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Differential phosphorylation of SNAP‐25 in vivo by protein kinase C and protein kinase A
Author(s) -
Hepp Régine,
Cabaniols Jean-Pierre,
Roche Paul A
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)03629-3
Subject(s) - microbiology and biotechnology , phosphorylation , mitogen activated protein kinase kinase , protein phosphorylation , map2k7 , protein kinase a , exocytosis , chemistry , snap , biology , biochemistry , cyclin dependent kinase 2 , membrane , computer graphics (images) , computer science
SNAP‐25 is a key protein required for the fusion of synaptic vesicles with the plasma membrane during exocytosis. This study establishes that SNAP‐25 is differentially phosphorylated by protein kinase C and protein kinase A in neuroendocrine PC12 cells. Using phosphopeptide mapping and site‐directed mutagenesis we identified both Thr138 and Ser187 as the targets of SNAP‐25 phosphorylation by protein kinase C and Thr138 as the exclusive site of SNAP‐25 phosphorylation by protein kinase A in vivo. Finally, despite published data to the contrary, we demonstrate that stimulation of regulated exocytosis under physiological conditions is independent of a measurable increase in SNAP‐25 phosphorylation in PC12 cells.