Phosphorylation by Protein Kinase C of a 20-kDa Cytoskeletal Polypeptide Enhances Its Susceptibility to Digestion by Calpain
Overview
Affiliations
Incubation of the cytoskeletal fraction from human neutrophils with the proteolytically activated form of protein kinase C results in the phosphorylation of several components, including a 20-kDa polypeptide, probably consisting of myosin light chains. The 20-kDa polypeptide is also specifically phosphorylated by activated protein kinase C in a solubilized 20-kDa/80-kDa complex that was obtained after sonication of the insoluble cytoskeletal fraction. Phosphorylation of this polypeptide, in either the insoluble cytoskeletal fraction or the soluble 20-kDa/80-kDa complex, greatly enhances its susceptibility to digestion by the Ca2+-requiring proteinase (calpain, EC 3.4.22.17) of human neutrophils. Thus, signals that activate calpain by mobilizing intracellular calcium would lead to proteolytic activation of protein kinase C, phosphorylation of cytoskeletal proteins, and remodeling of the cytoskeleton by proteolysis of at least one cytoskeletal component.
PEST sequences in calmodulin-binding proteins.
Barnes J, Gomes A Mol Cell Biochem. 1995; 149-150:17-27.
PMID: 8569726 DOI: 10.1007/BF01076559.
Regulation of the phosphorylation of calpain II and its inhibitor.
Kuo W, Ganesan U, Davis D, Walbey D Mol Cell Biochem. 1994; 136(2):157-61.
PMID: 7845369 DOI: 10.1007/BF00926076.
Pontremoli S, Melloni E, Michetti M, Sparatore B, Salamino F, Sacco O Proc Natl Acad Sci U S A. 1987; 84(11):3604-8.
PMID: 3473471 PMC: 304923. DOI: 10.1073/pnas.84.11.3604.
The human gastrin precursor. Characterization of phosphorylated forms and fragments.
Varro A, Desmond H, Pauwels S, Gregory H, Young J, Dockray G Biochem J. 1988; 256(3):951-7.
PMID: 3223964 PMC: 1135508. DOI: 10.1042/bj2560951.
The role of protein phosphorylation in the control of cell growth and differentiation.
Lord J, Bunce C, Brown G Br J Cancer. 1988; 58(5):549-55.
PMID: 3064796 PMC: 2246823. DOI: 10.1038/bjc.1988.256.