RNAP II CTD tyrosine 1 performs diverse functions in vertebrate cells

  1. Jing-Ping Hsin
  2. Wencheng Li
  3. Mainul Hoque
  4. Bin Tian
  5. James L Manley  Is a corresponding author
  1. Columbia University, United States
  2. Rutgers University New Jersey Medical School, United States

Abstract

The RNA polymerase II largest subunit (Rpb1) contains a unique C-terminal domain (CTD) that plays multiple roles during transcription. The CTD is composed of consensus Y1S2P3T4S5P6S7 repeats, in which Ser, Thr and Tyr residues can all be phosphorylated. Here we report analysis of CTD Tyr1 using genetically tractable chicken DT40 cells. Cells expressing an Rpb1 derivative with all Tyr residues mutated to Phe (Rpb1-Y1F) were inviable. Remarkably, Rpb1-Y1F was unstable, degraded to a CTD-less form; however stability, but not cell viability, was fully rescued by restoration of a single C-terminal Tyr (Rpb1-25F+Y). Cytoplasmic and nucleoplasmic Rpb1 was phosphorylated exclusively on Tyr1, and phosphorylation specifically of Tyr1 prevented CTD degradation by the proteasome in vitro. Tyr1 phosphorylation was also detected on chromatin-associated, hyperphosphorylated Rpb1, consistent with a role in transcription. Indeed, we detected accumulation of upstream antisense (ua) RNAs in Rpb1-25F+Y cells, indicating a role for Tyr1 in uaRNA expression.

Article and author information

Author details

  1. Jing-Ping Hsin

    Columbia University, New York, United States
    Competing interests
    No competing interests declared.
  2. Wencheng Li

    Rutgers University New Jersey Medical School, Newark, United States
    Competing interests
    No competing interests declared.
  3. Mainul Hoque

    Rutgers University New Jersey Medical School, Newark, United States
    Competing interests
    No competing interests declared.
  4. Bin Tian

    Rutgers University New Jersey Medical School, Newark, United States
    Competing interests
    No competing interests declared.
  5. James L Manley

    Columbia University, New York, United States
    For correspondence
    jlm2@columbia.edu
    Competing interests
    James L Manley, Senior Editor, eLife.

Copyright

© 2014, Hsin et al.

This article is distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use and redistribution provided that the original author and source are credited.

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  1. Jing-Ping Hsin
  2. Wencheng Li
  3. Mainul Hoque
  4. Bin Tian
  5. James L Manley
(2014)
RNAP II CTD tyrosine 1 performs diverse functions in vertebrate cells
eLife 3:e02112.
https://doi.org/10.7554/eLife.02112

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https://doi.org/10.7554/eLife.02112

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