Structural highlights
3dvm is a 2 chain structure with sequence from European rabbit and Human. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
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| Ligands: | |
| Related: | |
| Gene: | CALM1, CALM, CAM, CAM1, CALM2, CAM2, CAMB, CALM3, CALML2, CAM3, CAMC, CAMIII (HUMAN), CACNA1A, CACH4, CACN3, CACNL1A4 (European rabbit) |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
[CAC1A_RABIT] Voltage-sensitive calcium channels (VSCC) mediate the entry of calcium ions into excitable cells and are also involved in a variety of calcium-dependent processes, including muscle contraction, hormone or neurotransmitter release, gene expression, cell motility, cell division and cell death. The isoform alpha-1A gives rise to P and/or Q-type calcium currents. P/Q-type calcium channels belong to the 'high-voltage activated' (HVA) group and are blocked by the funnel toxin (Ftx) and by the omega-agatoxin-IVA (omega-Aga-IVA). They are however insensitive to dihydropyridines (DHP), and omega-conotoxin-GVIA (omega-CTx-GVIA).
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
Calcium influx drives two opposing voltage-activated calcium channel (Ca(V)) self-modulatory processes: calcium-dependent inactivation (CDI) and calcium-dependent facilitation (CDF). Specific Ca(2+)/calmodulin (Ca(2+)/CaM) lobes produce CDI and CDF through interactions with the Ca(V)alpha(1) subunit IQ domain. Curiously, Ca(2+)/CaM lobe modulation polarity appears inverted between Ca(V)1s and Ca(V)2s. Here, we present crystal structures of Ca(V)2.1, Ca(V)2.2, and Ca(V)2.3 Ca(2+)/CaM-IQ domain complexes. All display binding orientations opposite to Ca(V)1.2 with a physical reversal of the CaM lobe positions relative to the IQ alpha-helix. Titration calorimetry reveals lobe competition for a high-affinity site common to Ca(V)1 and Ca(V)2 IQ domains that is occupied by the CDI lobe in the structures. Electrophysiological experiments demonstrate that the N-terminal Ca(V)2 Ca(2+)/C-lobe anchors affect CDF. Together, the data unveil the remarkable structural plasticity at the heart of Ca(V) feedback modulation and indicate that Ca(V)1 and Ca(V)2 IQ domains bear a dedicated CDF site that exchanges Ca(2+)/CaM lobe occupants.
Structures of CaV2 Ca2+/CaM-IQ domain complexes reveal binding modes that underlie calcium-dependent inactivation and facilitation.,Kim EY, Rumpf CH, Fujiwara Y, Cooley ES, Van Petegem F, Minor DL Jr Structure. 2008 Oct 8;16(10):1455-67. PMID:18940602[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Kim EY, Rumpf CH, Fujiwara Y, Cooley ES, Van Petegem F, Minor DL Jr. Structures of CaV2 Ca2+/CaM-IQ domain complexes reveal binding modes that underlie calcium-dependent inactivation and facilitation. Structure. 2008 Oct 8;16(10):1455-67. PMID:18940602 doi:10.1016/j.str.2008.07.010
