title: ZnT-3, a putative transporter of zinc into synaptic vesicles.
abstract: The murine ZnT3 gene was cloned by virtue of its homology to the ZnT2 gene, which encodes a membrane protein that facilitates sequestration of zinc in endosomal vesicles. ZnT-3 protein is predicted to have six transmembrane domains and shares 52% amino acid identity with ZnT-2, with the homology extending throughout the two sequences. Human ZnT-3 cDNAs were also cloned; the amino acid sequence is 86% identical to murine ZnT-3. The mouse ZnT3 gene has 8 exons and maps to chromosome 5. Northern blot and reverse transcriptase-PCR analyses demonstrate that murine ZnT-3 expression is restricted to the brain and testis. In situ hybridization reveals that within the brain, ZnT-3 mRNA is most abundant in the hippocampus and cerebral cortex. Antibodies raised against the C-terminal tail of mouse ZnT-3 react with the projections from these neurons and produce a pattern similar to that obtained with Timm's reaction, which reveals histochemically reactive zinc within synaptic vesicles. We propose that ZnT-3 facilitates the accumulation of zinc in synaptic vesicles.
authors.affiliation: Howard Hughes Medical Institute, University of Washington, Seattle 98195, USA. palmiter@u.washington.edu
authors.forename: R D
authors.initials: RD
authors.lastname: Palmiter
authors.forename: T B
authors.initials: TB
authors.lastname: Cole
authors.forename: C J
authors.initials: CJ
authors.lastname: Quaife
authors.forename: S D
authors.initials: SD
authors.lastname: Findley
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D027682:Cation Transport Proteins; D003001:Cloning, Molecular; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D026901:Membrane Transport Proteins; D051379:Mice; D008969:Molecular Sequence Data; D017421:Sequence Analysis; D013572:Synaptic Vesicles / Q000378:metabolism*; D015032:Zinc / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D027682:Cation Transport Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; C102806:SLC30A3 protein, human; C491177:Slc30a3 protein, mouse; D015032:Zinc