Phosphorylation of Rabphilin-3A, a putative target protein for Rab3A, by cyclic AMP-dependent protein kinase.
Rab3A small GTP-binding protein and its associated proteins, such as Rabphilin-3A, a putative target protein for Rab3A, MSS4, a stimulatory GDP/GTP exchange protein for Rab3A, and Rab GDI, a translocator for the Rab family members including Rab3A, are implicated in neurotransmitter release. We have investigated here the phosphorylation of these proteins by cyclic AMP-dependent protein kinase (protein kinase A). Neither Rab3A, MSS4, nor Rab GDI was phosphorylated, but Rabphilin-3A was phosphorylated Rab GDI was phosphorylated, but Rabphilin-3A was phosphorylated at its N-terminal region. About 0.8 mol of phosphate was maximally incorporated into one mol of Rabphilin-3A. These results suggest that Rabphilin-3A is one of the targets for protein kinase A which modulates neurotransmitter release.
Numata
S
S
Department of Cell Physiology, National Institute for Physiological Sciences, Okazaki, Japan.
Shirataki
H
H
Hagi
S
S
Yamamoto
T
T
Takai
Y
Y
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D009419:Nerve Tissue Proteins / Q000302:isolation & purification / Q000378:metabolism*; D009842:Oligopeptides / Q000378:metabolism; D010766:Phosphorylation; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D018411:Spodoptera; D013379:Substrate Specificity; D014162:Transfection; D033921:Vesicular Transport Proteins; D020691:rab GTP-Binding Proteins; D020692:rab3 GTP-Binding Proteins; D000097624:Rabphilin-3A
D048868:Adaptor Proteins, Signal Transducing; D017868:Cyclic AMP-Dependent Protein Kinases; D019204:GTP-Binding Proteins; D009419:Nerve Tissue Proteins; D009842:Oligopeptides; D011994:Recombinant Proteins; D033921:Vesicular Transport Proteins; D020691:rab GTP-Binding Proteins; D020692:rab3 GTP-Binding Proteins; D000097624:Rabphilin-3A; C037642:kemptide