GBF1 Guanine-nucleotide exchange factor (GEF) for members of the Arf family of small GTPases involved in trafficking in the early secretory pathway; its GEF activity initiates the coating of nascent vesicles via the localized generation of activated ARFs through replacement of GDP with GTP. Recruitment to cis-Golgi membranes requires membrane association of Arf-GDP and can be regulated by ARF1, ARF3, ARF4 and ARF5. Involved in the recruitment of the COPI coat complex to the endoplasmic reticulum exit sites (ERES), and the endoplasmic reticulum-Golgi intermediate (ERGIC) and cis-Golgi compartments which implicates ARF1 activation. Involved in COPI vesicle-dependent retrograde transport from the ERGIC and cis-Golgi compartments to the endoplasmic reticulum (ER). Involved in the trans-Golgi network recruitment of GGA1, GGA2, GGA3, BIG1, BIG2, and the AP-1 adaptor protein complex related to chlathrin-dependent transport; the function requires its GEF activity (probably at least in part on ARF4 and ARF5). Has GEF activity towards ARF1. Has in vitro GEF activity towards ARF5. Involved in the processing of PSAP. Required for the assembly of the Golgi apparatus. The AMPK-phosphorylated form is involved in Golgi disassembly during mitotis and under stress conditions. May be involved in the COPI vesicle-dependent recruitment of PNPLA2 to lipid droplets; however, this function is under debate. In neutrophils, involved in G protein-coupled receptor (GPCR)-mediated chemotaxis und superoxide production. Proposed to be recruited by phosphatidylinositol-phosphates generated upon GPCR stimulation to the leading edge where it recruits and activates ARF1, and is involved in recruitment of GIT2 and the NADPH oxidase complex. Ubiquitous. 3 alternatively spliced human isoforms have been reported. Note: This description may include information from UniProtKB.
Protein type: GEF; GEF, ARF
Chromosomal Location of human Ortholog: 10q24.32
Cellular Component:  cell leading edge; cis-Golgi network; cytosol; endoplasmic reticulum lumen; endoplasmic reticulum-Golgi intermediate compartment; Golgi apparatus; Golgi membrane; Golgi stack; lipid droplet; mitochondrion; peroxisome; trans-Golgi network
Molecular Function:  ARF guanyl-nucleotide exchange factor activity; guanyl-nucleotide exchange factor activity; phosphatidylinositol-3,4,5-trisphosphate binding; phosphatidylinositol-3,5-bisphosphate binding; protein binding
Biological Process:  cell activation involved in immune response; cellular response to virus; COPI coating of Golgi vesicle; endoplasmic reticulum-Golgi intermediate compartment organization; ER to Golgi vesicle-mediated transport; establishment of monopolar cell polarity; Golgi disassembly; Golgi organization; Golgi to endosome transport; neutrophil chemotaxis; post-Golgi vesicle-mediated transport; protein localization to endoplasmic reticulum exit site; protein localization to endoplasmic reticulum tubular network; protein localization to Golgi apparatus; protein transport; reactive oxygen species biosynthetic process; regulation of ARF protein signal transduction; regulation of mitotic cell cycle; regulation of protein localization to cell surface; retrograde transport, endosome to Golgi; retrograde vesicle-mediated transport, Golgi to ER; viral process
Disease: Charcot-marie-tooth Disease, Axonal, Type 2gg
Reference #:  Q92538 (UniProtKB)
Alt. Names/Synonyms: ARF1GEF; BFA-resistant GEF 1; FLJ21263; FLJ21500; GBF1; golgi brefeldin A resistant guanine nucleotide exchange factor 1; golgi-specific brefeldin A resistance factor 1; golgi-specific brefeldin A resistant guanine nucleotide exchange factor 1; golgi-specific brefeldin A-resistance factor 1; Golgi-specific brefeldin A-resistance guanine nucleotide exchange factor 1; KIAA0248; MGC134877; MGC134878
Gene Symbols: GBF1
Molecular weight: 206,446 Da
Basal Isoelectric point: 5.48  Predict pI for various phosphorylation states
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Protein Structure Not Found.

Cross-references to other databases:  AlphaFold  |  STRING  |  cBioPortal  |  Wikipedia  |  Reactome  |  neXtProt  |  Protein Atlas  |  BioGPS  |  Pfam  |  Phospho.ELM  |  NetworKIN  |  GeneCards  |  UniProtKB  |  Entrez-Gene  |  GenPept  |  Ensembl Gene  |  Ensembl Protein