High impact information on atf1

• Deletion of the atf1+ gene results in many, but not all, of the phenotypes associated with loss of Sty1, including sensitivity to environmental stress and inability to undergo sexual conjugation [1].
• Schizosaccharomyces pombe atf1+ encodes a transcription factor required for sexual development and entry into stationary phase [2].
• Accordingly, upf1Delta and csx1Delta strains are similarly sensitive to oxidative stress, and the effects of the mutations are not additive, suggesting that Upf1 and Csx1 work in the same pathway to stabilize atf1(+) mRNA during oxidative stress [3].
• Upstream activation site 1 (UAS1), located approximately 900 bp from the transcriptional start site, resembles a cAMP response element (CRE) that is the binding site for the atf1-pcr1 heterodimeric transcriptional activator [4].
• This surprising finding is explained by the observation that ctt1+ basal expression is unaffected in atf1 single mutant and spc1 atf1 double mutant cells, suggesting that unphosphorylated Atf1 represses ctt1+ expression in spc1 cells [5].

Biological context of atf1

• Deletion of atf1 or pcr1 alone has little effect on silencing at the mating-type region, but when combined with RNAi mutants, double mutants fail to nucleate heterochromatin assembly [6].
• Nucleotide depletion or DNA damage as occurs in cdc22-M45 mutant cells, or during hydroxyurea or camptothecin treatment, is sufficient to activate hsp16 expression through atf1 [7].
• Schizosaccharomyces pombe gad7+ encodes a phosphoprotein with a bZIP domain, which is required for proper G1 arrest and gene expression under nitrogen starvation [8].
• The deduced gad7 gene product was a bZIP protein of 566 amino acids, which could bind to the CRE (cAMP response element) sequence in vitro [8].

Associations of atf1 with chemical compounds

• The pmp3 null mutant, as well as the spc1 and atf1 mutants, is hypersensitive to the cationic antibiotic hygromycin B [9].
• Accordingly, a delta atf1 mutant is known to exhibit osmosensitivity for growth, since one of the targets of Atf1 is the gpd1+ gene, which is responsible for the osmoadaptive glycerol production mediated by the Sty1 MAPK cascade [10].
• A Transcription Factor Cascade Involving Fep1 and the CCAAT-Binding Factor Php4 Regulates Gene Expression in Response to Iron Deficiency in the Fission Yeast Schizosaccharomyces pombe [11].

Other interactions of atf1

• Moreover, deletion of atf1 or pcr1 in combination with cenH deletion causes loss of silencing and heterochromatin formation [6].

References