Our hosting provider is investigating network issues. We apologize for the inconvenience.

Searching across hundreds of databases

Our searching services are busy right now. Your search will reload in five seconds.

X
Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.

Role for the Ssu72 C-terminal domain phosphatase in RNA polymerase II transcription elongation.

The RNA polymerase II (RNAP II) transcription cycle is accompanied by changes in the phosphorylation status of the C-terminal domain (CTD), a reiterated heptapeptide sequence (Y(1)S(2)P(3)T(4)S(5)P(6)S(7)) present at the C terminus of the largest RNAP II subunit. One of the enzymes involved in this process is Ssu72, a CTD phosphatase with specificity for serine-5-P. Here we report that the ssu72-2-encoded Ssu72-R129A protein is catalytically impaired in vitro and that the ssu72-2 mutant accumulates the serine-5-P form of RNAP II in vivo. An in vitro transcription system derived from the ssu72-2 mutant exhibits impaired elongation efficiency. Mutations in RPB1 and RPB2, the genes encoding the two largest subunits of RNAP II, were identified as suppressors of ssu72-2. The rpb1-1001 suppressor encodes an R1281A replacement, whereas rpb2-1001 encodes an R983G replacement. This information led us to identify the previously defined rpb2-4 and rpb2-10 alleles, which encode catalytically slow forms of RNAP II, as additional suppressors of ssu72-2. Furthermore, deletion of SPT4, which encodes a subunit of the Spt4-Spt5 early elongation complex, also suppresses ssu72-2, whereas the spt5-242 allele is suppressed by rpb2-1001. These results define Ssu72 as a transcription elongation factor. We propose a model in which Ssu72 catalyzes serine-5-P dephosphorylation subsequent to addition of the 7-methylguanosine cap on pre-mRNA in a manner that facilitates the RNAP II transition into the elongation stage of the transcription cycle.

Pubmed ID: 17101794 RIS Download

Mesh terms: Alanine | Alleles | Amino Acid Sequence | Arginine | Carrier Proteins | Chromosomal Proteins, Non-Histone | DNA, Fungal | Models, Genetic | Molecular Sequence Data | Nuclear Proteins | Phenotype | Phosphoprotein Phosphatases | Protein Binding | Protein Structure, Secondary | RNA Polymerase II | Saccharomyces cerevisiae | Saccharomyces cerevisiae Proteins | Sequence Analysis, DNA | Suppression, Genetic | TATA-Binding Protein Associated Factors | Transcription Factor TFIID | Transcription, Genetic | Transcriptional Elongation Factors | mRNA Cleavage and Polyadenylation Factors

Research resources used in this publication

None found

Research tools detected in this publication

None found

Data used in this publication

None found

Associated grants

  • Agency: NIGMS NIH HHS, Id: R25 GM058389
  • Agency: NIGMS NIH HHS, Id: R01 GM039484
  • Agency: NIGMS NIH HHS, Id: GM 55145
  • Agency: NIGMS NIH HHS, Id: T32 GM008360
  • Agency: NIGMS NIH HHS, Id: R01 GM 68887
  • Agency: NIGMS NIH HHS, Id: R01 GM068887
  • Agency: NIGMS NIH HHS, Id: R25 GM055145
  • Agency: NIGMS NIH HHS, Id: R01 GM 39484
  • Agency: NIGMS NIH HHS, Id: GM 008360
  • Agency: NIGMS NIH HHS, Id: GM 58389

Publication data is provided by the National Library of Medicine ® and PubMed ®. Data is retrieved from PubMed ® on a weekly schedule. For terms and conditions see the National Library of Medicine Terms and Conditions.

We have not found any resources mentioned in this publication.