... experiments. Here, we extended our in vivo analysis on the production of regulatory Arf-GDP and observed that ArfGAP2 and ArfGAP3 do not play a role in GBF1 recruitment. We confirm that Arf-GDP localization is critical, as a TGN-localized Arf-GDP mutant protein fails to promote GBF1 recruitment. We also...

...Chia-Jung Yu; Fang-Jen S. Lee ABSTRACT ADP-ribosylation factors (Arfs) and ADP-ribosylation factor-like proteins (Arls) are highly conserved small GTPases that function as main regulators of vesicular trafficking and cytoskeletal reorganization. Arl1, the first identified member of the large Arl...

...Jia-Wei Hsu; Zzu-Jung Chen; Ya-Wen Liu; Fang-Jen S. Lee ABSTRACT Small GTPase ADP-ribosylation factors (ARFs) are key regulators of membrane trafficking and their activities are determined by guanine-nucleotide-binding status. In Saccharomyces cerevisiae , Arl1p, an ARF-like protein, is responsible...

...Douglas Quilty; Fraser Gray; Nathan Summerfeldt; Dan Cassel; Paul Melançon ABSTRACT ADP-ribosylation factors (Arfs) play central roles in the regulation of vesicular trafficking through the Golgi. Arfs are activated at the Golgi membrane by guanine-nucleotide-exchange factors (GEFs...

... compartments is a fundamental cellular activity. In Saccharomyces cerevisiae , disruption of the ADP-ribosylation factor 1 ( ARF1 ) gene yields larger and fewer Golgi cisternae by partially depleting the Arf GTPase. We observed a similar phenotype with a thermosensitive mutation in Nmt1, which myristoylates...

... clear that autophagy intersects with multiple steps of the endocytic and exocytic pathways, sharing many molecular players. A number of Rab and Arf GTPases that are involved in the regulation of the secretory and the endocytic membrane trafficking pathways, have been shown to play key roles in autophagy...

...Seung Ja Oh; Lorraine C. Santy Summary Recycling of internalized integrins is a crucial step in adhesion remodeling and cell movement. Recently, we determined that the ADP-ribosylation factor–guanine nucleotide exchange factors (ARF-GEFs) cytohesin 2/ARNO and cytohesin 3/GRP1 have opposing effects...

..., suggesting that Garz cycles in a GEF-activity-dependent manner between cytoplasmic and Golgi-membrane-localized pools. The related human ARF-GEF protein GBF1 can substitute for garz function in Drosophila tracheal cells, indicating that the relevant functions of these proteins are conserved. We show...

...Yu-Chun Lin; Tsai-Chen Chiang; Yu-Tsan Liu; Yueh-Tso Tsai; Li-Ting Jang; Fang-Jen S. Lee ADP-ribosylation factor-like protein 4A (ARL4A) is a developmentally regulated member of the ARF/ARL GTPase family. The primary structure of ARL4A is very similar to that of other ARF/ARL molecules, but its...

...-ribosylation factors (Arfs) are ~20 kDa GTP-binding proteins that are required for protein traffic at the level of the Golgi complex and early endosomes. In this study, we expressed mutants and protein fragments that bind to Arf-GTP to show that Arf1, but not Arf6 is required for transport of Shiga toxin from...

...-ribosylation factor (ARF) or the ARF-activating guanine nucleotide exchange factor GBF1, or by treating cells with brefeldin A (BFA), causes the collapse of the Golgi into the endoplasmic reticulum (ER) and arrests trafficking of soluble and transmembrane proteins at the ER. Here, we assess COPI function...

...Carlene D. Moore; Erin E. Thacker; Jennifer Larimore; David Gaston; Alison Underwood; Brian Kearns; Sean I. Patterson; Trevor Jackson; Chris Chapleau; Lucas Pozzo-Miller; Anne Theibert Centaurin α1 is an Arf GTPase-activating protein (GAP) that is highly expressed in the nervous system...

... RhoA-GTP binding and ArfGAP activity. ‡ Author for correspondence (e-mail: randazzo@helix.nih.gov ) * Present address: Osaka Bioscience Institute, 6-2-4 Furuedai, Suita,Osaka 565-0874, Japan 31 8 2006 © The Company of Biologists Limited 2006 2006 Actin Rho Arf...

...Ya-Wen Liu; Szu-Wei Lee; Fang-Jen S. Lee The molecular mechanisms involved in the transport of GPI-anchored proteins from the trans-Golgi network (TGN) to the cell periphery have not been established. Arl1p is a member of the Arf-like protein (Arl) subfamily of small GTPases and is localized...

...S.-H. Kim; J. Rowe; H. Fujii; R. Jones; B. Schmierer; B.-W. Kong; K. Kuchler; D. Foster; D. Ish-Horowicz; G. Peters In mammalian cells, products of the INK4a-ARF locus play major roles in senescence and tumour suppression in different contexts, whereas the adjacent INK4b gene is more generally...

...Sonja Krugmann; Simon Andrews; Len Stephens; Phillip T. Hawkins Rho and Arf family small GTPases control dynamic actin rearrangements and vesicular trafficking events. ARAP3 is a dual GAP for RhoA and Arf6 that is regulated by phosphatidylinositol (3,4,5)-trisphosphate [PtdIns(3,4,5) P 3...

... and ultrastructural analyses. A statistical analysis established a product precursor relationship demonstrating that the coated vesicles are indeed generated from large donor liposomes( Bremser et al., 1999 ). ARF-dependent GTP hydrolysis has been demonstrated to initiate COPI vesicle uncoating ( Tanigawa et al...

... protein domains are present in all GGA proteins, as defined by sequence homology and function. These different domains interact directly with ARF proteins, cargo and clathrin. Alteration of the levels of GGA proteins by gene knockout or overexpression affects specific trafficking events between the trans...