The Fanconi Anemia Pathway Promotes Replication-Dependent DNA Interstrand Cross-Link Repair
Puck Knipscheer,1
Markus Räschle,2
Agata Smogorzewska,3,4,*
Milica Enoiu,5
The Vinh Ho,6
Orlando D. Schärer,5,6
Stephen J. Elledge,3
Johannes C. Walter1,
Fanconi anemia is a human cancer predisposition syndrome caused
by mutations in 13
Fanc genes. The disorder is characterized
by genomic instability and cellular hypersensitivity to chemicals
that generate DNA interstrand cross-links (ICLs). A central
event in the activation of the Fanconi anemia pathway is the
mono-ubiquitylation of the FANCI-FANCD2 complex, but how this
complex confers ICL resistance remains enigmatic. Using a cell-free
system, we showed that FANCI-FANCD2 is required for replication-coupled
ICL repair in S phase. Removal of FANCD2 from extracts inhibits
both nucleolytic incisions near the ICL and translesion DNA
synthesis past the lesion. Reversal of these defects requires
ubiquitylated FANCI-FANCD2. Our results show that multiple steps
of the essential S-phase ICL repair mechanism fail when the
Fanconi anemia pathway is compromised.
2 Department of Molecular Cell Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany.
3 Department of Genetics, Harvard Medical School, and Division of Genetics, Brigham and Women’s Hospital, Boston, MA 02115, USA.
4 Department of Pathology, Massachusetts General Hospital, Boston, MA 02114, USA.
5 Institute of Molecular Cancer Research, University of Zurich, 8057 Zurich, Switzerland.
6 Departments of Pharmacological Sciences and Chemistry, Stony Brook University, Stony Brook, NY 11794, USA.
* Present address: Laboratory of Genome Maintenance, The Rockefeller University, New York, NY 10021, USA.
To whom correspondence should be addressed. E-mail: johannes_walter{at}hms.harvard.edu
