[대학원 생명과학과 세미나 안내]
연사 : 허동혁 박사(University of Oxford)
연제 : RNA Pol II phosphatase and histone deacetylase mediated surveillance mechanism controls suppression of cryptic antisense transcription to ensure genomic stability.
일시 : 2019년 12월 17일 (화) 오후 4시
장소 : 하나과학관 A동 207호
초청교수 : 윤철원 교수
Abstract
Phosphorylation of the RNA polymerase II C-terminal domain on heptad Y1S2P3T4S5P6S7 coordinates key events during transcription and when its deregulation leads to defects in transcription and RNA processing. Here we report that histone deacetylase complex activity of the fission yeast Hos2/Set3 complex plays an important role in suppressing cryptic initiation of the antisense transcription from gene terminator regions when the C-terminal domain phosphorylation is dysregulated due to the loss of Ssu72 phosphatase. Interestingly, while single hos2/set3 mutants have no effect, loss of hos2 or set3 in addition to Ssu72 leads to dramatic additive increase in antisense transcription globally and correlates with increases genomic instability and formation of deleterious R-loop structures across these regions. We propose that phosphatase activity of Ssu72 is essential to suppress initiation of cryptic transcription in the 3’end of the RNA polymerase II transcribed regions by dephosphorylating Ser5 of RNA polymerase II assembled on the opposite strand. In the absence of Ssu72, antisense transcription is supressed by the Hos2/Set3 dependent surveillance mechanism to maintain genome stability.