title: Heterotetramer formation of prenylated Rab3A with two Rabphilin-3A molecules.
abstract: Rab3A small GTP-binding protein and its putative target protein, named Rabphilin-3A, are implicated in neurotransmitter release. We have investigated here the function of the lipid modifications of Rab3A (Mr approximately 25,000) in its interaction with Rabphilin-3A (Mr approximately 80,000). Lipid-modified GTP-Rab3A dimerized and lipid-unmodified one monomerized. Lipid-modified GTP-Rab3A (Mr approximately 50,000) formed a heterotetramer (Mr approximately 210,000) with two Rabphilin-3A molecules, whereas lipid-unmodified GTP-Rab3A formed a heterodimer (Mr approximately 105,000) with one Rabphilin-3A molecule. These results indicate that two lipid-modified GTP-Rab3A molecules form a heterotetramer with two Rabphilin-3A molecules.
authors.affiliation: Department of Molecular Biology and Biochemistry, Osaka University Medical School, Suita, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Takahashi
authors.forename: T
authors.initials: T
authors.lastname: Sasaki
authors.forename: Y
authors.initials: Y
authors.lastname: Takai
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D002417:Cattle; D019204:GTP-Binding Proteins / Q000737:chemistry*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000737:chemistry; D008055:Lipids / Q000737:chemistry; D046911:Macromolecular Substances; D008970:Molecular Weight; D009419:Nerve Tissue Proteins / Q000737:chemistry*; D011485:Protein Binding; D014461:Ultracentrifugation; D033921:Vesicular Transport Proteins; D020691:rab GTP-Binding Proteins; D020692:rab3 GTP-Binding Proteins; D000097624:Rabphilin-3A
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D019204:GTP-Binding Proteins; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D008055:Lipids; D046911:Macromolecular Substances; D009419:Nerve Tissue Proteins; D033921:Vesicular Transport Proteins; D020691:rab GTP-Binding Proteins; D020692:rab3 GTP-Binding Proteins; D000097624:Rabphilin-3A