The Ig cell adhesion molecule Basigin controls compartmentalization and vesicle release at Drosophila melanogaster synapses.
Synapses can undergo rapid changes in size as well as in their vesicle release function during both plasticity processes and development. This fundamental property of neuronal cells requires the coordinated rearrangement of synaptic membranes and their associated cytoskeleton, yet remarkably little is known of how this coupling is achieved. In a GFP exon-trap screen, we identified Drosophila melanogaster Basigin (Bsg) as an immunoglobulin domain-containing transmembrane protein accumulating at periactive zones of neuromuscular junctions. Bsg is required pre- and postsynaptically to restrict synaptic bouton size, its juxtamembrane cytoplasmic residues being important for that function. Bsg controls different aspects of synaptic structure, including distribution of synaptic vesicles and organization of the presynaptic cortical actin cytoskeleton. Strikingly, bsg function is also required specifically within the presynaptic terminal to inhibit nonsynchronized evoked vesicle release. We thus propose that Bsg is part of a transsynaptic complex regulating synaptic compartmentalization and strength, and coordinating plasma membrane and cortical organization.
Besse
Florence
F
Developmental Biology Unit, European Molecular Biology Laboratory, D-69117 Heidelberg, Germany.
Mertel
Sara
S
Kittel
Robert J
RJ
Wichmann
Carolin
C
Rasse
Tobias M
TM
Sigrist
Stephan J
SJ
Ephrussi
Anne
A
D008841:Actin Cytoskeleton / Q000378:metabolism / Q000648:ultrastructure; D000595:Amino Acid Sequence; D000818:Animals; D002448:Cell Adhesion; D002451:Cell Compartmentation; D015536:Down-Regulation; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D009154:Mutation; D009469:Neuromuscular Junction / Q000378:metabolism; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D013569:Synapses / Q000378:metabolism / Q000502:physiology*; D013572:Synaptic Vesicles / Q000502:physiology*
C504909:Bsg protein, Drosophila; D029721:Drosophila Proteins; D008562:Membrane Glycoproteins