title: FANCJ/BRIP1 recruitment and regulation of FANCD2 in DNA damage responses.
abstract: FANCJ/BRIP1 encodes a helicase that has been implicated in the maintenance of genomic stability. Here, to better understand FANCJ function in DNA damage responses, we have examined the regulation of its cellular localization. FANCJ nuclear foci assemble spontaneously during S phase and are induced by various stresses. FANCJ foci colocalize with the replication fork following treatment with hydroxyurea, but not spontaneously. Using FANCJ mutants, we find that FANCJ helicase activity and the capacity to bind BRCA1 are both involved in FANCJ recruitment. Given similarities to the recruitment of another Fanconi anemia protein, FANCD2, we tested for colocalization of FANCJ and FANCD2. Importantly, these proteins show substantial colocalization, and FANCJ promotes the assembly of FANCD2 nuclear foci. This process is linked to the proper localization of FANCJ itself since both FANCJ and FANCD2 nuclear foci are compromised by FANCJ mutants that abrogate its helicase activity or interaction with BRCA1. Our results suggest that FANCJ is recruited in response to replication stress and that FANCJ/BRIP1 may serve to link FANCD2 to BRCA1.
authors.affiliation: Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Research Foundation, 3333 Burnet Ave. ML S7.203, Cincinnati, OH 45229, USA.
authors.forename: Fan
authors.initials: F
authors.lastname: Zhang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Fan
authors.forename: Keqin
authors.initials: K
authors.lastname: Ren
authors.forename: Arleen D
authors.initials: AD
authors.lastname: Auerbach
authors.forename: Paul R
authors.initials: PR
authors.lastname: Andreassen
mesh_terms: D019313:BRCA1 Protein / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism; D004249:DNA Damage; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005199:Fanconi Anemia / Q000235:genetics / Q000378:metabolism*; D052236:Fanconi Anemia Complementation Group D2 Protein / Q000235:genetics / Q000378:metabolism*; D051856:Fanconi Anemia Complementation Group Proteins; D042822:Genomic Instability; D006801:Humans; D011485:Protein Binding; D021381:Protein Transport; D020365:RNA Helicases / Q000235:genetics / Q000378:metabolism*
chemical_list: D019313:BRCA1 Protein; D004268:DNA-Binding Proteins; D052236:Fanconi Anemia Complementation Group D2 Protein; D051856:Fanconi Anemia Complementation Group Proteins; C000618935:BRIP1 protein, human; D020365:RNA Helicases