ISSN:
1617-4623
Keywords:
Key words Stress
;
cAMP
;
SAC1
;
SOK1
;
SCH9
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The MBR1 gene was isolated as a multicopy suppressor of the phenotype on glycerol medium of a Saccharomyces cerevisiae strain mutant for the Hap2/3/4/5 transactivator complex. In this paper, we show that Mbr1p is a limiting factor for growth on glycerol medium under the following sub-optimal culture conditions: in late growth phase, at low temperature, at high external pH or in the presence of 1,10-phenanthroline. Moreover, deletion of MBR1 prot- ects cells against stress, whilst overexpression of this gene has the opposite effect. MBR1 expression is induced in the late growth phase and is negatively controlled by the cAMP-dependent protein kinase A (PKA). Both activation of PKA or overexpression of SOK1 or SCH9– two genes isolated as multicopy suppressors of a PKA null mutant – suppress the mbr1 growth defect. Our results indicate that Mbr1p is not an essential element of any one of these pathways. Deletion of SAC1, a gene implicated in vesicular transport, in association with MBR1 deletion, causes synthetic lethality. A possible role of Mbr1p in intracellular trafficking is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004380050512
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