Besse, F. et al. The Ig cell adhesion molecule Basigin controls compartmentalization and vesicle release at Drosophila melanogaster synapses. J. Cell Biol. 177, 843-855

Developmental Biology Unit, European Molecular Biology Laboratory, D-69117 Heidelberg, Germany.
The Journal of Cell Biology (Impact Factor: 9.83). 07/2007; 177(5):843-55. DOI: 10.1083/jcb.200701111
Source: PubMed


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.

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    • "These observations provide an insight into the indispensable role of EMMPRIN in normal CNS physiology. In this context, a study on Drosophila melanogaster showed that EMMPRIN was vital for proper synaptic functioning, including distribution of synaptic vesicles and their release at the neuromuscular junctions [41]. As these findings highlight numerous roles for EMMPRIN in the CNS, it is logical that diseases of the CNS would present with EMMPRIN deregulation. "
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    • "When the BRP immunostaining at the neuromuscular junction was observed with the electron microscope, it appeared exclusively at synapses [12]. Double staining for nc82 and antibodies specific for glutamate receptors defined that practically each BRP-spot (presynaptic side of a single synapse) correlated with a single cluster of glutamate receptors (postsynaptic side of the same synapse) reinforcing the view that anti-BRP alone can be used to obtain a good estimation of synapse numbers [12], [15], [36], [38], [39], [43], [46]–[48], [50]. "
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    • "It might be possible to circumvent this problem through the use of conditional mutants or allelic combinations that bypass early requirements via interallelic complementation. Furthermore, it would be of interest to examine possible known integrin interacting partners such as the Basigin receptor (Besse et al., 2007). Moreover, other ECM receptors reside at the Drosophila NMJ (see below), and it is unknown what happens to their expression and distribution in the absence of Mtg or PS integrin function. "
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