Premium
Phosphorylation of a tropomyosin‐like (30 KD) protein during platelet activation
Author(s) -
Bourguig Lilly Y. W.,
Field Seth,
Bourguig G. J.
Publication year - 1985
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.240290103
Subject(s) - phosphoprotein , phosphorylation , platelet , tropomyosin , chemistry , protein phosphorylation , platelet activation , protein kinase c , gel electrophoresis , cytoskeleton , polyacrylamide gel electrophoresis , biochemistry , actin , microbiology and biotechnology , protein kinase a , biology , cell , immunology , enzyme
In this study, we have used the tumor promoter 12‐o‐tetradecanoylphorbol‐13‐acetate (TPA), as well as its biologically inactive analogue 4α‐phorbol 12, 13‐didecanoate (4α‐PDD), to investigate platelet protein phosphorylation and its possible correlation with platelet activation. Our data show that TPA, but not 4α‐PDD, induces a preferential phosphorylation of a 30,000 dalton (30 KD) protein. This phosphoprotein is found to be physically associated with an actomyosin‐containing platelet cytoskeleton complex. Further analysis using both standard two‐dimensional gel electrophoresis and one‐dimensional urea‐SDS gel electrophoresis reveals that this 30 KD protein has several tropomyosin‐like properties. Most importantly, the degree of TPA‐induced phosphorylation of the 30 KD protein is directly proportional to the extent of platelet granule release and the shape change of the platelet, as well as to the degree of aggregation. We speculate that this phosphorylated tropomyosinlike protein may play a pivotal role in the regulation of actomyosin‐mediated platelet contractility, which has been previously implicated in a variety of platelet functions.