| Autor: |
Görzer, Irene, Schüller, Christoph, Heidenreinch, Erich, Krupanska, Ludmila, Kuchler, Karl, Wintersberger, Ulrike |
| Předmět: |
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| Zdroj: |
Molecular Microbiology; Nov2003, Vol. 50 Issue 4, p1155-1171, 17p |
| Abstrakt: |
A mutational analysis of the essential nuclear actin-related protein of Saccharomyces cerevisiae, Act3p/Arp4p, was performed. The five residues chosen for substitution were amino acids conserved between actin and Act3p/Arp4p, the tertiary structure of which most probably resembles that of actin. Two thermosensitive (ts) mutants, a single and a double point mutant, and one lethal double point mutant were obtained. Both ts mutants were formamide-sensitive which supports a structural relatedness of Act3p/Arp4p to actin; they were also hypersensitive against hydroxyurea and ultraviolet irradiation pointing to a possible role of Act3p/Arp4p in DNA replication and repair. Their ‘suppressor of Ty’ (SPT) phenotype, ob-served with another ts mutant of Act3p/Arp4p before, suggested involvement of Act3p/Arp4p in transcription regulation. Accordingly, genome-wide expression profiling revealed misregulated transcription in a ts mutant of a number of genes, among which increased expression of various stress-responsive genes (many of them requiring Msn2p/Msn4p for induction) was the most salient result. This provides an explanation for the mutant's enhanced resistance to severe thermal and oxidative stress. Thus, Act3p/Arp4p takes an important part in the repression of stress-induced genes under non-stress conditions. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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