Physical and functional crosstalk between Fanconi anemia core components and the GINS replication complex.
Fanconi anemia (FA) is an inherited disease characterized by bone marrow failure, increased cancer risk and hypersensitivity to DNA cross-linking agents, implying a role for this pathway in the maintenance of genomic stability. The central player of the FA pathway is the multi-subunit E3 ubiquitin ligase complex activated through a replication- and DNA damage-dependent mechanism. A consequence of the activation of the complex is the monoubiquitylation of FANCD2 and FANCI, late term effectors in the maintenance of genome integrity. The details regarding the coordination of the FA-dependent response and the DNA replication process are still mostly unknown. We found, by yeast two-hybrid assay and co-immunoprecipitation in human cells, that the core complex subunit FANCF physically interacts with PSF2, a member of the GINS complex essential for both the initiation and elongation steps of DNA replication. In HeLa cells depleted for PSF2, we observed a decreased binding to chromatin of the FA core complex, suggesting that the GINS complex may have a role in either loading or stabilizing the FA core complex onto chromatin. Consistently, GINS and core complex bind chromatin contemporarily upon origin firing and PSF2 depletion sensitizes cells to DNA cross-linking agents. However, depletion of PSF2 is not sufficient to reduce monoubiquitylation of FANCD2 or its localization to nuclear foci following DNA damage. Our results suggest a novel crosstalk between DNA replication and the FA pathway.
Dipartimento di Scienze Biomolecolari e Biotecnologie, Universita' degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy.
Emanuela
E
Tumini
Paolo
P
Plevani
Marco
M
Muzi-Falconi
Federica
F
Marini
D002843:Chromatin / Q000235:genetics / Q000502:physiology; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism*; D004249:DNA Damage; D004261:DNA Replication; D005199:Fanconi Anemia / Q000235:genetics / Q000378:metabolism*; D052236:Fanconi Anemia Complementation Group D2 Protein / Q000235:genetics / Q000378:metabolism*; D052219:Fanconi Anemia Complementation Group F Protein / Q000235:genetics / Q000378:metabolism*; D051856:Fanconi Anemia Complementation Group Proteins / Q000235:genetics / Q000378:metabolism; D042822:Genomic Instability; D006367:HeLa Cells; D006801:Humans; D047468:Immunoprecipitation; D011485:Protein Binding; D020798:Two-Hybrid System Techniques; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism; D054875:Ubiquitination
D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; C499905:FANCD2 protein, human; C499901:FANCF protein, human; C519921:FANCI protein, human; D052236:Fanconi Anemia Complementation Group D2 Protein; D052219:Fanconi Anemia Complementation Group F Protein; D051856:Fanconi Anemia Complementation Group Proteins; C556406:GINS2 protein, human; D044767:Ubiquitin-Protein Ligases