Activation of divalent cation influx into S. cerevisiae cells by hypotonic downshift.
Subjecting Saccharomyces cerevisiae cells to a hypotonic downshift by transferring cells form YPD medium containing 0.8 M sorbitol to YPD medium without sorbitol induces a transient rapid influx of Ca2+ and other divalent cations into the cell. For cells grown in YPD at 37 degrees C, this hypotonic downshift increases Ca2+ accumulation 6.7-fold. Hypotonic downshift-induced Ca2+ accumulation and steady-state Ca2+ accumulation in isotonic YPD medium are differentially affected by dodecylamine and Mg2+. The Ca(2+)-influx pathway responsible for hypotonic-induced Ca2+ influx may account for about 10-35% of Ca2+ accumulation by cells growing in YPD. Ca2+ influx is not required for cells to survive a hypotonic downshift. Hypotonic downshift greatly reduces the ability of S. cerevisiae cells to survive a 5-min exposure to 10 mM Cd2+ suggesting that mutants resistant to acute Cd2+ exposure may help identify genes required for hypotonic downshift-induced divalent cation influx.
Beeler
T
T
Department of Biochemistry, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814, USA.
Gable
K
K
Dunn
T
T
D000588:Amines / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology / Q000633:toxicity; D002413:Cations, Divalent; D007038:Hypotonic Solutions; D012441:Saccharomyces cerevisiae / Q000378:metabolism*
D000588:Amines; D002413:Cations, Divalent; D007038:Hypotonic Solutions; D002118:Calcium