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  • The EMBO Journal (2002) 21, 6246 - 6256
  • doi:10.1093/emboj/cdf618

Localization of DNA polymerases eta and iota to the replication machinery is tightly co-ordinated in human cells

Patricia Kannouche1, Antonio R. Fernández de Henestrosa2,3, Barry Coull1, Antonio E. Vidal2, Colin Gray4, Daniel Zicha4, Roger Woodgate2 and Alan R. Lehmann1

  1. Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton BN1 9RQ, UK
  2. Section on DNA Replication, Repair and Mutagenesis, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-2725, USA
  3. Present address: Unitat de Microbiologia, Departament de Genètica i de Microbiologia Edifici Cn, Universitat Autònoma de Barcelona, Bellaterra, Barcelona 08193, Spain
  4. Cancer Research UK London Research Institute, 44, Lincoln's Inn Fields, London WC2A 3PX, UK

Correspondence to:

Alan R. Lehmann, E-mail: a.r.lehmann@sussex.ac.uk

Received 15 July 2002; Accepted 1 October 2002; Revised 25 September 2002

Y-family DNA polymerases can replicate past a variety of damaged bases in vitro but, with the exception of DNA polymerase eta (poleta), which is defective in xeroderma pigmentosum variants, there is little information on the functions of these polymerases in vivo. Here, we show that DNA polymerase iota (poliota), like poleta, associates with the replication machinery and accumulates at stalled replication forks following DNA-damaging treatment. We show that poleta and poliota foci form with identical kinetics and spatial distributions, suggesting that localization of these two polymerases is tightly co-ordinated within the nucleus. Furthermore, localization of poliota in replication foci is largely dependent on the presence of poleta. Using several different approaches, we demonstrate that poleta and poliota interact with each other physically and that the C-terminal 224 amino acids of poliota are sufficient for both the interaction with poleta and accumulation in replication foci. Our results provide strong evidence that poleta targets poliota to the replication machinery, where it may play a general role in maintaining genome integrity as well as participating in translesion DNA synthesis.

  • Keywords:

    • DNA polymerase,
    • replication foci,
    • UV light,
    • xeroderma pigmentosum variants