scholarly journals Filament assembly properties of the sarcomeric myosin heavy chain

1999 ◽  
Vol 78 (5) ◽  
pp. 735-742 ◽  
Author(s):  
M Wick
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Filament Assembly

Dictyostelium myosin heavy chain phosphorylation sites regulate myosin filament assembly and localization in vivo

Cell ◽  
1993 ◽  
Vol 75 (2) ◽  
pp. 363-371 ◽  
Author(s):  
Thomas T. Egelhoff ◽  
Randall J. Lee ◽  
James A. Spudich
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Myosin Filament ◽  
Phosphorylation Sites ◽  
Filament Assembly ◽  
Dictyostelium Myosin

scholarly journals Caenorhabditis elegans Unc-45 Is a Component of Muscle Thick Filaments and Colocalizes with Myosin Heavy Chain B, but Not Myosin Heavy Chain a

2000 ◽  
Vol 148 (2) ◽  
pp. 375-384 ◽  
Author(s):  
Wanyuan Ao ◽  
Dave Pilgrim
Keyword(s):  
Caenorhabditis Elegans ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Body Wall ◽  
Thick Filament ◽  
The Body ◽  
Temperature Sensitive ◽  
Filament Assembly ◽  
Thick Filaments ◽  
Body Wall Muscles

In the nematode Caenorhabditis elegans, animals mutant in the gene encoding the protein product of the unc-45 gene (UNC-45) have disorganized muscle thick filaments in body wall muscles. Although UNC-45 contains tetratricopeptide repeats (TPR) as well as limited similarity to fungal proteins, no biochemical role has yet been found. UNC-45 reporters are expressed exclusively in muscle cells, and a functional reporter fusion is localized in the body wall muscles in a pattern identical to thick filament A-bands. UNC-45 colocalizes with myosin heavy chain (MHC) B in wild-type worms as well as in temperature-sensitive (ts) unc-45 mutants, but not in a mutant in which MHC B is absent. Surprisingly, UNC-45 localization is also not seen in MHC B mutants, in which the level of MHC A is increased, resulting in near-normal muscle thick filament structure. Thus, filament assembly can be independent of UNC-45. UNC-45 shows a localization pattern identical to and dependent on MHC B and a function that appears to be MHC B–dependent. We propose that UNC-45 is a peripheral component of muscle thick filaments due to its localization with MHC B. The role of UNC-45 in thick filament assembly seems restricted to a cofactor for assembly or stabilization of MHC B.

Molecular genetic truncation analysis of filament assembly and phosphorylation domains of Dictyostelium myosin heavy chain

1994 ◽  
Vol 107 (10) ◽  
pp. 2875-2886 ◽  
Author(s):  
R.J. Lee ◽  
T.T. Egelhoff ◽  
J.A. Spudich
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Molecular Motor ◽  
Molecular Genetic ◽  
Surface Receptors ◽  
Cell Functions ◽  
Filament Assembly ◽  
Carboxy Terminal

Conventional myosin (‘myosin II’) is a major component of the cytoskeleton in a wide variety of eukaryotic cells, ranging from lower amoebae to mammalian fibroblasts and neutrophils. Gene targeting technologies available in the Dictyostelium discoideum system have provided the first genetic proof that this molecular motor protein is essential for normal cytokinesis, capping of cell surface receptors, normal chemotactic cell locomotion and morphogenetic shape changes during development. Although the roles of myosin in a variety of cell functions are becoming clear, the mechanisms that regulate myosin assembly into functional bipolar filaments within cells are poorly understood. Dictyostelium is currently the only system where mutant forms of myosin can be engineered in vitro, then expressed in their native context in cells that are devoid of the wild-type isoform. We have utilized this technology in combination with nested truncation and deletion analysis to map domains of the myosin tail necessary for in vivo and in vitro filament assembly, and for normal myosin heavy chain (MHC) phosphorylation. This analysis defines a region of 35 amino acids within the tail that is critical for filament formation both for purified myosin molecules and for myosin within the in vivo setting. Phosphorylation analysis of these mutants in intact cytoskeletons demonstrates that the carboxy-terminal tip of the myosin heavy chain is required for complete phosphorylation of the myosin tail.

The importance of subfragment 2 and C-terminus of myosin heavy chain for thick filament assembly in skeletal muscle cells

2014 ◽  
Vol 86 (4) ◽  
pp. 459-467 ◽  
Author(s):  
Koichi Ojima ◽  
Mika Oe ◽  
Ikuyo Nakajima ◽  
Masahiro Shibata ◽  
Susumu Muroya ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Muscle Cells ◽  
Thick Filament ◽  
Skeletal Muscle Cells ◽  
Filament Assembly ◽  
C Terminus
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