Isoform-Specific cDNAs for Human Embryonic, Neonatal, and Slow Skeletal Myosin Heavy Chains

• Published in: Annals of the New York Academy of Sciences 1990, Vol.599 (1), p.119-126
• Main Authors: STEDMAN, HANSELL H., KELLY, ALAN M., RUBINSTEIN, NEAL A.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Base Sequence; DNA - genetics; DNA - isolation & purification; Embryo, Mammalian; Gene Library; Humans; Infant, Newborn; Molecular Sequence Data; Muscles - embryology; Muscles - physiology; Myosin Subfragments - genetics; Myosins - genetics; Rats; Restriction Mapping; Sequence Homology, Nucleic Acid
• ISSN: 0077-8923; 1749-6632
• DOI: 10.1111/j.1749-6632.1990.tb42370.x

A series of cDNA fragments encoding immunodetectable portions of the human slow/beta, neonatal, and embryonic isoforms of myosin heavy chain (MHC) were isolated from a human fetal muscle cDNA expression library. A 6 kb fragment isolated on a secondary screen represents the first cloned cDNA encoding a full-length vertebrate MHC (the human embryonic isoform). In the 3'-untranslated regions, 70-80% nucleotide sequence homology exists among orthologous human and rat cDNAs, whereas the homology is less than 65% among the paralogous cDNAs. Furthermore, approximately the same level of untranslated sequence conservation is observed at the 5'-terminus of the embryonic transcript. These results suggest that for both the 3'- and the 5'-untranslated domains, the rate of evolutionary sequence divergence is limited by functional constraints.