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p38 mitogen‐activated protein kinase dephosphorylation is regulated by protein phosphatase 2A in human platelets activated by collagen
Author(s) -
Sundaresan Pavithra,
Farndale Richard W
Publication year - 2002
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(02)03277-5
Subject(s) - dephosphorylation , protein phosphatase 2 , phosphatase , phosphorylation , chemistry , p38 mitogen activated protein kinases , phenylarsine oxide , protein kinase a , mitogen activated protein kinase , okadaic acid , microbiology and biotechnology , platelet , biochemistry , biology , immunology , enzyme
Collagen and the cross‐linked collagen‐related peptide (CRP‐XL) each induced platelet p38 mitogen‐activated protein kinase (p38) phosphorylation after 2 min. Subsequent dephosphorylation occurred in platelets activated with collagen, but not with CRP‐XL, demonstrating glycoprotein VI‐independent regulation of p38. Okadaic acid and fostriecin, inhibitors specific for protein phosphatase 2A (PP2A), blocked p38 dephosphorylation, and PP2A co‐immunoprecipitated with phospho‐p38. In addition, use of phenylarsine oxide suggested that tyrosine phosphatases and PP2A may act in concert to dephosphorylate p38. Finally, regulation of p38 in collagen‐stimulated Glanzmann's platelets was indistinguishable from that in normal platelets, showing that p38 regulation is independent of integrin αIIbβ3.