| Structural highlights
Function
[TRPV5_RABIT] Constitutively active calcium selective cation channel thought to be involved in Ca(2+) reabsorption in kidney and intestine (PubMed:12574114). Required for normal Ca(2+) reabsorption in the kidney distal convoluted tubules (By similarity). The channel is activated by low internal calcium level and the current exhibits an inward rectification (By similarity). A Ca(2+)-dependent feedback regulation includes fast channel inactivation and slow current decay (By similarity). Heteromeric assembly with TRPV6 seems to modify channel properties. TRPV5-TRPV6 heteromultimeric concatemers exhibit voltage-dependent gating (PubMed:12574114).[UniProtKB:P69744][UniProtKB:Q9NQA5][1] [2] [3]
Publication Abstract from PubMed
TRPV5 is a transient receptor potential channel involved in calcium reabsorption. Here we investigate the interaction of two endogenous modulators with TRPV5. Both phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) and calmodulin (CaM) have been shown to directly bind to TRPV5 and activate or inactivate the channel, respectively. Using cryo-electron microscopy (cryo-EM), we determined TRPV5 structures in the presence of dioctanoyl PI(4,5)P2 and CaM. The PI(4,5)P2 structure reveals a binding site between the N-linker, S4-S5 linker and S6 helix of TRPV5. These interactions with PI(4,5)P2 induce conformational rearrangements in the lower gate, opening the channel. The CaM structure reveals two TRPV5 C-terminal peptides anchoring a single CaM molecule and that calcium inhibition is mediated through a cation-pi interaction between Lys116 on the C-lobe of calcium-activated CaM and Trp583 at the intracellular gate of TRPV5. Overall, this investigation provides insight into the endogenous modulation of TRPV5, which has the potential to guide drug discovery.
Structural insights on TRPV5 gating by endogenous modulators.,Hughes TET, Pumroy RA, Yazici AT, Kasimova MA, Fluck EC, Huynh KW, Samanta A, Molugu SK, Zhou ZH, Carnevale V, Rohacs T, Moiseenkova-Bell VY Nat Commun. 2018 Oct 10;9(1):4198. doi: 10.1038/s41467-018-06753-6. PMID:30305626[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Hoenderop JG, van der Kemp AW, Hartog A, van de Graaf SF, van Os CH, Willems PH, Bindels RJ. Molecular identification of the apical Ca2+ channel in 1, 25-dihydroxyvitamin D3-responsive epithelia. J Biol Chem. 1999 Mar 26;274(13):8375-8. PMID:10085067
- ↑ Nilius B, Vennekens R, Prenen J, Hoenderop JG, Droogmans G, Bindels RJ. The single pore residue Asp542 determines Ca2+ permeation and Mg2+ block of the epithelial Ca2+ channel. J Biol Chem. 2001 Jan 12;276(2):1020-5. PMID:11035011 doi:http://dx.doi.org/10.1074/jbc.M006184200
- ↑ Hoenderop JG, Voets T, Hoefs S, Weidema F, Prenen J, Nilius B, Bindels RJ. Homo- and heterotetrameric architecture of the epithelial Ca2+ channels TRPV5 and TRPV6. EMBO J. 2003 Feb 17;22(4):776-85. PMID:12574114 doi:http://dx.doi.org/10.1093/emboj/cdg080
- ↑ Hughes TET, Pumroy RA, Yazici AT, Kasimova MA, Fluck EC, Huynh KW, Samanta A, Molugu SK, Zhou ZH, Carnevale V, Rohacs T, Moiseenkova-Bell VY. Structural insights on TRPV5 gating by endogenous modulators. Nat Commun. 2018 Oct 10;9(1):4198. doi: 10.1038/s41467-018-06753-6. PMID:30305626 doi:http://dx.doi.org/10.1038/s41467-018-06753-6
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