title: Coupling of a voltage-gated Ca2+channel homologue with a plasma membrane H+-ATPase in yeast.
abstract: Yeast has a homologue of mammalian voltage-gated Ca2+channels (VGCCs), enabling the efficient uptake of Ca2+. It comprises two indispensable subunits, Cch1 and Mid1, equivalent to the mammalian pore-forming α1and auxiliary α2/δ subunits, respectively. Unlike the physiological roles of Cch1/Mid1 channels, the regulatory mechanisms of the yeast VGCC homologue remain unclear. Therefore, we screened candidate proteins that interact with Mid1 by an unbiased proteomic approach and identified a plasma membrane H+-ATPase, Pma1, as a candidate. Mid1 coimmunoprecipitated with Pma1, and Mid1-EGFP colocalized with Pma1-mCherry at the plasma membrane. The physiological relevance of their interaction was determined using the temperature-sensitive mutant, pma1-10. At the nonpermissive temperature, the membrane potential was less negative and Ca2+uptake was lower in pma1-10 than in wild-type cells. Increased extracellular H+increased the rate of Ca2+uptake. Therefore, H+extrusion by Pma1 may be important for Ca2+influx through Cch1/Mid1. These results suggest that Pma1 interacts physically with Cch1/Mid1 Ca2+channels to enhance their activity via its H+-pumping activity.
authors.affiliation: Department of Biology, Tokyo Gakugei University, 4-1-1 Nukui kita-machi, Koganei-shi, Tokyo, 184-8501, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Cho
authors.affiliation: Department of Biology, Tokyo Gakugei University, 4-1-1 Nukui kita-machi, Koganei-shi, Tokyo, 184-8501, Japan.
authors.forename: Aya
authors.initials: A
authors.lastname: Ishii-Kato
authors.affiliation: Division of Membrane Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, 444-8787, Japan.|Department of Physiological Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, 444-8787, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Fukata
authors.affiliation: Department of Biology, Tokyo Gakugei University, 4-1-1 Nukui kita-machi, Koganei-shi, Tokyo, 184-8501, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Nakayama
authors.affiliation: Laboratory of Biomembrane, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya, Tokyo, 156-8506, Japan.
authors.forename: Kazuko
authors.initials: K
authors.lastname: Iida
authors.affiliation: Division of Membrane Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, 444-8787, Japan.|Department of Physiological Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, 444-8787, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Fukata
authors.affiliation: Department of Biology, Tokyo Gakugei University, 4-1-1 Nukui kita-machi, Koganei-shi, Tokyo, 184-8501, Japan.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Iida
mesh_terms: D000595:Amino Acid Sequence; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000235:genetics / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D025941:Protein Interaction Mapping / Q000379:methods; D040901:Proteomics; D006180:Proton-Translocating ATPases / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C108765:CCH1 protein, S cerevisiae; D015220:Calcium Channels; C090463:MID1 protein, S cerevisiae; D008562:Membrane Glycoproteins; D029701:Saccharomyces cerevisiae Proteins; C092477:PMA1 protein, S cerevisiae; D006180:Proton-Translocating ATPases; D002118:Calcium