Coupling of a voltage-gated Ca 2+ channel homologue with a plasma membrane H + -ATPase in yeast

Genes Cells. 2017 Jan;22(1):94-104. doi: 10.1111/gtc.12458. Epub 2016 Dec 9.

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 α1 and 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.

MeSH terms

  • Amino Acid Sequence
  • Calcium / metabolism
  • Calcium Channels / genetics
  • Calcium Channels / metabolism*
  • Cell Membrane / genetics
  • Cell Membrane / metabolism
  • Membrane Glycoproteins / genetics
  • Membrane Glycoproteins / metabolism*
  • Protein Interaction Mapping / methods
  • Proteomics*
  • Proton-Translocating ATPases / genetics
  • Proton-Translocating ATPases / metabolism*
  • Saccharomyces cerevisiae
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*

Substances

  • CCH1 protein, S cerevisiae
  • Calcium Channels
  • MID1 protein, S cerevisiae
  • Membrane Glycoproteins
  • Saccharomyces cerevisiae Proteins
  • PMA1 protein, S cerevisiae
  • Proton-Translocating ATPases
  • Calcium