title: rab15, a novel low molecular weight GTP-binding protein specifically expressed in rat brain.
abstract: rab3A is a low molecular weight (LMW) GTP-binding protein specifically expressed in brain and localized to synaptic vesicles. rab3A has been proposed to play a role in neurotransmitter release by regulating membrane flow in the nerve terminal. In an attempt to define other LMW GTP-binding proteins that may regulate neurotransmitter release, seven cDNA clones encoding new members of the rab family of LMW GTP-binding proteins were isolated from a rat brain cDNA library. The rab proteins contain the four conserved structural domains essential for GTP binding in addition to domains required for membrane localization and effector protein interactions. One protein, rab16, is closely related to members of the rab3 subfamily, whereas two others are assigned as the rat homologs of canine rab8 and rab10. Four additional clones, rab12, rab13, rab14, and rab15, revealed unique sequences and are new members of the rab family of LMW GTP-binding proteins. The patterns of expression of rab15 and rab3A closely overlap but differ from that observed for all other known LMW GTP-binding proteins. This data suggests that rab15 may act in concert with rab3A in regulating aspects of synaptic vesicle membrane flow within the nerve terminal.
authors.affiliation: Howard Hughes Medical Institute, Department of Molecular and Cellular Physiology, Beckman Center, Stanford University, California 94305.
authors.forename: L A
authors.initials: LA
authors.lastname: Elferink
authors.forename: K
authors.initials: K
authors.lastname: Anzai
authors.forename: R H
authors.initials: RH
authors.lastname: Scheller
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D001921:Brain / Q000378:metabolism*; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D019204:GTP-Binding Proteins / Q000235:genetics*; D015723:Gene Library; D006801:Humans; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D015345:Oligonucleotide Probes; D009928:Organ Specificity; D051381:Rats; D012689:Sequence Homology, Nucleic Acid; D013116:Spinal Cord / Q000378:metabolism; D020692:rab3 GTP-Binding Proteins
chemical_list: D009419:Nerve Tissue Proteins; D015345:Oligonucleotide Probes; D004247:DNA; D019204:GTP-Binding Proteins; D020692:rab3 GTP-Binding Proteins