R. Williams et Lm. Coluccio, PHOSPHORYLATION OF MYOSIN-I FROM RAT-LIVER BY PROTEIN-KINASE-C REDUCES CALMODULIN-BINDING, Biochemical and biophysical research communications, 216(1), 1995, pp. 90-102
Three isoforms of the cytoskeletal-associated, mechanochemical enzymes
known as myosin-I have been purified from rat liver; each coisolates
with calmodulin. Incubation of the purified myosin-I's with protein ki
nase C gamma and P-32- ATP results in phosphorylation of the myosin-I
heavy chains. After phosphorylation, the myosin-I isoforms bind less r
adiolabeled calmodulin in binding assays than observed for control sam
ples. Since the purified isoforms are phosphoproteins as determined by
immunoblotting with monoclonal antibodies which recognize phosphoamin
o acids, these results indicate that phosphorylation might play a role
in regulation of myosin-I. (C) 1995 Academic Press, Inc.