The carboxyl terminus of the smooth muscle myosin light chain kinase is expressed as an independent protein, telokin

• Published in: The Journal of biological chemistry 1991-12, Vol.266 (35), p.23945-23952
• Main Authors: GALLAGHER, P. J, HERRING, B. P
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Analytical, structural and metabolic biochemistry; Animals; Antibodies; Base Sequence; Biological and medical sciences; C-terminus; cDNA; DNA - genetics; DNA - isolation & purification; Electrophoresis, Polyacrylamide Gel; Enzymes and enzyme inhibitors; Female; Fundamental and applied biological sciences. Psychology; genes; Genomic Library; Molecular Sequence Data; Molecular Weight; Muscle Proteins - genetics; Muscle Proteins - isolation & purification; Muscle, Smooth - enzymology; myosin light chain kinase; Myosin-Light-Chain Kinase - genetics; nucleotide sequence; Peptide Fragments; Peptides; predictions; Rabbits; Restriction Mapping; smooth muscle; telokin; Transferases; Uterus - enzymology
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/s0021-9258(18)54376-3

It has been proposed that the carboxyl terminus of the smooth muscle myosin light chain kinase is expressed as an independent protein. This protein has been purified from tissues and named telokin (Ito, M., Dabrowska, R., Guerriero, V., Jr., and Hartshorne, D. J. (1989) J. Biol. Chem. 264, 13971-13974). In this study we have isolated and characterized cDNA and genomic clones encoding telokin. Analysis of a genomic DNA clone suggests that the mRNA encoding telokin arises from a promoter which appears to be located within an intron of the smooth muscle myosin light chain kinase (MLCK) gene. This intron interrupts exons encoding the calmodulin binding domain of the kinase. The amino acid sequence deduced from the cDNA predicts that telokin is identical to the carboxyl-terminal 155 residues of the smooth muscle MLCK. Unlike the smooth muscle MLCK which is expressed in both smooth and non-muscle tissues, telokin is expressed in some smooth muscle tissues but has not been detected in aortic smooth muscle or in any non-muscle tissues.