mRNA stability changes precede changes in steady-state mRNA amounts during hyperosmotic stress

• Under stress, cells need to optimize the activity of a wide range of gene products during the response phases: shock, adaptation, and recovery. This requires coordination of several levels of regulation, including turnover and translation efficiencies ofmRNAs. Mitogen-activated protein (MAP) kinase pathways are implicated in many aspects of the environmental stress response,including initiation of transcription, translation efficiency, and mRNA turnover. In this study, we analyze mRNA turnover ratesand mRNA steady-state levels at different time points following mild hyperosmotic shock in Saccharomyces cerevisiae cells. Theregulation of mRNA stability is transient and affects most genes for which there is a change in transcript level. These changesprecede and prepare for the changes in steady-state levels, both regarding the initial increase and the later decline of stressinducedmRNAs. The inverse is true for stress-repressed genes, which become stabilized during hyperosmotic stress inpreparation of an increase as the cells recover. The MAP kinase Hog1 affects both steady-state levels and stability of stressresponsivetranscripts, whereas Rck2 influences steady-state levels without a major effect on stability. Regulation of mRNAstability is a wide-spread, but not universal, effect on stress-responsive transcripts during transient hyperosmotic stress. Bydestabilizing stress-induced mRNAs when their steady-state levels have reached a maximum, the cell prepares for thesubsequent recovery phase when these transcripts are to return to normal levels. Conversely, stabilization of stress-repressedmRNAs permits their rapid accumulation in the recovery phase. Our results show that mRNA turnover is coordinated withtranscriptional induction.

Ämnesord

NATURVETENSKAP  -- Biologi -- Biokemi och molekylärbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Biochemistry and Molecular Biology (hsv//eng)

NATURVETENSKAP  -- Biologi -- Annan biologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Other Biological Topics (hsv//eng)

NATURVETENSKAP  -- Biologi -- Bioinformatik och systembiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Bioinformatics and Systems Biology (hsv//eng)

Nyckelord

Saccharomyces cerevisiae

mRNA turnover

HOG pathway

stress-activated MAP kinase

mRNA turnover; Saccharomyces cerevisiae; stress-activated MAP kinase; HOG pathway

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