Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1993 Dec 1;90(23):11167-71.
doi: 10.1073/pnas.90.23.11167.

Tyrosine phosphorylation of mammalian RNA polymerase II carboxyl-terminal domain

Affiliations

Tyrosine phosphorylation of mammalian RNA polymerase II carboxyl-terminal domain

R Baskaran et al. Proc Natl Acad Sci U S A. .

Abstract

The carboxyl-terminal domain (CTD) of the largest subunit of RNA polymerase II is composed of tandem repeats of the consensus sequence Tyr-Ser-Pro-Thr-Ser-Pro-Ser. Phosphorylation of the CTD occurs during formation of the initiation complex and is correlated with the transition from complex assembly to elongation. Previously, serine and threonine residues within the CTD have been shown to be modified by the addition of phosphate and by the addition of O-linked GlcNAc. Our results establish that the CTD is also modified in vivo by phosphorylation on tyrosine. Furthermore, a nuclear tyrosine kinase encoded by the c-abl protooncogene phosphorylates the CTD to a high stoichiometry in vitro. Under conditions of maximum phosphorylation, approximately 30 mol of phosphate are incorporated per mol of CTD. The observation that the CTD is not phosphorylated by c-Src tyrosine kinase under identical conditions indicates that the CTD is not a substrate of all tyrosine kinases. Phosphorylation of tyrosine residues within the CTD may modulate the interaction of RNA polymerase II with the preinitiation complex and, hence, may be important in regulating gene expression.

PubMed Disclaimer

Comment in

  • A positive addition to a negative tail's tale.
    Greenleaf AL. Greenleaf AL. Proc Natl Acad Sci U S A. 1993 Dec 1;90(23):10896-7. doi: 10.1073/pnas.90.23.10896. Proc Natl Acad Sci U S A. 1993. PMID: 7504285 Free PMC article. Review. No abstract available.

Similar articles

Cited by

References

    1. J Biol Chem. 1982 Nov 25;257(22):13181-4 - PubMed
    1. Curr Opin Genet Dev. 1993 Feb;3(1):35-43 - PubMed
    1. Mol Cell Biol. 1985 Dec;5(12):3640-3 - PubMed
    1. J Biol Chem. 1986 Oct 25;261(30):14219-25 - PubMed
    1. Proc Natl Acad Sci U S A. 1986 Nov;83(21):8191-5 - PubMed

Publication types

MeSH terms

LinkOut - more resources