Hot topic: Conformational plasticity in the selectivity filter of the TRPV2 ion channel

The TRPV2 ion channel is the less well-characterised relative of the TRPV1 or vanilloid receptor that is activated by capsaicin. TRPV2 channels have many similarities to the TRPV1 channels, in that they are homotetrameric and respond to some of the same ligands (natural products such as cannabinoids) as well as being triggered at elevated temperatures. This study (1) focusses on a different common feature of the whole Transient Receptor Potential family, which are often described as non-selective cation channels. Using comparative analysis of crystals structures in which calcium is bound with and without an agonist, resiniferatoxin, present. The authors suggest that this agonist evokes a symmetrical opening of a selectivity filter gate, which permits increased permeation of calcium ions and also larger organic cations, such as the dye Yo-PRO-1.

Comments by Steve Alexander (@mqzspa)

(1) Zubcevic L et al. (2018). Conformational plasticity in the selectivity filter of the TRPV2 ion channel. Nat Struc Mol Biol., 25:405-415. doi:10.1038/s41594-018-0059-z. [Abstract]