scholarly journals Structure of the voltage-gated two-pore channel TPC1 from Arabidopsis thaliana

Nature ◽  
2015 ◽  
Vol 531 (7593) ◽  
pp. 196-201 ◽  
Author(s):  
Jiangtao Guo ◽  
Weizhong Zeng ◽  
Qingfeng Chen ◽  
Changkeun Lee ◽  
Liping Chen ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Pore Channel ◽  
Voltage Gated

scholarly journals On the Structure and Mechanism of Two-Pore Channels

2017 ◽  
Author(s):  
Alexander F. Kintzer ◽  
Robert M. Stroud
Keyword(s):  
Arabidopsis Thaliana ◽  
Protein Kinase ◽  
Channel Structure ◽  
Target Of Rapamycin ◽  
Nutrient Concentrations ◽  
Pore Channel ◽  
Voltage Gated ◽  
Mechanistic Target Of Rapamycin ◽  
Terminal Domain ◽  
Pore Domain

AbstractIn eukaryotes, two-pore channels (TPC1-3) comprise a family of ion channels that regulate the conductance of Na+ and Ca2+ ions across cellular membranes. TPC1-3 form endolysosomal channels, but TPC3 can also function in the plasma membrane. TPC1/3 are voltage-gated channels, but TPC2 opens in response to binding endolysosome-specific lipid phosphatidylinositol-3,5-diphosphate (PI(3,5)P2). Filoviruses, such as Ebola, exploit TPC-mediated ion release as a means of escape from the endolysosome during infection. Antagonists that block TPC1/2 channel conductance abrogate filoviral infections. TPC1/2 form complexes with the mechanistic target of rapamycin complex 1 (mTORC1) at the endolysosomal surface that couple cellular metabolic state and cytosolic nutrient concentrations to the control of membrane potential and pH. We determined the X-ray structure of TPC1 from Arabidopsis thaliana (AtTPC1) to 2.87Å resolution–one of the two first reports of a TPC channel structure. Here we summarize these findings and the implications that the structure may have for understanding endolysosomal control mechanisms and their role in human health.AbbreviationsmTORC1Mechanistic target of rapamycin complex 1TPCTwo-pore channelPI(3,5)P2Phosphatidylinositol-3,5-diphosphateAtTPC1Arabidopsis thaliana TPC1NED19Trans-Ned-19VSDVoltage-sensing domainP1Pore domain in S5-S6P2Pore domain in S11-S12CavVoltage-gated calcium channelNavVoltage-gated sodium channelKvVoltage-gated potassium channelNTDN-terminal domainCTDC-terminal domainEFEF-hand domainNAADPNicotinic acid adenine dinucleotide phosphatePI(4,5)P2Phosphatidylinositol-4,5-diphosphateDHPDihydropyridinePAAPhenylalkylamineBTZBenzothiazepineCaa2+Activating Ca2+-ionCai2+Inhibitory Ca2+-ionfou2Fatty acid oxygenation up-regulated 2SLC38a9Sodium-coupled neutral amino acid transporter 9NPC1Niemann-Pick C1PKAProtein kinase APKCProtein kinase CPKGProtein kinase GH+ATPase - Proton Pump32P– Phosphorus-32

scholarly journals Structure, inhibition and regulation of two-pore channel TPC1 from Arabidopsis thaliana

Nature ◽  
2016 ◽  
Vol 531 (7593) ◽  
pp. 258-264 ◽  
Author(s):  
Alexander F. Kintzer ◽  
Robert M. Stroud
Keyword(s):  
Arabidopsis Thaliana ◽  
Pore Channel

scholarly journals Structure, inhibition and regulation of two-pore channel TPC1 from Arabidopsis thaliana

2016 ◽  
Author(s):  
Alexander F Kintzer ◽  
Robert M Stroud
Keyword(s):  
Arabidopsis Thaliana ◽  
Ebola Virus ◽  
Cytosolic Calcium ◽  
Pore Channel ◽  
Ion Binding ◽  
Voltage Sensitivity ◽  
Voltage Sensing ◽  
Activated State ◽  
Ion Binding Sites ◽  
Voltage Gated Ion Channels

