A tyrosine-based motif localizes a Drosophila vesicular transporter to synaptic vesicles in vivo.
Vesicular neurotransmitter transporters must localize to synaptic vesicles (SVs) to allow regulated neurotransmitter release at the synapse. However, the signals required to localize vesicular proteins to SVs in vivo remain unclear. To address this question we have tested the effects of mutating proposed trafficking domains in Drosophila orthologs of the vesicular monoamine and glutamate transporters, DVMAT-A and DVGLUT. We show that a tyrosine-based motif (YXXY) is important both for DVMAT-A internalization from the cell surface in vitro, and localization to SVs in vivo. In contrast, DVGLUT deletion mutants that lack a putative C-terminal trafficking domain show more modest defects in both internalization in vitro and trafficking to SVs in vivo. Our data show for the first time that mutation of a specific trafficking motif can disrupt localization to SVs in vivo and suggest possible differences in the sorting of VMATs versus VGLUTs to SVs at the synapse.
Grygoruk
Anna
A
Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, Hatos Center for Neuropharmacology, David Geffen School of Medicine, UCLA, Los Angeles, California 90095-1761, USA.
Fei
Hao
H
Daniels
Richard W
RW
Miller
Bradley R
BR
Diantonio
Aaron
A
Krantz
David E
DE
D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D004705:Endocytosis / Q000502:physiology; D006801:Humans; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D016415:Sequence Alignment; D009435:Synaptic Transmission / Q000502:physiology; D013572:Synaptic Vesicles / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism*; D050496:Vesicular Glutamate Transport Proteins / Q000235:genetics / Q000378:metabolism*; D050493:Vesicular Monoamine Transport Proteins / Q000235:genetics / Q000378:metabolism*
D029721:Drosophila Proteins; D050496:Vesicular Glutamate Transport Proteins; D050493:Vesicular Monoamine Transport Proteins; D014443:Tyrosine