7FHK

Structure of AtTPC1 with 1 mM Ca2+

Summary for 7FHK

• Entry DOI: 10.2210/pdb7fhk/pdb
• EMDB information: 31585
• Descriptor: Two pore calcium channel protein 1,GFP, AtTPC1-Cter, CALCIUM ION (3 entities in total)
• Functional Keywords: non-selective cation channel, dimer, vacuole, transport protein
• Biological source: Arabidopsis thaliana (Mouse-ear cress); More
• Total number of polymer chains: 4
• Total formula weight: 231527.45

Authors

Ye, F.,Xu, L.,Li, X.,Jiang, Y.,Guo, J. (deposition date: 2021-07-29, release date: 2021-12-01, Last modification date: 2024-06-12)

Primary citation

Ye, F.,Xu, L.,Li, X.,Zeng, W.,Gan, N.,Zhao, C.,Yang, W.,Jiang, Y.,Guo, J.
Voltage-gating and cytosolic Ca 2+ activation mechanisms of Arabidopsis two-pore channel AtTPC1.
Proc.Natl.Acad.Sci.USA, 118:-, 2021

PubMed Abstract: two-pore channel AtTPC1 is a voltage-gated, Ca-modulated, nonselective cation channel that is localized in the vacuolar membrane and responsible for generating slow vacuolar (SV) current. Under depolarizing membrane potential, cytosolic Ca activates AtTPC1 by binding at the EF-hand domain, whereas luminal Ca 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 Ca-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 Ca activation, and their coupling in AtTPC1. This study also provides structural insight into the general voltage-gating mechanism among voltage-gated ion channels.

PubMed: 34845029
DOI: 10.1073/pnas.2113946118

Experimental method

ELECTRON MICROSCOPY (3.3 Å)