Alpha-neurexins couple Ca2+ channels to synaptic vesicle exocytosis |
| |
Authors: | Missler Markus Zhang Weiqi Rohlmann Astrid Kattenstroth Gunnar Hammer Robert E Gottmann Kurt Südhof Thomas C |
| |
Institution: | Center for Basic Neuroscience, Department of Molecular Genetics, Dallas, Texas 75390-9111, USA. |
| |
Abstract: | Synapses are specialized intercellular junctions in which cell adhesion molecules connect the presynaptic machinery for neurotransmitter release to the postsynaptic machinery for receptor signalling. Neurotransmitter release requires the presynaptic co-assembly of Ca2+ channels with the secretory apparatus, but little is known about how synaptic components are organized. Alpha-neurexins, a family of >1,000 presynaptic cell-surface proteins encoded by three genes, link the pre- and postsynaptic compartments of synapses by binding extracellularly to postsynaptic cell adhesion molecules and intracellularly to presynaptic PDZ domain proteins. Using triple-knockout mice, we show that alpha-neurexins are not required for synapse formation, but are essential for Ca2+-triggered neurotransmitter release. Neurotransmitter release is impaired because synaptic Ca2+ channel function is markedly reduced, although the number of cell-surface Ca2+ channels appears normal. These data suggest that alpha-neurexins organize presynaptic terminals by functionally coupling Ca2+ channels to the presynaptic machinery. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|