Open AccessTwo distinct nonmuscle myosin‐heavy‐chain mRNAs are differentially expressed in various chicken tissues
Author(s) -
KATSURAGAWA Yoshinari,
YANAGISAWA Masashi,
INOUE Akihiro,
MASAKI Tomoh
Publication year - 1989
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1989.tb15057.x
Subject(s) - biology , complementary dna , gene isoform , myosin , major histocompatibility complex , skeletal muscle , microbiology and biotechnology , mhc class i , cdna library , gene , genetics , anatomy
Two distinct cDNA clones for nonmuscle myosin heavy chain (MHC) were isolated from a chicken fibroblast cDNA library by cross‐hydridization under a moderate stringency with chicken gizzard smooth muscle MHC cDNA. These two fibroblast MHC and the gizzard MHC are each encoded in different genes in the chicken genome. Northern blot analysis showed that both of the nonmuscle MHC mRNAs were expressed not only in fibroblasts but also in a variety of tissues including brain, lung, kidney, spleen, and skeletal, cardiac and smooth muscles. However, the relative contents of the two nonmuscle MHC mRNAs varied greatly among tissues. The encoded amino acid sequences of the nonmuscle MHCs were highly similar to each other (81% identity) and to the smooth muscle MHC (81–84%), but much less similar to vertebrate skeletal muscle MHCs (38–41%) or to protista nonmuscle MHCs (35–36%). A phylogenic tree of MHC isoforms was constructed by calculating the similarity scores between these MHC sequences. An examination of the tree showed that the vertebrate sarcomeric (skeletal and cardiac) MHC isoforms are encoded in a very closely related multigene family, and that the vertebrate non‐sarcomeric (smooth muscle and nonmuscle) MHC isoforms define a distinct, less conserved MHC gene family.