title: Ca(2+) homeostasis in the budding yeast Saccharomyces cerevisiae: Impact of ER/Golgi Ca(2+) storage.
abstract: Yeast has proven to be a powerful tool to elucidate the molecular aspects of several biological processes in higher eukaryotes. As in mammalian cells, yeast intracellular Ca(2+) signalling is crucial for a myriad of biological processes. Yeast cells also bear homologs of the major components of the Ca(2+) signalling toolkit in mammalian cells, including channels, co-transporters and pumps. Using yeast single- and multiple-gene deletion strains of various plasma membrane and organellar Ca(2+) transporters, combined with manipulations to estimate intracellular Ca(2+) storage, we evaluated the contribution of individual transport systems to intracellular Ca(2+) homeostasis. Yeast strains lacking Pmr1 and/or Cod1, two ion pumps implicated in ER/Golgi Ca(2+) homeostasis, displayed a fragmented vacuolar phenotype and showed increased vacuolar Ca(2+) uptake and Ca(2+) influx across the plasma membrane. In the pmr1Δ strain, these effects were insensitive to calcineurin activity, independent of Cch1/Mid1 Ca(2+) channels and Pmc1 but required Vcx1. By contrast, in the cod1Δ strain increased vacuolar Ca(2+) uptake was not affected by Vcx1 deletion but was largely dependent on Pmc1 activity. Our analysis further corroborates the distinct roles of Vcx1 and Pmc1 in vacuolar Ca(2+) uptake and point to the existence of not-yet identified Ca(2+) influx pathways.
authors.affiliation: The Yeast Hub Lab, KU Leuven, Campus Kulak, Etienne Sabbelaan 53, 8500 Kortrijk, Belgium.
authors.forename: Petra
authors.initials: P
authors.lastname: D'hooge
authors.affiliation: Functional Biology, Department of Biology, KU Leuven, Kasteelpark Arenberg 31, 3001 Heverlee, Belgium.
authors.forename: Catherina
authors.initials: C
authors.lastname: Coun
authors.affiliation: The Yeast Hub Lab, KU Leuven, Campus Kulak, Etienne Sabbelaan 53, 8500 Kortrijk, Belgium.
authors.forename: Vincent
authors.initials: V
authors.lastname: Van Eyck
authors.affiliation: The Yeast Hub Lab, KU Leuven, Campus Kulak, Etienne Sabbelaan 53, 8500 Kortrijk, Belgium.
authors.forename: Liesbeth
authors.initials: L
authors.lastname: Faes
authors.affiliation: Functional Biology, Department of Biology, KU Leuven, Kasteelpark Arenberg 31, 3001 Heverlee, Belgium.
authors.forename: Ruben
authors.initials: R
authors.lastname: Ghillebert
authors.affiliation: The Yeast Hub Lab, KU Leuven, Campus Kulak, Etienne Sabbelaan 53, 8500 Kortrijk, Belgium.
authors.forename: Lore
authors.initials: L
authors.lastname: Mariën
authors.affiliation: Functional Biology, Department of Biology, KU Leuven, Kasteelpark Arenberg 31, 3001 Heverlee, Belgium. Electronic address: joris.winderickx@bio.kuleuven.be.
authors.forename: Joris
authors.initials: J
authors.lastname: Winderickx
authors.affiliation: The Yeast Hub Lab, KU Leuven, Campus Kulak, Etienne Sabbelaan 53, 8500 Kortrijk, Belgium. Electronic address: geert.callewaert@med.kuleuven.be.
authors.forename: Geert
authors.initials: G
authors.lastname: Callewaert
mesh_terms: D000331:Aequorin / Q000737:chemistry / Q000378:metabolism; D017920:Antiporters / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism; D000252:Calcium-Transporting ATPases / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000378:metabolism; D018832:Molecular Chaperones / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D014617:Vacuoles / Q000378:metabolism
chemical_list: D017920:Antiporters; C108765:CCH1 protein, S cerevisiae; C468122:COG4 protein, S cerevisiae; D015220:Calcium Channels; C090463:MID1 protein, S cerevisiae; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D018832:Molecular Chaperones; C101767:SSC1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C099946:VCX1 protein, S cerevisiae; D000331:Aequorin; D000252:Calcium-Transporting ATPases; D002118:Calcium
keywords: Calcium homeostasis; ER; Golgi; Saccharomyces cerevisiae; Vacuole