ADP-Ribosylation factor 1 (ARF 1) from MyBioSource.com

Ras superfamily of small GTPases regulates a wide variety of cellular processes including intracellular trafficking of proteins. The Ras proteins acts as molecular switches by cycling between inactive GDP-bound and active GTP-bound state. Guanine exchange factors (GEFs) Among the various Ras proteins, the ADPribosylation factor proteins (ARFs) are well characterized regulators of vesicle formation in intracellular membrane traffic while Rho proteins regulate the actin cytoskeleton (1). The Arf family members have unique structural device, called the 'interswitch toggle', that implements communication between the nucleotidebinding site and a unique N-terminal amphipathic helix that mediates the interaction of Arf proteins with membranes, these structural motifs distinguish them from other small GTPases (2). When GDP is bound to ARF proteins the amphipathic helix is positioned in a hydrophobic pocket, whereas in the GTP-bound forms it is displaced by the interswitch toggle and stabilizes interaction of the protein with membrane lipid bilayer. Thus, the GTP-GDP cycle is coupled to membrane-cytosol cycle and thereby ARF proteins are able to regulate vesicular traffic and organelle structure formation (2). The mammalian ARF family comprise of 5 members (ARF1-6), there is no ARF2. ARF1 and ARF6 are most abundantly expressed and located in distinct cellular locations at Golgi complex and early-endosome-plasma membrane interface and are most distantly related with only 67% sequence identity. ARF1 is mostly known for its role in vesicle budding and Golgi regulation through the recruitment of coat proteins and in the regulation of lipid-modifying enzymes and actin organizing components (3). The crystal structure of ARF-BD (ARF binding domain) comprise of a PH domain adjacent to a C-terminal helix and ARF interacts with these two regions via its "interswitch toggle" (4). ARF1 protein has 188 amino acids and is expressed in at least 3 variant forms, ARF1 antibodies will label all variants equally. The deactivation of ARF1 induces redistribution of entire Golgi complex to ER, the GTP bound form triggers the association with coat protein with the Golgi membranes. Purified ARF proteins do not have GTPase activity suggesting that GTP hydrolysis is dependent on GTPase activating protein (GAP) a 49kDa protein (4). The GTP bound ARF1 and 3 proteins also interact with several interacting protein (ARFGAPs) including protein interacting with C kinase 1 (PICK1) to mediate their cellular processes. ARF1-selective antibodies were generated against unique antigenic peptide sequences form ARF1 protein, this peptide sequence was not found in any other protein listed in the gene bank. The ARF1 antibodies were affinity purified over immobilized antigen based chromatography, and the purified immunoglobulins are stabilized in antibody stabilization buffer. MyBioSource will also provide limited quantities of antigenic blocking peptide for ARF1. Antibodies to several other Ras targets are available from MyBioSource. For a complete list of antibodies please visit http://www.mybiosource.com. MyBioSource will conjugate antibodies with secondary enzymes (alk-Pase or HRP) or fluorescent probes upon request at a nominal cost