Work

Thiophosphorylation of the 130-kDa Subunit Is Associated with a Decreased Activity of Myosin Light Chain Phosphatase in α-Toxin-permeabilized Smooth Muscle

Year: 1995

Type: article

Abstract: Pretreatment of alpha-toxin-permeabilized smooth muscle with ATP gamma S (adenosine 5'-O-(thiotriphosphate)) under conditions resulting in minimal (< 1%) thiophosphorylation of the myosin light chain increases the subsequent calcium sensitivity of force output and myosin light chain phosphorylation. The change in calcium sensitivity results at least in part from a 5-fold decrease in myosin light chain phosphatase activity. One of the few proteins thiophosphorylated under these conditions is the 130-kDa subunit of myosin light chain phosphatase. These results suggest that thiophosphorylation of this subunit leads to a decrease in the activity of the phosphatase, and that phosphorylation and dephosphorylation of the subunit may play a role in regulating myosin light chain phosphatase activity.

Source: Journal of Biological Chemistry

DOI: 10.1074/jbc.270.31.18191

Authors: Laura Trinkle-Mulcahy, Kazuhito Ichikawa, David J. Hartshorne, Marion J. Siegman, Thomas M. Butler

Institutions: Thomas Jefferson University, University of Arizona

Language: English

Topic: Protein Kinase Regulation and GTPase Signaling

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: hybrid

Estimated APC paid: $3,430

Funders: National Institutes of Health, National Heart, Lung, and Blood Institute