Structural highlights
Function
[TPC1_ARATH] Functions as a voltage-gated inward-rectifying Ca(2+) channel (VDCC) across the vacuole membrane. Is one of the essential components of the slow vacuolar (SV) channel. Acts as the major ROS-responsive Ca(2+) channel and is the possible target of Al-dependent inhibition. Involved in the regulation of germination and stomatal movement.[1] [2]
Publication Abstract from PubMed
Voltage-gated ion channels confer excitability to biological membranes, initiating and propagating electrical signals across large distances on short timescales. Membrane excitation requires channels that respond to changes in electric field and couple the transmembrane voltage to gating of a central pore. To address the mechanism of this process in a voltage-gated ion channel, we determined structures of the plant two-pore channel 1 at different stages along its activation coordinate. These high-resolution structures of activation intermediates, when compared with the resting-state structure, portray a mechanism in which the voltage-sensing domain undergoes dilation and in-membrane plane rotation about the gating charge-bearing helix, followed by charge translocation across the charge transfer seal. These structures, in concert with patch-clamp electrophysiology, show that residues in the pore mouth sense inhibitory Ca(2+) and are allosterically coupled to the voltage sensor. These conformational changes provide insight into the mechanism of voltage-sensor domain activation in which activation occurs vectorially over a series of elementary steps.
Molecular basis of multistep voltage activation in plant two-pore channel 1.,Dickinson MS, Lu J, Gupta M, Marten I, Hedrich R, Stroud RM Proc Natl Acad Sci U S A. 2022 Mar 1;119(9). pii: 2110936119. doi:, 10.1073/pnas.2110936119. PMID:35210362[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Kawano T, Kadono T, Fumoto K, Lapeyrie F, Kuse M, Isobe M, Furuichi T, Muto S. Aluminum as a specific inhibitor of plant TPC1 Ca2+ channels. Biochem Biophys Res Commun. 2004 Nov 5;324(1):40-5. PMID:15464979 doi:http://dx.doi.org/S0006-291X(04)02051-0
- ↑ Peiter E, Maathuis FJ, Mills LN, Knight H, Pelloux J, Hetherington AM, Sanders D. The vacuolar Ca2+-activated channel TPC1 regulates germination and stomatal movement. Nature. 2005 Mar 17;434(7031):404-8. PMID:15772667 doi:http://dx.doi.org/nature03381
- ↑ Dickinson MS, Lu J, Gupta M, Marten I, Hedrich R, Stroud RM. Molecular basis of multistep voltage activation in plant two-pore channel 1. Proc Natl Acad Sci U S A. 2022 Mar 1;119(9). pii: 2110936119. doi:, 10.1073/pnas.2110936119. PMID:35210362 doi:http://dx.doi.org/10.1073/pnas.2110936119
