Identification of UHRF2 as a novel DNA interstrand crosslink sensor protein.

Anna Motnenko,Bao Zhan,Chih-Chao Liang,Benedikt M Kessler,Wilhelm Haas,Skirmantas Kriaucionis,Jiayang Tian,Steven P Gygi,Di Yang,David Lopez-Martinez,Yasunaga Yoshikawa,Katherine E Ward,Paolo Spingardi,Martin A Cohn,Julian E Sale

doi:10.1371/journal.pgen.1007643

Anna Motnenko, Bao Zhan + Show 13 more

Open Access

https://doi.org/10.1371/journal.pgen.1007643

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Abstract

The Fanconi Anemia (FA) pathway is important for repairing interstrand crosslinks (ICLs) between the Watson-Crick strands of the DNA double helix. An initial and essential stage in the repair process is the detection of the ICL. Here, we report the identification of UHRF2, a paralogue of UHRF1, as an ICL sensor protein. UHRF2 is recruited to ICLs in the genome within seconds of their appearance. We show that UHRF2 cooperates with UHRF1, to ensure recruitment of FANCD2 to ICLs. A direct protein-protein interaction is formed between UHRF1 and UHRF2, and between either UHRF1 and UHRF2, and FANCD2. Importantly, we demonstrate that the essential monoubiquitination of FANCD2 is stimulated by UHRF1/UHRF2. The stimulation is mediating by a retention of FANCD2 on chromatin, allowing for its monoubiquitination by the FA core complex. Taken together, we uncover a mechanism of ICL sensing by UHRF2, leading to FANCD2 recruitment and retention at ICLs, in turn facilitating activation of FANCD2 by monoubiquitination.

Highlights

DNA interstrand crosslinks (ICLs) can obstruct the critical processes of transcription and replication [1]
UHRF2 has been implicated in genome maintenance as it has been shown to interact with PCNA through a PIP box motif [16], UHRF2 was shown to be recruited to DNA damage sites, primarily through its TandemTudor domain (TTD)-Plant Homeodomain (PHD) and SET and Really Interesting New Gene domain (RING) associated domain (SRA) domains [17]
We previously found UHRF1 to interact directly with ICLs both in vitro and in vivo, we decided to investigate whether UHRF2 might possess similar properties

Summary

Introduction

DNA interstrand crosslinks (ICLs) can obstruct the critical processes of transcription and replication [1]. An ICL can perturb accurate chromosome segregation during mitosis when replication has not been completed due to the crosslink, this can lead to replication fork collapse causing double strand DNA breaks. For these reasons, repair of ICLs is required to preserve genomic stability. UHRF2 has been implicated in genome maintenance as it has been shown to interact with PCNA through a PIP box motif [16], UHRF2 was shown to be recruited to DNA damage sites, primarily through its TTD-PHD and SRA domains [17]

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