Arf1-GTP-induced tubule formation suggests a function of Arf family proteins in curvature acquisition at sites of vesicle budding.
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.
Krauss
Michael
M
Institute of Chemistry and Biochemistry, Department of Membrane Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany.
Jia
Jun-Yong
JY
Institute of Chemistry and Biochemistry, Department of Membrane Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany.
Roux
Aurélien
A
Department of Cell Biology and Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut 06510.
Beck
Rainer
R
Biochemie-Zentrum (BZH), University of Heidelberg, 69120 Heidelberg, Germany.
Wieland
Felix T
FT
Biochemie-Zentrum (BZH), University of Heidelberg, 69120 Heidelberg, Germany.
De Camilli
Pietro
P
Department of Cell Biology and Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut 06510.
Haucke
Volker
V
Institute of Chemistry and Biochemistry, Department of Membrane Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany. Electronic address: v.haucke@biochemie.fu-berlin.de.
D020823:ADP-Ribosylation Factor 1 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D022181:COP-Coated Vesicles / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019556:COS Cells; D002522:Chlorocebus aethiops; D020755:Coat Protein Complex I / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004705:Endocytosis / Q000502:physiology*; D005089:Exocytosis / Q000502:physiology*; D006056:Golgi Apparatus / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000737:chemistry / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008081:Liposomes / Q000737:chemistry; D008870:Microtubules / Q000235:genetics / Q000378:metabolism*; D051381:Rats
D020755:Coat Protein Complex I; D008081:Liposomes; D006160:Guanosine Triphosphate; D020823:ADP-Ribosylation Factor 1