Phosphorylation of Rabphilin-3A by Calmodulin-Dependent Protein Kinase II

• Published in: Biochemical and biophysical research communications Vol. 205; no. 3; pp. 1776 - 1784
• Main Authors: Kato, M., Sasaki, T., Imazumi, K., Takahashi, K., Araki, K., Shirataki, H., Matsuura, Y., Ishida, A., Fujisawa, H., Takai, Y.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 30.12.1994
• Subjects: Adaptor Proteins, Signal Transducing; Amino Acid Sequence; Animals; Binding Sites - genetics; Brain - enzymology; Calcium-Calmodulin-Dependent Protein Kinase Type 2; Calcium-Calmodulin-Dependent Protein Kinases - metabolism; Cell-Free System; Cloning, Molecular; GTP-Binding Proteins - genetics; GTP-Binding Proteins - metabolism; In Vitro Techniques; Molecular Sequence Data; Nerve Tissue Proteins - genetics; Nerve Tissue Proteins - metabolism; Neurotransmitter Agents - metabolism; Phosphorylation; rab GTP-Binding Proteins; Rabphilin-3A; Rats; Recombinant Proteins - genetics; Recombinant Proteins - metabolism; Spodoptera; Vesicular Transport Proteins
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1006/bbrc.1994.2875

Rabphilin-3A is a putative target protein for Rab3A small GTP-binding protein which is implicated in neurotransmitter release. We have examined here whether Rabphilin-3A is phosphorylated by calmodulin-dependent protein kinase II (CaMKII). Recombinant Rabphilin-3A was phosphorylated by CaMKII purified from rat brain. Two moles of phosphate were maximally incorporated into one mole of Rabphilin-3A. The phosphorylation sites were Ser 34, Thr 205, Thr 209, and Thr 537. These results suggest that the CaMKII-catalyzed phosphorylation of Rabphilin-3A may modulate neurotransmitter release.