Open AccessHIR1 , the co‐repressor of histone gene transcription of Saccharomyces cerevisiae , acts as a multicopy suppressor of the apoptotic phenotypes of the LSM4 mRNA degradation mutant
Author(s) -
Mazzoni Cristina,
Palermo Vanessa,
Torella Mirko,
Falcone Claudio
Publication year - 2005
Publication title -
fems yeast research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.991
H-Index - 92
eISSN - 1567-1364
pISSN - 1567-1356
DOI - 10.1016/j.femsyr.2005.07.007
Subject(s) - biology , mutant , gene , microbiology and biotechnology , repressor , histone , transcription (linguistics) , saccharomyces cerevisiae , dna fragmentation , gene expression , dna , genetics , programmed cell death , apoptosis , philosophy , linguistics
We previously have reported that Saccharomyces cerevisiae mutants expressing Kllsm4Δ1 , a truncated form of the KlLSM4 gene, as well as mutants in genes of the mRNA‐decapping pathway, show phenotypic markers of apoptosis, increased temperature sensitivity and reduced growth in the presence of different drugs and oxidative stressing agents, such as acetic acid and H 2 O 2 . To isolate multicopy extra‐genic suppressors of these defects, we transformed the Kllsm4Δ1 mutant with a yeast DNA library and we selected a series of clones showing resistance to acetic acid. One of these clones carried a DNA fragment containing the HIR1 gene that encodes a transcriptional co‐repressor of histone genes. The over‐expression of HIR1 in the Kllsm4Δ1 mutant prevented rapid cell death during chronological aging, reduced nuclei fragmentation and increased resistance to H 2 O 2 . Transcription analysis revealed that the expression of histone genes was lowered in the mutant over‐expressing HIR1 , indicating a relationship between the latter gene and apoptosis.