© 2004 The Japanese Biochemical Society
JB MINIREVIEWS |
COPII Coat Assembly and Selective Export from the Endoplasmic Reticulum
Molecular Membrane Biology Laboratory, RIKEN Discovery Research Institute, and PRESTO, Japan Science and Technology Agency, Hirosawa, Wako, Saitama 351-0198
The coat protein complex II (COPII) generates transport vesicles that mediate protein transport from the endoplasmic reticulum (ER). Recent structural and biochemical studies have suggested that the COPII coat is responsible for direct capture of membrane cargo proteins and for the physical deformation of the ER membrane that drives the transport vesicle formation. The COPII-coated vesicle formation at the ER membrane is triggered by the activation of the Ras-like small GTPase Sar1 by GDP/GTP exchange, and activated Sar1 in turn promotes COPII coat assembly. Subsequent GTP hydrolysis by Sar1 leads to disassembly of the coat proteins, which are then recycled for additional rounds of vesicle formation. Thus, the Sar1 GTPase cycle is thought to regulate COPII coat assembly and disassembly. Emerging evidence suggests that the cargo proteins modulate the Sar1 GTP hydrolysis to coordinate coat assembly with cargo selection. Here, I discuss the possible roles of the GTP hydrolysis by Sar1 in COPII coat assembly and selective uptake of cargo proteins into transport vesicles.
* For correspondence: Phone: +81-48-467-9549, Fax: +81-48-462-4679, E-mail: kensato{at}riken.jp
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  K. Hatsuzawa, T. Tamura, H. Hashimoto, H. Hashimoto, S. Yokoya, M. Miura, H. Nagaya, and I. Wada Involvement of Syntaxin 18, an Endoplasmic Reticulum (ER)-localized SNARE Protein, in ER-mediated Phagocytosis Mol. Biol. Cell, September 1, 2006; 17(9): 3964 - 3977. [Abstract] [Full Text] [PDF]
|
|