The Fanconi Anemia Proteins FANCD2 and FANCJ Interact and Regulate Each Other's Chromatin Localization

Xiaoyong Chen,James B Wilson,Patricia Mcchesney,Stacy A Williams,Youngho Kwon,Simonne Longerich,Andrew S Marriott,Patrick Sung,Nigel J Jones,Gary M Kupfer

doi:10.1074/jbc.m114.552570

Xiaoyong Chen, James B Wilson + Show 8 more

Open Access

https://doi.org/10.1074/jbc.m114.552570

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Abstract

Fanconi anemia is a genetic disease resulting in bone marrow failure, birth defects, and cancer that is thought to encompass a defect in maintenance of genomic stability. Mutations in 16 genes (FANCA, B, C, D1, D2, E, F, G, I, J, L, M, N, O, P, and Q) have been identified in patients, with the Fanconi anemia subtype J (FA-J) resulting from homozygous mutations in the FANCJ gene. Here, we describe the direct interaction of FANCD2 with FANCJ. We demonstrate the interaction of FANCD2 and FANCJ in vivo and in vitro by immunoprecipitation in crude cell lysates and from fractions after gel filtration and with baculovirally expressed proteins. Mutation of the monoubiquitination site of FANCD2 (K561R) preserves interaction with FANCJ constitutively in a manner that impedes proper chromatin localization of FANCJ. FANCJ is necessary for FANCD2 chromatin loading and focus formation in response to mitomycin C treatment. Our results suggest not only that FANCD2 regulates FANCJ chromatin localization but also that FANCJ is necessary for efficient loading of FANCD2 onto chromatin following DNA damage caused by mitomycin C treatment.

Highlights

Fanconi anemia (FA) is a genetic disease of birth defects, bone marrow failure, and cancer
Our results suggest that FANCD2 regulates FANCJ chromatin localization and that FANCJ is necessary for efficient loading of FANCD2 onto chromatin following DNA damage caused by mitomycin C treatment
Subsequent immunoblotting against FANCD2 showed that FANCD2 co-precipitated with FANCJ in both the wild type and monoubiquitination mutant cell extracts (Fig. 1A)

Summary

Background

Fanconi anemia (FA) is a genetic disease of birth defects, bone marrow failure, and cancer. Mutation of the monoubiquitination site of FANCD2 (K561R) preserves interaction with FANCJ constitutively in a manner that impedes proper chromatin localization of FANCJ. Our results suggest that FANCD2 regulates FANCJ chromatin localization and that FANCJ is necessary for efficient loading of FANCD2 onto chromatin following DNA damage caused by mitomycin C treatment. Plex,” which includes FANCA, B, C, E, F, G, L, and M, is activated upon activation of the DNA damage response, typically during the S phase (9 –13) This complex translocates from the cytoplasm to the nucleus, where it participates in the monoubiquitination of FANCD2 [14, 15]. FANCJ and FANCD2 regulate each other’s proper chromatin loading

EXPERIMENTAL PROCEDURES

RESULTS

DISCUSSION