Yeast respond to hypotonic shock with a calcium pulse.
We have used the transgenic AEQUORIN calcium reporter system to monitor the cytosolic calcium ([Ca2+]cyt) response of Saccharomyces cerevisiae to hypotonic shock. Such a shock generates an almost immediate and transient rise in [Ca2+]cyt which is eliminated by gadolinium, a blocker of stretch-activated channels. In addition, this transient rise in [Ca2+]cyt is initially insensitive to 1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA), an extracellular calcium chelator. However, BAPTA abruptly attenuates the maintenance of that transient rise. These data show that hypotonic shock generates a stretch-activated channel-dependent calcium pulse in yeast. They also suggest that the immediate calcium influx is primarily generated from intracellular stores, and that a sustained increase in [Ca2+]cyt depends upon extracellular calcium.
Batiza
A F
AF
Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
Schulz
T
T
Masson
P H
PH
D000331:Aequorin / Q000235:genetics / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers; D003600:Cytosol / Q000378:metabolism*; D005682:Gadolinium / Q000494:pharmacology; D017930:Genes, Reporter; D009997:Osmotic Pressure; D011994:Recombinant Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D015290:Second Messenger Systems; D015398:Signal Transduction; D013997:Time Factors
D002121:Calcium Channel Blockers; D011994:Recombinant Proteins; D000331:Aequorin; D005682:Gadolinium; D002118:Calcium