Linked Life Data

11284007

Source:http://linkedlifedata.com/resource/pubmed/id/11284007

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2001-4-3
pubmed:abstractText
For the adaptation of cells of Saccharomyces cerevisiae, a period of latency is necessary before exponential growth is resumed in a medium supplemented with a highly inhibitory concentration of copper. In this work, we have examined some physiological responses occurring during this period of adaptation. The results revealed that plasma membrane H(+)-ATPase (PM-ATPase) activity is strongly stimulated (up to 24-fold) during copper-induced latency in growth medium with glucose, reaching maximal levels when the cells were about to start inhibited exponential growth. This in vivo activation of the ATPase activity by copper was accompanied by the stimulation of the H(+)-pumping activity of the enzyme in vivo and was essentially due to the increase of the apparent V(max) for MgATP. Although the exact molecular basis of the reported plasma membrane ATPase activation was not clarified, no increase in the mRNA levels from the encoding genes PMA1 and PMA2 was apparently detected during copper-induced latency. The physiological response reported here may allow the cells to cope with copper-induced lipid peroxidation and consequent decrease in plasma membrane lipid ordering and increase in the non-specific permeability to protons. The consequences of these copper deleterious effects were revealed by the decrease of the intracellular pH (pH(i)) of the yeast population, from approximately pH(i) 6 to pH(i) 5, during copper-induced latency in growth medium at pH 4.3. The time-dependent patterns of plasma membrane ATPase activation and of the decrease of pH(i) during the period of adaptation to growth with copper correlate, suggesting that the regulation of this membrane enzyme activity may be triggered by intracellular acidification. Consistent with this idea, when exponential growth under copper stress was resumed and the pH(i) of the yeast population recovered up to physiological values, plasma membrane ATPase activity simultaneously decreased from the highly stimulated level attained during the adaptation period of latency.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0749-503X
pubmed:author
pubmed:copyrightInfo
Copyright 2001 John Wiley & Sons, Ltd.
pubmed:issnType
Print
pubmed:volume
18
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
511-21
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
The activity of plasma membrane H(+)-ATPase is strongly stimulated during Saccharomyces cerevisiae adaptation to growth under high copper stress, accompanying intracellular acidification.
pubmed:affiliation
Centro de Engenharia Biológica e Química, Instituto Superior Técnico, 1049-001 Lisboa, Portugal.
pubmed:publicationType
Journal Article