Rtr1 is Necessary for Ctd-Ser7 Phosphorylation in Vivo

Abstract

Rtr1, and its human orthologue RPAP2, have been described as CTD-Ser5 phosphatases that function in the transition from transcription initiation to elongation. Additional roles for these proteins during RNA polymerase II assembly and transcription termination of non-coding RNAs have also been addressed. We analyse the role of Saccharomyces cerevisiae Rtr1 protein during CTD-Ser7 phosphorylation in this work. We demonstrate that deletion of RTR1 leads to a notable increase in CTD-Ser7P levels, which suggests that Rtr1 is imperative for the proper dephosphorylation of this residue. The data also support a hypothesis that Rtr1 could be a prerequisite for the Ssu72 function as CTD-Ser7P phosphatase.

Keywords: Transcription elongationRtr1CTD phosphorylation