Physical and Functional Interaction of Rabphilin-3A with α-Actinin

Masaki Kato, Takuya Sasaki, Takeshi Ohya, Hiroyuki Nakanishi, Hideo Nishioka, Michihiro Imamura, Yoshimi Takai
1996 Journal of Biological Chemistry  
Rabphilin-3A is a downstream target molecule of Rab3A small GTP-binding protein and implicated in Ca 2؉dependent neurotransmitter release. Here we have isolated a rabphilin-3A-interacting molecule from a human brain cDNA library by the yeast two-hybrid method and identified it to be ␣-actinin, known to cross-link actin filaments into a bundle. ␣-Actinin interacts with the N-terminal region of rabphilin-3A, with which GTP- Rab3A interacts, and this interaction stimulates the activity of
more » ... to cross-link actin filaments into a bundle. The interaction of rabphilin-3A with ␣-actinin is inhibited by guanosine 5-(3-O-thio)triphosphate- Rab3A. These results suggest that the Rab3A-rabphilin-3A system regulates the ␣-actinin-regulated reorganization of actin filaments. It has been shown that reorganization of actin filaments is also involved in Ca 2؉dependent exocytosis. Therefore, rabphilin-3A may serve as a linker for Rab3A and cytoskeleton.
doi:10.1074/jbc.271.50.31775 pmid:8943213 fatcat:323qclsu35cx3bgt5ujlcgk75e