Arf1-GTP-induced Tubule Formation Suggests a Function of Arf Family Proteins in Curvature Acquisition at Sites of Vesicle Budding

• Published in: The Journal of biological chemistry Vol. 283; no. 41; pp. 27717 - 27723
• Main Authors: Krauss, Michael, Jia, Jun-Yong, Roux, Aurélien, Beck, Rainer, Wieland, Felix T., De Camilli, Pietro, Haucke, Volker
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 10-10-2008; American Society for Biochemistry and Molecular Biology
• Subjects: ADP-Ribosylation Factor 1 - chemistry; ADP-Ribosylation Factor 1 - genetics; ADP-Ribosylation Factor 1 - metabolism; Animals; Chlorocebus aethiops; Coat Protein Complex I - chemistry; Coat Protein Complex I - genetics; Coat Protein Complex I - metabolism; COP-Coated Vesicles - chemistry; COP-Coated Vesicles - genetics; COP-Coated Vesicles - metabolism; COS Cells; Endocytosis - physiology; Enzyme Catalysis and Regulation; Exocytosis - physiology; Golgi Apparatus - chemistry; Golgi Apparatus - genetics; Golgi Apparatus - metabolism; Guanosine Triphosphate - chemistry; Guanosine Triphosphate - metabolism; HeLa Cells; Humans; Liposomes - chemistry; Microtubules - genetics; Microtubules - metabolism; Rats
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M804528200

ADP-ribosylation factor (Arf) and related small GTPases play crucial roles in membrane traffic within the exo- and endocytic pathways. Arf proteins in their GTP-bound state are associated with curved membrane buds and tubules, frequently together with effector coat proteins to which they bind. Here we report that Arf1 is found on membrane tubules originating from the Golgi complex where it colocalizes with COPI and GGA1 vesicle coat proteins. Arf1 also induces tubulation of liposomes in vitro. Mutations within the amino-terminal amphipathic helix (NTH) of Arf1 affect the number of Arf1-positive tubules in vivo and its property to tubulate liposomes. Moreover, hydrophilic substitutions within the hydrophobic part of its NTH impair Arf1-catalyzed budding of COPI vesicles in vitro. Our data indicate that GTP-controlled local induction of high curvature membranes is an important property of Arf1 that might be shared by a subgroup of Arf/Arl family GTPases.