The Arf-like GTPase Arl1 and its role in membrane traffic.
Small GTP-binding proteins of the Rab and Arf (ADP-ribosylation factor) families play a central role in the membrane trafficking pathways of eukaryotic cells. The prototypical members of the Arf family are Arf1-Arf6 and Sar1, which have well-characterized roles in membrane traffic or cytoskeletal reorganization. However, eukaryotic genomes encode additional proteins, which share the characteristic structural features of the Arf family, but the role of these 'Arf-like' (Arl) proteins is less well understood. This review discusses Arl1, a GTPase that is widely conserved in evolution, and which is localized to the Golgi in all species so far examined. The best-characterized effectors of Arl1 are coiled-coil proteins which share a C-terminal GRIP domain, but other apparent effectors include the GARP (Golgi-associated retrograde protein)/VFT (Vps fifty-three) vesicle-tethering complex and Arfaptin 2. As least some of these proteins are believed to have a role in membrane traffic. Genetic analysis in a number of species has shown that Arl1 is not essential for exocytosis, but rather suggest that it is required for traffic from endosomes to the Golgi.
Munro
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MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK. sean@mrc-lmb.cam.ac.uk
D020727:ADP-Ribosylation Factors / Q000737:chemistry / Q000502:physiology*; D000818:Animals; D002462:Cell Membrane / Q000502:physiology*; D020690:GTPase-Activating Proteins / Q000378:metabolism*; D006056:Golgi Apparatus / Q000502:physiology; D006160:Guanosine Triphosphate / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000502:physiology*; D008958:Models, Molecular; D011487:Protein Conformation
D020690:GTPase-Activating Proteins; D008565:Membrane Proteins; D006160:Guanosine Triphosphate; C097313:ADP-ribosylation factor related proteins; D020727:ADP-Ribosylation Factors