title: P(5A)-type ATPase Cta4p is essential for Ca2+ transport in the endoplasmic reticulum of Schizosaccharomyces pombe.
abstract: This study establishes the role of P(5A)-type Cta4 ATPase in Ca(2+) sequestration in the endoplasmic reticulum by detecting an ATP-dependent, vanadate-sensitive and FCCP insensitive (45)Ca(2+)-transport in fission yeast membranes isolated by cellular fractionation. Specifically, the Ca(2+)-ATPase transport activity was decreased in ER membranes isolated from cells lacking a cta4(+) gene. Furthermore, a disruption of cta4(+) resulted in 6-fold increase of intracellular Ca(2+) levels, sensitivity towards accumulation of misfolded proteins in ER and ER stress, stimulation of the calcineurin phosphatase activity and vacuolar Ca(2+) pumping. These data provide compelling biochemical evidence for a P(5A)-type Cta4 ATPase as an essential component of Ca(2+) transport system and signaling network which regulate, in conjunction with calcineurin, the ER functionality in fission yeast.
authors: Laboratório de Fisiologia e Bioquímica de Microrganismos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Rio de Janeiro, Brazil.
authors: Ana Cristina D M
authors: AC
authors: Lustoza
authors: Livia M
authors: LM
authors: Palma
authors: Arnoldo R
authors: AR
authors: Façanha
authors: Lev A
authors: LA
authors: Okorokov
authors: Anna L
authors: AL
authors: Okorokova-Façanha
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D019703:Calcineurin / Q000378:metabolism; D065095:Calcineurin Inhibitors; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000201:enzymology*; D000091342:Endoplasmic Reticulum Chaperone BiP; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects; D017353:Gene Deletion; D006031:Glycosylation / Q000187:drug effects; D006360:Heat-Shock Proteins / Q000378:metabolism; D007425:Intracellular Membranes / Q000201:enzymology; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D012568:Schizosaccharomyces / Q000166:cytology / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development; D029702:Schizosaccharomyces pombe Proteins / Q000378:metabolism*
chemical_list: D065095:Calcineurin Inhibitors; C459542:Cta4 protein, S pombe; D000091342:Endoplasmic Reticulum Chaperone BiP; D006360:Heat-Shock Proteins; D029702:Schizosaccharomyces pombe Proteins; D000255:Adenosine Triphosphate; D019703:Calcineurin; D000252:Calcium-Transporting ATPases; D002118:Calcium