Open AccessCatSper and Two-Pore channels (TPC) in GtoPdb v.2022.1
Author(s) -
Jean-Ju Chung,
David E. Clapham,
David L. Garbers,
Christian Grimm,
Dejian Ren
Publication year - 2022
Publication title -
iuphar/bps guide to pharmacology cite
Language(s) - English
Resource type - Journals
ISSN - 2633-1020
DOI - 10.2218/gtopdb/f70/2022.1
Subject(s) - microbiology and biotechnology , voltage dependent calcium channel , patch clamp , chemistry , ion channel , lytechinus variegatus , biology , biophysics , calcium , sea urchin , biochemistry , receptor , organic chemistry
CatSper channels (CatSper1-4, nomenclature as agreed by NC-IUPHAR [14]) are putative 6TM, voltage-gated, alkalinization-activated calcium permeant channels that are presumed to assemble as a tetramer of α-like subunits and mediate the current ICatSper [23]. In mammals, CatSper subunits are structurally most closely related to individual domains of voltage-activated calcium channels (Cav) [40]. CatSper1 [40], CatSper2 [37] and CatSpers 3 and 4 [27, 21, 36], in common with a putative 2TM auxiliary CatSperβ protein [26] and two putative 1TM associated CatSperγ and CatSperδ proteins [46, 12], are restricted to the testis and localised to the principle piece of sperm tail. The novel cross-species CatSper channel inhibitor, RU1968, has been proposed as a useful tool to aid characterisation of native CatSper channels [41].Two-pore channels (TPCs) are structurally related to CatSpers, CaVs and NaVs. TPCs have a 2x6TM structure with twice the number of TMs of CatSpers and half that of CaVs. There are three animal TPCs (TPC1-TPC3). Humans have TPC1 and TPC2, but not TPC3. TPC1 and TPC2 are localized in endosomes and lysosomes [5]. TPC3 is also found on the plasma membrane and forms a voltage-activated, non-inactivating Na+ channel [6]. All the three TPCs are Na+-selective under whole-cell or whole-organelle patch clamp recording [48, 8, 7]. The channels may also conduct Ca2+ [31].