Abstract
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 32p‐labeling of the cells followed by immunoprecipitation and two‐dimensional phosphoamino acid analysis and byimmunodetection in an antikinase FA/GSK‐3α immunoprecipitate kinase assay. Taken together, the results provide evidence that Kinase FA/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 FA/GSK‐3α activity in cells.
Original language | English |
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Pages (from-to) | 131-141 |
Number of pages | 11 |
Journal | Journal of Cellular Biochemistry |
Volume | 56 |
Issue number | 1 |
DOIs | |
State | Published - 09 1994 |
Keywords
- A431 cells
- genistein
- inactivation
- kinase FQGSK‐3α
- tyrosine dephosphorlation