An unconventional myosin heavy chain gene from Drosophila melanogaster.

摘要: As part of a study cytoskeletal proteins involved in Drosophila embryonic development, we have undertaken the molecular analysis 140-kD ATP-sensitive actin-binding protein (Miller, K. G., C. M. Field, and B. Alberts. 1989. J. Cell Biol. 109:2963-2975). Analysis cDNA clones encoding this revealed that it represents new class unconventional myosin heavy chains. The amino-terminal two thirds comprises head domain is 29-33% identical (60-65% similar) to other heads, contains ATP-binding, calmodulin/myosin light chain-binding motifs. carboxy-terminal tail has no significant similarity known tails, but does contain approximately 100-amino acid region predicted form an alpha-helical coiled-coil. Since unique gene encodes maps polytene map position 95F, named 95F chain (95F MHC). expression profile MHC complex. Examination multiple cDNAs reveals transcripts are alternatively spliced encode at least three isoforms; addition, fourth isoform detected on Western blots. Developmental Northern blots show present throughout life cycle, with peak occurring during mid-embryogenesis adulthood. Immunolocalization early embryos demonstrates primarily located punctate pattern peripheral cytoplasm. Most cells maintain low level embryogenesis, specific tissues appear more protein. We speculate isoforms dynamic processes development.