suppressed and conclude that the specific residues we identified in myosin are important in regulating thick and thin filament interactions. This in vivo approach to dissecting the contractile cycle defines novel molecular processes that may be difficult to uncover by biochemical and structural analysis. Our study illustrates how expression of genetic defects are dependent upon genetic background, and therefore could have implications for understanding gene interactions in human disease.

scholarly journals Myosin-18B Regulates Higher-Order Organization of the Cardiac Sarcomere through Thin Filament Cross-Linking and Thick Filament Dynamics

Cell Reports ◽  
2020 ◽  
Vol 32 (9) ◽  
pp. 108090
Author(s):  
Sharissa L. Latham ◽  
Nadine Weiß ◽  
Kristin Schwanke ◽  
Claudia Thiel ◽  
David R. Croucher ◽  
...  
Keyword(s):  
Thin Filament ◽  
Thick Filament ◽  
Higher Order ◽  
Cross Linking ◽  
Cardiac Sarcomere ◽  
Filament Dynamics

Pig platelet tropomyosin: Interactions with the other thin-filament proteins

1986 ◽  
Vol 192 (4) ◽  
pp. 815-830 ◽  
Author(s):  
G. Pruliere ◽  
S.D. Fuller ◽  
A.G. Weeds ◽  
A. d'Albis ◽  
E. der Terrossian
Keyword(s):  
Thin Filament ◽  
The Other ◽  
Thin Filament Proteins

Doxorubicin and covalently crosslinked doxorubicin derivatives binding to purified cardiac thin-filament proteins in vitro

1985 ◽  
Vol 43 (1) ◽  
pp. 64-73 ◽  
Author(s):  
William Lewis ◽  
Kevin Beckenstein ◽  
Lawrence Shapiro ◽  
Saul Puszkin
Keyword(s):  
Thin Filament ◽  
Thin Filament Proteins

scholarly journals The UNC-45 chaperone mediates sarcomere assembly through myosin degradation in Caenorhabditis elegans

2007 ◽  
Vol 177 (2) ◽  
pp. 205-210 ◽  
Author(s):  
Megan L. Landsverk ◽  
Shumin Li ◽  
Alex H. Hutagalung ◽  
Ayaz Najafov ◽  
Thorsten Hoppe ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Proteasome Inhibition ◽  
Thick Filament ◽  
Ubiquitin Proteasome System ◽  
Loss Of Function ◽  
Cellular Processes ◽  
Ubiquitin Proteasome ◽  
Myosin Motors ◽  
And Function ◽  
Sarcomere Assembly

Myosin motors are central to diverse cellular processes in eukaryotes. Homologues of the myosin chaperone UNC-45 have been implicated in the assembly and function of myosin-containing structures in organisms from fungi to humans. In muscle, the assembly of sarcomeric myosin is regulated to produce stable, uniform thick filaments. Loss-of-function mutations in Caenorhabditis elegans UNC-45 lead to decreased muscle myosin accumulation and defective thick filament assembly, resulting in paralyzed animals. We report that transgenic worms overexpressing UNC-45 also display defects in myosin assembly, with decreased myosin content and a mild paralysis phenotype. We find that the reduced myosin accumulation is the result of degradation through the ubiquitin/proteasome system. Partial proteasome inhibition is able to restore myosin protein and worm motility to nearly wild-type levels. These findings suggest a mechanism in which UNC-45–related proteins may contribute to the degradation of myosin in conditions such as heart failure and muscle wasting.

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