Heat-shock response in Schizosaccharomyces pombe cells lacking cyclic AMP-dependent phosphorylation.
Heat sensitivity at 48 degrees C was determined in log-phase cultures of control and pka1-disrupted cells of the fission yeast Schizosaccharomyces pombe grown at 25 degrees C. Cells devoid of protein kinase A exhibited a considerable heat-shock resistance as compared to control cells. Addition of cAMP to control cells prompted a further decrease in viability during heat shock. This effect was not observed with pka1-disrupted cells, suggesting that cAMP-dependent phosphorylation is involved in modulation of the heat-shock response. When control or pka1-disrupted cells were grown at 25 degrees C and then shifted to 37 degrees C they acquired thermo-tolerance to a subsequent treatment at 48 degrees C both in the absence and in the presence of exogenous cAMP. Inhibition of protein synthesis during the adaptive treatment did not block the development of thermo-tolerance. However, the arrest in translation significantly prevented trehalose accumulation in control cells but only slightly affected trehalose increase in pka1-disrupted cells. These data indicate that heat resistance may be established in growing cells of S. pombe by at least two independent post-translational mechanisms: a decrease in cAMP-dependent protein phosphorylation and a hitherto unknown process which may be independent of trehalose accumulation.
Fernández
J
J
Department of Genetics and Microbiology, Facultad de Biologia, University of Murcia, 30071 Murcia, Spain.
Soto
T
T
Vicente-Soler
J
J
Cansado
J
J
Gacto
M
M
D002352:Carrier Proteins / Q000235:genetics; D000242:Cyclic AMP / Q000494:pharmacology / Q000502:physiology*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D005964:Glucosyltransferases / Q000235:genetics; D018869:Heat-Shock Response / Q000235:genetics*; D047908:Intracellular Signaling Peptides and Proteins; D009693:Nucleic Acid Hybridization; D010766:Phosphorylation; D014176:Protein Biosynthesis; D011499:Protein Processing, Post-Translational; D012331:RNA, Fungal / Q000235:genetics; D012568:Schizosaccharomyces / Q000235:genetics* / Q000378:metabolism*; D014158:Transcription, Genetic; D014199:Trehalose / Q000378:metabolism
D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D012331:RNA, Fungal; C015482:protein kinase modulator; D014199:Trehalose; D000242:Cyclic AMP; D005964:Glucosyltransferases; C099692:trehalose synthase; C023180:trehalose-6-phosphate synthase; D017868:Cyclic AMP-Dependent Protein Kinases