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| TPK GENE-PRODUCTS MEDIATE CAMP-INDEPENDENT THERMOTOLERANCE IN SACCHAROMYCES-CEREVISIAE |
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| Author(s): COOTE PJ, JONES MV, EDGAR K, COLE MB |
| Source: JOURNAL OF GENERAL MICROBIOLOGY Volume: 138 Pages: 2551-2557 Part: Part 12 Published: DEC 1992 |
| Times Cited: 12 References: 40 |
| Abstract: Incubation of Saccharomyces cerevisiae with the plant cytokinin N6-(DELTA2-isopentenyl)adenine (2iP) resulted in an induction of thermotolerance similar to that induced by sublethal temperatures. Intracellular cAMP levels did not change significantly either during incubation at a sublethal temperature or in the presence of 2iP or ethanol. This suggested that stress-induced thermotolerance is triggered by a mechanism independent of cAMP activation. However, measurement of stress-induced thermotolerance in two mutant strains (tpk1, tpk2, TPK3; tpk1, TPK2, tpk3) each deficient in two of the catalytic subunits of the cAMP-dependent protein kinase (cAPK), revealed that sublethal heat induces thermotolerance by a mechanism part-mediated by the catalytic subunits of cAPK. In contrast, 2iP and ethanol induced thermotolerance by a mechanism fully dependent on the catalytic subunits of cAPK for expression. Therefore, this implies there must be an alternative novel mechanism, other than cAMP, for activating cAPK during stress. Sublethal heating resulted in large increases in intracellular trehalose levels which correlated with the induction of thermotolerance. However, incubation in 2iP or ethanol had no significant effect. This suggests trehalose synthesis is either coincidental with heat stress or that different stress factors induce thermotolerance by alternative mechanisms. Incubation with protein synthesis inhibitors reduced the levels of trehalose synthesized during sublethal heating, suggesting that synthesis of trehalose-6-phosphate synthase during heat stress could be accounting for the increased trehalose levels. |
| Document Type: Article |
| Language: English |
| Reprint Address: COOTE, PJ (reprint author), UNILEVER RES, COLWORTH LAB, SHARNBROOK MK44 1LQ, BEDS ENGLAND |
| Publisher: SOC GENERAL MICROBIOLOGY, HARVEST HOUSE 62 LONDON ROAD, READING, BERKS, ENGLAND RG1 5AS |
| Subject Category: Microbiology |
| IDS Number: KE264 |
| ISSN: 0022-1287 |
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| |  |  |  |  | | | | Record from Web of Science® | |  |  | | | | | | |