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Tyrosin dephosphorylation and concurrent inactivation of protein kinase F A /GSK‐3α by genistein in A431 cells
Author(s) -
Yu JauSong,
Yang ShiawDer
Publication year - 1994
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.240560117
Subject(s) - protein tyrosine phosphatase , tyrosine kinase , tyrosine , tyrosine phosphorylation , phosphorylation , mitogen activated protein kinase kinase , genistein , chemistry , receptor tyrosine kinase , platelet derived growth factor receptor , dephosphorylation , cyclin dependent kinase 9 , microbiology and biotechnology , biology , biochemistry , protein kinase a , signal transduction , phosphatase , endocrinology , growth factor , receptor
Modulation of protein Kinase F /GSK‐3α by tyrosine phosphorylation in A431 cells was investigated. Kinase F A /GSK‐3α was found to exist in a highly tyrosine‐phosphorylated/activated state in resting cells but could become tyrosine‐dephosphorylated and inactivated down to less than 30% of control values in concentration dependent manner by 50‐400 μM genistein( a Specific tyrosine kinase inhibitor), as demonstrated by metobolic 32 p‐labeling of the cells followed by immunoprecipitation and two‐dimensional phosphoamino acid analysis and byimmunodetection in an antikinase F A /GSK‐3α immunoprecipitate kinase assay. Taken together, the results provide evidence that Kinase F A /GSK‐3α may exist in a highly tyrosine‐phosphorylated/activated state in resting cells which can by tyrosine‐dephosphorylated and nactivated by extracellular stimulus and that tyrosine kinase(s) and /or tyrosine phosphatase(s) may play a role in the modulation of kinse F A /GSK‐3α activity in cells.