Structural basis of the Munc13-1/Ca2+-Calmodulin interaction: A novel 1-26 calmodulin binding motif with a bipartite binding modeStructural basis of the Munc13-1/Ca2+-Calmodulin interaction: A novel 1-26 calmodulin binding motif with a bipartite binding mode

Structural highlights

2kdu is a 2 chain structure with sequence from Rattus norvegicus and Xenopus laevis. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:Solution NMR
Ligands:
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

CALM1_XENLA Calmodulin mediates the control of a large number of enzymes, ion channels and other proteins by Ca(2+). Among the enzymes to be stimulated by the calmodulin-Ca(2+) complex are a number of protein kinases and phosphatases.

Evolutionary Conservation

 

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

Ca(2+) signalling in neurons through calmodulin (CaM) has a prominent function in regulating synaptic vesicle trafficking, transport, and fusion. Importantly, Ca(2+)-CaM binds a conserved region in the priming proteins Munc13-1 and ubMunc13-2 and thus regulates synaptic neurotransmitter release in neurons in response to residual Ca(2+) signals. We solved the structure of Ca(2+)(4)-CaM in complex with the CaM-binding domain of Munc13-1, which features a novel 1-5-8-26 CaM-binding motif with two separated mobile structural modules, each involving a CaM domain. Photoaffinity labelling data reveal the same modular architecture in the complex with the ubMunc13-2 isoform. The N-module can be dissociated with EGTA to form the half-loaded Munc13/Ca(2+)(2)-CaM complex. The Ca(2+) regulation of these Munc13 isoforms can therefore be explained by the modular nature of the Munc13/Ca(2+)-CaM interactions, where the C-module provides a high-affinity interaction activated at nanomolar [Ca(2+)](i), whereas the N-module acts as a sensor at micromolar [Ca(2+)](i). This Ca(2+)/CaM-binding mode of Munc13 likely constitutes a key molecular correlate of the characteristic Ca(2+)-dependent modulation of short-term synaptic plasticity.

Modular architecture of Munc13/calmodulin complexes: dual regulation by Ca2+ and possible function in short-term synaptic plasticity.,Rodriguez-Castaneda F, Maestre-Martinez M, Coudevylle N, Dimova K, Junge H, Lipstein N, Lee D, Becker S, Brose N, Jahn O, Carlomagno T, Griesinger C EMBO J. 2010 Feb 3;29(3):680-91. Epub 2009 Dec 10. PMID:20010694[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Rodriguez-Castaneda F, Maestre-Martinez M, Coudevylle N, Dimova K, Junge H, Lipstein N, Lee D, Becker S, Brose N, Jahn O, Carlomagno T, Griesinger C. Modular architecture of Munc13/calmodulin complexes: dual regulation by Ca2+ and possible function in short-term synaptic plasticity. EMBO J. 2010 Feb 3;29(3):680-91. Epub 2009 Dec 10. PMID:20010694 doi:10.1038/emboj.2009.373
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