Rat embryonic fibroblast tropomyosin 1. cDNA and complete primary amino acid sequence.
A cDNA expression library of approximately 80,000 members was prepared from rat embryonic fibroblast mRNA using the plasmid expression vectors pUC8 and pUC9. Using an immunological screening procedure and 32P-labeled cDNA probes, clones encoding rat embryonic fibroblast tropomyosin 1 (TM-1) were identified and isolated. DNA sequence analysis was carried out to determine the amino acid sequence of the protein. Rat embryonic fibroblast TM-1 was found to contain 284 amino acids and is most homologous to smooth muscle alpha-tropomyosin compared with skeletal muscle alpha- and beta-tropomyosins and platelet beta-tropomyosin. Among the various tropomyosins, two regions where the greatest sequence divergence is evident are between amino acids 185 and 216 and amino acids 258 and 284. Rat embryonic fibroblast TM-1 and chicken smooth muscle alpha-tropomyosin are most closely related from amino acids 185 and 216 compared with skeletal muscle and platelet tropomyosins. In contrast, rat embryonic fibroblast TM-1, smooth muscle alpha-tropomyosin, and platelet tropomyosin are most homologous from amino acids 258 and 284 compared with skeletal muscle tropomyosins. These differences in sequences at the carboxyl-terminal region of the various tropomyosins are discussed in relation to differences in their binding to skeletal muscle troponin and its T1 fragment.
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004247:DNA / Q000302:isolation & purification*; D004622:Embryo, Mammalian; D005347:Fibroblasts / Q000378:metabolism; D005822:Genetic Vectors; D009693:Nucleic Acid Hybridization; D010957:Plasmids; D051381:Rats; D014335:Tropomyosin / Q000235:genetics*
D014335:Tropomyosin; D004247:DNA