A conserved mechanism of synaptogyrin localization.
We have studied the localization of synaptogyrin family members in vivo. Both native and green fluorescent protein (GFP)-tagged Caenorhabditis elegans synaptogyrin (SNG-1) are expressed in neurons and synaptically localized. Deletion and mutational analysis with the use of GFP-tagged SNG-1 has defined a 38 amino acid sequence within the C terminus of SNG-1 and a single arginine in the cytoplasmic loop between transmembrane domain 2 and 3 that are required for SNG-1 localization. These domains may represent components of signals that target synaptogyrin for endocytosis from the plasma membrane and direct synaptogyrin to synaptic vesicles, respectively. In chimeric studies, these regions were sufficient to relocalize cellugyrin, a nonneuronal form of synaptogyrin, from nonsynaptic regions such as the sensory dendrites and the cell body to synaptic vesicles. Furthermore, GFP-tagged rat synaptogyrin is synaptically localized in neurons of C. elegans and in cultured hippocampal neurons. Similarly, the C-terminal domain of rat synaptogyrin is necessary for localization in hippocampal neurons. Our study suggests that the mechanisms for synaptogyrin localization are likely to be conserved from C. elegans to vertebrates.
Zhao
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Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
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D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D005075:Biological Evolution; D017173:Caenorhabditis elegans / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins; D002478:Cells, Cultured; D017930:Genes, Reporter; D006624:Hippocampus / Q000166:cytology; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D021382:Protein Sorting Signals; D017434:Protein Structure, Tertiary; D021381:Protein Transport / Q000502:physiology*; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D016415:Sequence Alignment; D013572:Synaptic Vesicles / Q000378:metabolism*; D062805:Synaptogyrins
D029742:Caenorhabditis elegans Proteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D021382:Protein Sorting Signals; D011993:Recombinant Fusion Proteins; D062805:Synaptogyrins; C423186:UNC-104 protein, C elegans