Calcium regulation of non-kinase and kinase activities of recombinant myosin light-chain kinase and its mutants.
IUBMB Life
; 61(11): 1092-8, 2009 Nov.
Article
em En
| MEDLINE
| ID: mdl-19859981
ABSTRACT
Myosin light-chain kinase (MLCK) comprised of N-terminal actin-binding domain, central catalytic domain, and C-terminal myosin-binding domain. It exerted not only kinase activity to phosphorylate 20 kDa regulatory light chain of smooth muscle but also exerted non-kinase activity on myosin motor and myosin ATPase activities (Nakamura et al., Biochem. Biophys. Res. Commun. 2008, 369, 135). The previous studies on the multiple MLCK functions were done using MLCK fragments. The present study reported the expression of whole MLCK molecules in Escherichia coli in a large amount. The construct in which the calmodulin (CaM) binding domain for regulating kinase activity was mutated lost the kinase activity. However, the mutant exerted non-kinase activity and inhibited both myosin motor and ATPase activities. The domain that regulated kinase activity was also shown to be involved in the Ca(2+) regulation of non-kinase activity. The deletion mutants of actin-binding domain which located at N-terminal 1-41 amino acids demonstrated that non-kinase activity was mediated through actin filaments.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Quinase de Cadeia Leve de Miosina
/
Cálcio
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article