Project description:The MAP kinase Sty1 of fission yeast accumulates in the nucleus upon stress, and stimulates expression of hundreds of genes, including atf1, via the constitutively nuclear transcription factor Atf1. The role on transcription of the signal-dependent phosphorylation of Atf1 by Sty1 is unclear. We have expressed the transcription factor and mutant derivatives from a constitutive promoter, to unchain Atf1 activity from its protein levels. Expression of a non-phosphorylatable Atf1 renders cells sensitive to oxidative stress, due to the impaired transcription of a subset of genes, those dependent on another transcription factor, Pap1. Cells expressing a phospho-mimicking mutant display enhanced resistance to stress, and while expression of the Pap1-dependent genes is still stress-dependent, a second subset of genes is constitutively expressed. Our study demonstrates that phosphorylation of Atf1 by Sty1 does not stimulate binding of the transcription factor to DNA but rather establishes a platform of interaction with the transcriptional machinery.
Project description:Analysis of splicing defects in Schizosaccharomyces pombe upon chemical genetic inhibition of splicing kinases dsk1, lkh1, and prp4, as well as alanine-mutation of phosphorylated residues in the splicing factors bpb1, prp2, rsd1, srp1, srp2, usp101, usp103, sum3, prp22, cdc5, and cwf22. This study shows the splicing kinase dsk1 modulates splicing efficiency of introns with non-consensus splice sites, likely through phosphorylation of bpb1. Modulation of splicing efficiency of transcripts through kinase signaling pathways may afford the necessary flexibility to tune the gene expression profile in response to environmental and developmental cues.
Project description:The exploration of cooperative bindings of two transcription factors by ChIP-seq of Atf1-Rst2 binding during glucose starvation in Schizosaccharomyces pombe.
Project description:Phospho-site mutants of the RNA Polymerase II C-terminal domain alter subtelomeric gene expression and chromatin modification state in fission yeast
