Unique sequence of a high molecular weight myosin light chain kinase is involved in interaction with actin cytoskeleton

• Published in: FEBS letters Vol. 463; no. 1; pp. 67 - 71
• Main Authors: Kudryashov, Dmitry S., Chibalina, Margarita V., Birukov, Konstantin G., Lukas, Thomas J., Sellers, James R., Van Eldik, Linda J., Watterson, D.Martin, Shirinsky, Vladimir P.
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 10.12.1999
• Subjects: Actin Cytoskeleton - metabolism; Actins - metabolism; Animals; Binding Sites; Calmodulin; CaM, calmodulin; Cells, Cultured; Chickens; Cytoskeleton; Cytoskeleton - metabolism; GFP, green fluorescent protein; Green Fluorescent Proteins; HeLa Cells; HMM, heavy meromyosin; Humans; KRP, kinase-related protein; Luminescent Proteins - metabolism; Microfilament; MLCK, myosin light chain kinase; Molecular Weight; Muscle, Smooth, Vascular - enzymology; Myosin light chain kinase; Myosin-Light-Chain Kinase - chemistry; Myosin-Light-Chain Kinase - metabolism; PMSF, phenylmethylsulfonylfluoride; Protein Isoforms; Rabbits; RLC, M r 20 kDa regulatory light chain; SMM, smooth muscle myosin; Turkeys; GFP, green fluorescent protein; SMM, smooth muscle myosin; HMM, heavy meromyosin; KRP, kinase-related protein; Myosin light chain kinase; PMSF, phenylmethylsulfonylfluoride; Microfilament; Cytoskeleton; CaM, calmodulin; MLCK, myosin light chain kinase; RLC, M r 20 kDa regulatory light chain; Calmodulin
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/S0014-5793(99)01591-4

Myosin light chain kinase (MLCK) is the key regulator of cell motility and smooth muscle contraction in higher vertebrates. We searched for the features of the high molecular weight MLCK (MLCK-210) associated with its unique N-terminal sequence not found in a more ubiquitous lower molecular weight MLCK (MLCK-108). MLCK-210 demonstrates stronger association with the Triton-insoluble cytoskeletons than MLCK-108, suggesting the role for this sequence in subcellular targeting. Indeed, the expressed unique domain of MLCK-210 binds and bundles F-actin in vitro and colocalises with the microfilaments in transfected cells reproducing endogenous MLCK-210 distribution. Thus, MLCK-210 features an extensive actin binding interface and, perhaps, acts as an actin cytoskeleton stabiliser.