title: Synaptic specificity is generated by the synaptic guidepost protein SYG-2 and its receptor, SYG-1.
abstract: Synaptic connections in the nervous system are directed onto specific cellular and subcellular targets. Synaptic guidepost cells in the C. elegans vulval epithelium drive synapses from the HSNL motor neuron onto adjacent target neurons and muscles. Here, we show that the transmembrane immunoglobulin superfamily protein SYG-2 is a central component of the synaptic guidepost signal. SYG-2 is expressed transiently by primary vulval epithelial cells during synapse formation. SYG-2 binds SYG-1, the receptor on HSNL, and directs SYG-1 accumulation and synapse formation to adjacent regions of HSNL. syg-1 and syg-2 mutants have defects in synaptic specificity; the HSNL neuron forms fewer synapses onto its normal targets and forms ectopic synapses onto inappropriate targets. Misexpression of SYG-2 in secondary epithelial cells causes aberrant accumulation of SYG-1 and synaptic markers in HSNL adjacent to the SYG-2-expressing cells. Our results indicate that local interactions between immunoglobulin superfamily proteins can determine specificity during synapse formation.
authors.affiliation: Howard Hughes Medical Institute, Department of Anatomy, The University of California, San Francisco, San Francisco, CA 94143, USA.
authors.forename: Kang
authors.initials: K
authors.lastname: Shen
authors.forename: Richard D
authors.initials: RD
authors.lastname: Fetter
authors.forename: Cornelia I
authors.initials: CI
authors.lastname: Bargmann
mesh_terms: D000595:Amino Acid Sequence / Q000235:genetics; D000818:Animals; D001483:Base Sequence / Q000235:genetics; D017173:Caenorhabditis elegans / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology*; D003463:Cues; D018076:DNA, Complementary / Q000032:analysis / Q000235:genetics; D004847:Epithelial Cells / Q000378:metabolism / Q000648:ultrastructure; D020439:Growth Cones / Q000378:metabolism / Q000648:ultrastructure; D007136:Immunoglobulins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D008969:Molecular Sequence Data; D009414:Nerve Growth Factors / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D009420:Nervous System / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D009434:Neural Pathways / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D013569:Synapses / Q000378:metabolism* / Q000648:ultrastructure; D013572:Synaptic Vesicles / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D029742:Caenorhabditis elegans Proteins; D018076:DNA, Complementary; D007136:Immunoglobulins; D008565:Membrane Proteins; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D011956:Receptors, Cell Surface; C473474:SYG-1 protein, C elegans; C484036:SYG-2 protein, C elegans