Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 1984 Nov 15;40(11):1185-8.
doi: 10.1007/BF01946645.

Structure and function of a calmodulin-dependent smooth muscle myosin light chain kinase

G Bailin
Review

Structure and function of a calmodulin-dependent smooth muscle myosin light chain kinase

G Bailin. Experientia. .

Abstract

In smooth muscle the Mr 20,000 light chain of myosin is phosphorylated by a calmodulin-dependent protein kinase. It consists of 2 subunits: calmodulin, an acidic protein of Mr 17,000 that binds 4 moles of Ca2+; and a larger protein of Mr circa 130,000. Activation of the kinase is dependent upon their association in the presence of Ca2+. Cyclic AMP-dependent protein kinase phosphorylation of the myosin light chain kinase occurs at 2 sites. It decreases the affinity of the kinase for calmodulin and a reduction in the rate of light chain phosphorylation occurs. The kinase has an overall asymmetric shape composed of a globular head and tail region for the skeletal muscle enzyme. Trypsin digestion of this kinase releases a fragment of Mr 36,000 from the globular region that contains the catalytic and calmodulin binding sites. Chymotrypsin digestion of the kinase from smooth muscle generates a fragment of Mr 80,000 that does not contain the calmodulin binding or cyclic AMP-dependent protein kinase phosphorylation sites. It is a Ca2+-independent form of the kinase that phosphorylates the light chain of myosin. These structural features indicate a regulatory role for the kinase in smooth muscle phosphorylation and contraction.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

References

    1. FEBS Lett. 1982 Feb 22;138(2):293-8 - PubMed
    1. J Biol Chem. 1980 Sep 25;255(18):8836-41 - PubMed
    1. J Mol Biol. 1983 Mar 25;165(1):139-62 - PubMed
    1. Am J Physiol. 1982 Jan;242(1):C109-16 - PubMed
    1. Fed Proc. 1983 Jan;42(1):45-50 - PubMed

Publication types

MeSH terms

LinkOut - more resources