Tip60 is required for DNA interstrand cross-link repair in the Fanconi anemia pathway.
The disease Fanconi anemia is a genome instability syndrome characterized by cellular sensitivity to DNA interstrand cross-linking agents, manifest by decreased cellular survival and chromosomal aberrations after such treatment. There are at least 13 proteins acting in the pathway, with the FANCD2 protein apparently functioning as a late term effecter in the maintenance of genome stability. We find that the chromatin remodeling protein, Tip60, interacts directly with the FANCD2 protein in a yeast two-hybrid system. This interaction has been confirmed by co-immunoprecipitation and co-localization using both endogenous and epitope-tagged FANCD2 and Tip60 from human cells. The observation of decreased cellular survival after exposure to mitomycin C in normal fibroblasts depleted for Tip60 indicates a direct function in interstrand cross-link repair. The coincident function of Tip60 and FANCD2 in one pathway is supported by the finding that depletion of Tip60 in Fanconi anemia cells does not increase sensitivity to DNA cross-links. However, depletion of Tip60 did not reduce monoubiquitination of FANCD2 or its localization to nuclear foci following DNA damage. The observations indicate that Fanconi anemia proteins act in concert with chromatin remodeling functions to maintain genome stability after DNA cross-link damage.
Hejna
James
J
Department of Molecular and Medical Genetics, Oregon Health & Science University, 3181 Sam Jackson Parkway, Portland, OR 97239, USA.
Holtorf
Megan
M
Hines
Jennie
J
Mathewson
Lauren
L
Hemphill
Aaron
A
Al-Dhalimy
Muhsen
M
Olson
Susan B
SB
Moses
Robb E
RE
D021581:Active Transport, Cell Nucleus / Q000187:drug effects / Q000235:genetics; D002460:Cell Line; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism*; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D042002:Chromatin Assembly and Disassembly / Q000502:physiology*; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004249:DNA Damage / Q000187:drug effects / Q000235:genetics; D004260:DNA Repair / Q000187:drug effects / Q000502:physiology*; D005199:Fanconi Anemia / Q000235:genetics / Q000378:metabolism; D052236:Fanconi Anemia Complementation Group D2 Protein / Q000235:genetics / Q000378:metabolism*; D042822:Genomic Instability / Q000187:drug effects / Q000235:genetics; D051548:Histone Acetyltransferases / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D000074443:Lysine Acetyltransferase 5; D016685:Mitomycin / Q000494:pharmacology; D054875:Ubiquitination / Q000187:drug effects / Q000502:physiology
D003432:Cross-Linking Reagents; C499905:FANCD2 protein, human; D052236:Fanconi Anemia Complementation Group D2 Protein; D016685:Mitomycin; D051548:Histone Acetyltransferases; C098489:KAT5 protein, human; D000074443:Lysine Acetyltransferase 5