High impact information on myo-3

• Because of disrupted MHC A assembly, dominant unc-54 mutants also exhibit a recessive-lethal phenotype [1].
• The mutant MHC B also interferes with assembly of wild-type myosin heavy-chain A (MHC A), the product of another MHC gene expressed in body-wall muscle cells [1].
• Within these regions, MHC A displays a more hydrophobic rod surface, making it more similar to paramyosin, which forms the thick filament core [2].
• Caenorhabditis elegans body wall muscle contains two isoforms of myosin heavy chain, MHC A and MHC B, that differ in their ability to initiate thick filament assembly [2].
• The myo-3 gene mapped to the middle of linkage group V near the cluster of three actin genes (act-1,2,3) [3].

Biological context of myo-3

• We have identified the putative amplification junctions for these sup-3 alleles using a set of cosmid clones which encompass myo-3 region [4].
• Embryos homozygous for deficiencies removing the left tip of chromosome V fail to accumulate the myo-3 and unc-54 products, but express antigens characteristic of hypodermal, pharyngeal and neural development [5].
• Chimeric constructs lacking this region of MHC A either fail to suppress, or act as dominant enhancers of, the e73 phenotype [6].

Other interactions of myo-3

• The nematode Caenorhabditis elegans produces four distinct myosin heavy chain (MHC) isoforms, A, B, C, and D. The MHC A and MHC B proteins are coordinately expressed in the body wall muscle and are incorporated into different regions of a single kind of thick filament [7].

References