Scc1 sumoylation by Mms21 promotes sister chromatid recombination through counteracting Wapl
- Nan Wu1,
- Xiangduo Kong2,
- Zhejian Ji1,
- Weihua Zeng2,
- Patrick Ryan Potts3,
- Kyoko Yokomori2 and
- Hongtao Yu1,4
- 1Howard Hughes Medical Institute, Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA;
- 2Department of Biological Chemistry, School of Medicine, University of California at Irvine, Irvine, California 92697-1700, USA;
- 3Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
Abstract
DNA double-strand breaks (DSBs) fuel cancer-driving chromosome translocations. Two related structural maintenance of chromosomes (Smc) complexes, cohesin and Smc5/6, promote DSB repair through sister chromatid homologous recombination (SCR). Here we show that the Smc5/6 subunit Mms21 sumoylates multiple lysines of the cohesin subunit Scc1. Mms21 promotes cohesin-dependent small ubiquitin-like modifier (SUMO) accumulation at laser-induced DNA damage sites in S/G2 human cells. Cells expressing the nonsumoylatable Scc1 mutant (15KR) maintain sister chromatid cohesion during mitosis but are defective in SCR and sensitive to ionizing radiation (IR). Scc1 15KR is recruited to DNA damage sites. Depletion of Wapl, a negative cohesin regulator, rescues SCR defects of Mms21-deficient or Scc1 15KR-expressing cells. Expression of the acetylation-mimicking Smc3 mutant does not bypass the requirement for Mms21 in SCR. We propose that Scc1 sumoylation by Mms21 promotes SCR by antagonizing Wapl at a step after cohesin loading at DSBs and in a way not solely dependent on Smc3 acetylation.
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Footnotes
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↵4 Corresponding author
E-mail hongtao.yu{at}utsouthwestern.edu
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Supplemental material is available for this article.
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Article is online at http://www.genesdev.org/cgi/doi/10.1101/gad.193615.112.
- Received April 4, 2012.
- Accepted May 21, 2012.
- Copyright © 2012 by Cold Spring Harbor Laboratory Press
Freely available online through the Genes & Development Open Access option.