title: rab3 is a small GTP-binding protein exclusively localized to synaptic vesicles.
abstract: rab3, a low molecular weight GTP-binding protein, is primarily expressed in brain, where it is present in soluble and membrane-bound forms. Membrane-bound rab3 in brain is exclusively localized on synaptic vesicles, the secretory organelles of the synapse that store and release neurotransmitters. rab3 is also expressed in endocrine tissues such as the adrenal medulla, where it is found together with other synaptic vesicle proteins on microvesicles distinct from chromaffin granules. The tight binding of rab3 to membranes correlates with hydrophobic modifications that are different in the membrane-bound and soluble forms of rab3. The results demonstrate the exclusive targeting of a small GTP-binding protein to secretory vesicles of a subset of the regulated pathway of secretion.
authors.affiliation: Max-Planck-Institut für Psychiatrie, Planegg-Martinsried, Federal Republic of Germany.
authors.forename: G
authors.initials: G
authors.lastname: Fischer von Mollard
authors.forename: G A
authors.initials: GA
authors.lastname: Mignery
authors.forename: M
authors.initials: M
authors.lastname: Baumert
authors.forename: M S
authors.initials: MS
authors.lastname: Perin
authors.forename: T J
authors.initials: TJ
authors.lastname: Hanson
authors.forename: P M
authors.initials: PM
authors.lastname: Burger
authors.forename: R
authors.initials: R
authors.lastname: Jahn
authors.forename: T C
authors.initials: TC
authors.lastname: Südhof
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies; D002458:Cell Fractionation; D002540:Cerebral Cortex / Q000378:metabolism; D002837:Chromaffin Granules / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D019204:GTP-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009419:Nerve Tissue Proteins / Q000302:isolation & purification / Q000378:metabolism*; D011485:Protein Binding; D051381:Rats; D013572:Synaptic Vesicles / Q000378:metabolism*; D020692:rab3 GTP-Binding Proteins
chemical_list: D000906:Antibodies; D009419:Nerve Tissue Proteins; D019204:GTP-Binding Proteins; D020692:rab3 GTP-Binding Proteins