title: Knockout of Arfrp1 leads to disruption of ARF-like1 (ARL1) targeting to the trans-Golgi in mouse embryos and HeLa cells.
abstract: ADP-ribosylation factor related protein 1 (ARFRP1) is a member of the ARF-family of GTPases which operate as molecular switches in the regulation of intracellular protein traffic. Deletion of the mouse Arfrp1 gene leads to embryonic lethality during early gastrulation, suggesting that ARFRP1 is required for cell adhesion-related processes. Here we show that ARFRP1 specifically controls targeting of ARL1 and its effector Golgin-245 to the trans-Golgi. GTP-bound ARFRP1 (ARFRP1-Q79L mutant) is associated with Golgi membranes and co-localized with the GTPase ARL1. In contrast, the guanine nucleotide exchange defective ARFRP1 mutant (ARFRP1-T31N) clusters within the cytosol. ARFRP1-T31N or depletion of endogenous ARFRP1 by RNA interference disrupts the Golgi association of ARL1 and of the GRIP-domain protein Golgin-245 and alters the distribution of a trans-Golgi network marker, syntaxin 6. In contrast, the targeting of two other Golgi-associated proteins, GM130 and giantin, was unaffected. Furthermore, in Arfrp1-/ - embryos ARL1 dislocated from Golgi membranes whereas it was associated with intracellular membranes in wild-type embryos. These data suggest that lethality of Arfrp1 knockout embryos is due to a specific disruption of protein targeting, e.g., of ARL1 and Golgin-245, to the Golgi.
authors.affiliation: Department of Pharmacology, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Zahn
authors.forename: Angela
authors.initials: A
authors.lastname: Hommel
authors.forename: Lei
authors.initials: L
authors.lastname: Lu
authors.forename: Wanjin
authors.initials: W
authors.lastname: Hong
authors.forename: Diego J
authors.initials: DJ
authors.lastname: Walther
authors.forename: Simone
authors.initials: S
authors.lastname: Florian
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Joost
authors.forename: Annette
authors.initials: A
authors.lastname: Schürmann
mesh_terms: D020823:ADP-Ribosylation Factor 1 / Q000235:genetics* / Q000378:metabolism; D020727:ADP-Ribosylation Factors / Q000378:metabolism*; D000818:Animals; D001324:Autoantigens / Q000378:metabolism; D004622:Embryo, Mammalian / Q000378:metabolism; D020558:GTP Phosphohydrolases / Q000235:genetics; D020868:Gene Silencing; D006056:Golgi Apparatus / Q000378:metabolism*; D006153:Guanosine Diphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D021381:Protein Transport; D014162:Transfection; D021601:trans-Golgi Network / Q000378:metabolism*
chemical_list: D001324:Autoantigens; C098772:GOLGA4 protein, human; D008565:Membrane Proteins; D006153:Guanosine Diphosphate; D006160:Guanosine Triphosphate; C097313:ADP-ribosylation factor related proteins; D020558:GTP Phosphohydrolases; D020823:ADP-Ribosylation Factor 1; D020727:ADP-Ribosylation Factors