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  • The EMBO Journal (2006) 25, 2847 - 2855
  • doi:10.1038/sj.emboj.7601178

Published online: 8 June 2006

Controlling the subcellular localization of DNA polymerases iota and eta via interactions with ubiquitin

Brian S Ploskya, Antonio E Vidalab, Antonio R Fernández de Henestrosaac, Mary P McLenigan, John P McDonald, Samantha Mead and Roger Woodgate

  1. Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA

Correspondence to:

Roger Woodgate, Section on DNA Replication, Repair & Mutagenesis, National Institute of Child Health and Human Development, National Institutes of Health, Building 6, Room 1A13, 9000 Rockville Pike, Bethesda, MD 20892-2725, USA. Tel.: +1 301 496 6175; Fax: +1 301 594 1135; E-mail: woodgate@nih.gov

aThese authors contributed equally to this work

bPresent address: Instituto de Parasitologia y Biomedicina, Parque Tecnologico Ciencias de la Salud, Avda. del Conocimiento S/N, 18100 Armilla (Granada), Spain

cPresent address: Department of Toxicology, ESTEVE, Mare de Deu de Montserrat 221, 08041 Barcelona, Spain

Received 21 September 2005; Accepted 12 May 2006

Y-family DNA polymerases have spacious active sites that can accommodate a wide variety of geometric distortions. As a consequence, they are considerably more error-prone than high-fidelity replicases. It is hardly surprising, therefore, that the in vivo activity of these polymerases is tightly regulated, so as to minimize their inadvertent access to primer-termini. We report here that one such mechanism employed by human cells relies on a specific and direct interaction between DNA polymerases iota and eta with ubiquitin (Ub). Indeed, we show that both polymerases interact noncovalently with free polyUb chains, as well as mono-ubiquitinated proliferating cell nuclear antigen (Ub-PCNA). Mutants of poliota (P692R) and poleta (H654A) were isolated that are defective in their interactions with polyUb and Ub-PCNA, whilst retaining their ability to interact with unmodified PCNA. Interestingly, the polymerase mutants exhibit significantly lower levels of replication foci in response to DNA damage, thereby highlighting the biological importance of the polymerase–Ub interaction in regulating the access of the TLS polymerases to stalled replication forks in vivo.

  • Keywords:

    • 26S proteasome,
    • Rad30,
    • translesion replication,
    • Y-family DNA polymerases