Histone H2AX and Fanconi anemia FANCD2 function in the same pathway to maintain chromosome stability.
Fanconi anemia (FA) is a chromosome fragility syndrome characterized by bone marrow failure and cancer susceptibility. The central FA protein FANCD2 is known to relocate to chromatin upon DNA damage in a poorly understood process. Here, we have induced subnuclear accumulation of DNA damage to prove that histone H2AX is a novel component of the FA/BRCA pathway in response to stalled replication forks. Analyses of cells from H2AX knockout mice or expressing a nonphosphorylable H2AX (H2AX(S136A/S139A)) indicate that phosphorylated H2AX (gammaH2AX) is required for recruiting FANCD2 to chromatin at stalled replication forks. FANCD2 binding to gammaH2AX is BRCA1-dependent and cells deficient or depleted of H2AX show an FA-like phenotype, including an excess of chromatid-type chromosomal aberrations and hypersensitivity to MMC. This MMC hypersensitivity of H2AX-deficient cells is not further increased by depleting FANCD2, indicating that H2AX and FANCD2 function in the same pathway in response to DNA damage-induced replication blockage. Consequently, histone H2AX is functionally connected to the FA/BRCA pathway to resolve stalled replication forks and prevent chromosome instability.
Bogliolo
Massimo
M
Group of Mutagenesis, Department of Genetics and Microbiology, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.
Lyakhovich
Alex
A
Callén
Elsa
E
Castellà
Maria
M
Cappelli
Enrico
E
Ramírez
María J
MJ
Creus
Amadeu
A
Marcos
Ricard
R
Kalb
Reinhard
R
Neveling
Kornelia
K
Schindler
Detlev
D
Surrallés
Jordi
J
D000818:Animals; D019313:BRCA1 Protein / Q000235:genetics / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D002460:Cell Line; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D043171:Chromosomal Instability / Q000187:drug effects / Q000528:radiation effects; D004249:DNA Damage; D004261:DNA Replication / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects; D052236:Fanconi Anemia Complementation Group D2 Protein / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D051856:Fanconi Anemia Complementation Group Proteins / Q000235:genetics / Q000378:metabolism; D005434:Flow Cytometry; D006367:HeLa Cells; D006657:Histones / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D006801:Humans; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D051379:Mice; D018345:Mice, Knockout; D016685:Mitomycin / Q000494:pharmacology; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D014466:Ultraviolet Rays
D019313:BRCA1 Protein; D052236:Fanconi Anemia Complementation Group D2 Protein; D051856:Fanconi Anemia Complementation Group Proteins; C468783:H2AX protein, human; D006657:Histones; D019384:Nucleic Acid Synthesis Inhibitors; D016685:Mitomycin