UNC-2 CaV2 Channel Localization at Presynaptic Active Zones Depends on UNC-10/RIM and SYD-2/Liprin-α inCaenorhabditis elegans
| Autor: | Mia Krout, Kelly H. Oh, Janet E. Richmond, Hongkyun Kim |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
0301 basic medicine
Scaffold protein Mutant Presynaptic Terminals Neurotransmission Synaptic Transmission Exocytosis 03 medical and health sciences 0302 clinical medicine Animals Active zone Caenorhabditis elegans Caenorhabditis elegans Proteins Research Articles biology Voltage-dependent calcium channel Chemistry Binding protein General Neuroscience Calcium channel fungi Membrane Proteins biology.organism_classification Cell biology Synaptic vesicle exocytosis 030104 developmental biology Intercellular Signaling Peptides and Proteins Carrier Proteins 030217 neurology & neurosurgery Presynaptic active zone Genetic screen |
| Zdroj: | J Neurosci |
| ISSN: | 1529-2401 0270-6474 |
| DOI: | 10.1523/jneurosci.0076-21.2021 |
| Popis: | Presynaptic active zone proteins couple calcium influx with synaptic vesicle exocytosis. However, the control of presynaptic calcium channel clustering by active zone proteins is not completely understood. In aC. elegansforward genetic screen, we find that UNC-10/RIM (Rab3-interacting molecule) and SYD-2/Liprin-αregulate presynaptic clustering of UNC-2, the CaV2 channel ortholog. We further quantitatively analyzed live animals using endogenously GFP-tagged UNC-2 and active zone components. Consistent with the interaction between RIM and CaV2 in mammals, the intensity and number of UNC-2 channel clusters at presynaptic terminals were greatly reduced inunc-10mutant animals. To understand how SYD-2 regulates presynaptic UNC-2 channel clustering, we analyzed presynaptic localization of endogenous SYD-2, UNC-10, RIMB-1/RIM-BP (RIM binding protein), and ELKS-1. Our analysis revealed that while SYD-2 is the most critical for active zone assembly, loss of SYD-2 function does not completely abolish presynaptic localization of UNC-10, RIMB-1, and ELKS-1, suggesting an existence of SYD-2-independent active zone assembly. UNC-2 localization analysis in double and triple mutants of active zone components show that SYD-2 promotes UNC-2 clustering by partially controlling UNC-10 localization, and ELKS-1 and RIMB-1 also contribute to UNC-2 channel clustering. In addition, we find that core active zone proteins are unequal in their abundance. While the abundance of UNC-10 at the active zone is comparable to UNC-2, SYD-2 and ELKS-1 are twice more and RIMB-1 four times more abundant than UNC-2. Together our data show that UNC-10, SYD-2, RIMB-1, and ELKS-1 control presynaptic UNC-2 channel clustering in redundant yet distinct manners.Significance StatementPrecise control of neurotransmission is dependent on the tight coupling of the calcium influx through voltage-gated calcium channels (VGCCs) to the exocytosis machinery at the presynaptic active zones. However, how these VGCCs are tethered to the active zone is incompletely understood. To understand the mechanism of presynaptic VGCC localization, we performed aC. elegansforward genetic screen and quantitatively analyzed endogenous active zones and presynaptic VGCCs. In addition to RIM (Rab3-interacting molecule), our study finds that SYD-2/Liprin-αis critical for presynaptic localization of VGCCs. Yet, the loss of SYD-2, the master active zone scaffolding protein, does not completely abolish the presynaptic localization of the VGCC, showing that the active zone is a resilient structure assembled by redundant mechanisms. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|