Two-pore channels (TPCs) comprise a subfamily (TPC1-3) of eukaryotic voltage- and ligand-gated cation channels that contain two non-equivalent tandem pore-forming subunits that then dimerize to form quasi-tetramers. Found in vacuolar or endolysosomal membranes, they regulate the conductance of sodium and calcium ions, intravesicular pH, trafficking and excitability. TPCs are activated by a decrease in transmembrane potential, an increase in cytosolic calcium concentrations, and inhibited by luminal low pH, and calcium, and regulated by phosphorylation,. We report the crystal structure of TPC1 from Arabidopsis thaliana (TPC1) at 2.8x4.0x3.3 angstrom resolution as a basis for understanding ion permeation, channel activation, the location of voltage-sensing domains, and regulatory ion-binding sites. We determined sites of phosphorylation in the N-terminal and C-terminal domains that are positioned to allosterically modulate cytoplasmic Ca2+-activation. One of the two voltage sensing domains (VSDII) encodes voltage sensitivity and inhibition by lumenal Ca2+ and adopts a conformation distinct from the activated state observed in structures of other voltage-gated ion channels. The structure shows that potent pharmacophore trans-NED19 allosterically acts by clamping the pore domains to VSDII. In animals NED19 prevents infection by Ebola virus and Filoviruses presumably by altering their fusion with the endolysosome, and delivery of their contents into the cytoplasm.

scholarly journals Resting state structure of the hyperdepolarization activated two-pore channel 3

2020 ◽  
Vol 117 (4) ◽  
pp. 1988-1993
Author(s):  
Miles Sasha Dickinson ◽  
Alexander Myasnikov ◽  
Jacob Eriksen ◽  
Nicole Poweleit ◽  
Robert M. Stroud
Keyword(s):  
Resting State ◽  
Action Potentials ◽  
Pore Channel ◽  
Activation Threshold ◽  
Voltage Gated ◽  
Bona Fide ◽  
Voltage Gated Ion Channels ◽  
Voltage Sensing Domain ◽  
Voltage Activation ◽  
Closed Pore

Voltage-gated ion channels endow membranes with excitability and the means to propagate action potentials that form the basis of all neuronal signaling. We determined the structure of a voltage-gated sodium channel, two-pore channel 3 (TPC3), which generates ultralong action potentials. TPC3 is distinguished by activation only at extreme membrane depolarization (V50 ∼ +75 mV), in contrast to other TPCs and NaV channels that activate between −20 and 0 mV. We present electrophysiological evidence that TPC3 voltage activation depends only on voltage sensing domain 2 (VSD2) and that each of the three gating arginines in VSD2 reduces the activation threshold. The structure presents a chemical basis for sodium selectivity, and a constricted gate suggests a closed pore consistent with extreme voltage dependence. The structure, confirmed by our electrophysiology, illustrates the configuration of a bona fide resting state voltage sensor, observed without the need for any inhibitory ligand, and independent of any chemical or mutagenic alteration.

Voltage-gating and cytosolic Ca2+ activation mechanisms of Arabidopsis two-pore channel AtTPC1

2021 ◽  
Vol 118 (49) ◽  
pp. e2113946118
Author(s):  
Fan Ye ◽  
Lingyi Xu ◽  
Xiaoxiao Li ◽  
Weizhong Zeng ◽  
Ninghai Gan ◽  
...  
Keyword(s):  
Voltage Gating ◽  
Pore Channel ◽  
Voltage Gated ◽  
Gating Mechanism ◽  
Ef Hand ◽  
Activation Mechanisms ◽  
Voltage Gated Ion Channels ◽  
Structural Mechanisms ◽  
Voltage Sensing Domain ◽  
Insight Into

Arabidopsis thaliana two-pore channel AtTPC1 is a voltage-gated, Ca2+-modulated, nonselective cation channel that is localized in the vacuolar membrane and responsible for generating slow vacuolar (SV) current. Under depolarizing membrane potential, cytosolic Ca2+ activates AtTPC1 by binding at the EF-hand domain, whereas luminal Ca2+ inhibits the channel by stabilizing the voltage-sensing domain II (VSDII) in the resting state. Here, we present 2.8 to 3.3 Å cryoelectron microscopy (cryo-EM) structures of AtTPC1 in two conformations, one in closed conformation with unbound EF-hand domain and resting VSDII and the other in a partially open conformation with Ca2+-bound EF-hand domain and activated VSDII. Structural comparison between the two different conformations allows us to elucidate the structural mechanisms of voltage gating, cytosolic Ca2+ activation, and their coupling in AtTPC1. This study also provides structural insight into the general voltage-gating mechanism among voltage-gated ion channels.

Stable genetic transformation of Arabidopsis thaliana by Agrobacterium inoculation in planta

1994 ◽  
Vol 5 (4) ◽  
pp. 551-558 ◽  
Author(s):  
Seok So Chang ◽  
Soon Ki Park ◽  
Byung Chul Kim ◽  
Bong Joong Kang ◽  
Dal Ung Kim ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Genetic Transformation ◽  
In Planta
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