| Structural highlights
Disease
FANCJ_HUMAN Defects in BRIP1 are a cause of susceptibility to breast cancer (BC) [MIM:114480. A common malignancy originating from breast epithelial tissue. Breast neoplasms can be distinguished by their histologic pattern. Invasive ductal carcinoma is by far the most common type. Breast cancer is etiologically and genetically heterogeneous. Important genetic factors have been indicated by familial occurrence and bilateral involvement. Mutations at more than one locus can be involved in different families or even in the same case.[1] [2] [3] [4] Defects in BRIP1 are the cause of Fanconi anemia complementation group J (FANCJ) [MIM:609054. It is a disorder affecting all bone marrow elements and resulting in anemia, leukopenia and thrombopenia. It is associated with cardiac, renal and limb malformations, dermal pigmentary changes, and a predisposition to the development of malignancies. At the cellular level it is associated with hypersensitivity to DNA-damaging agents, chromosomal instability (increased chromosome breakage) and defective DNA repair.[5] [6] [7] [8] [9]
Function
FANCJ_HUMAN DNA-dependent ATPase and 5' to 3' DNA helicase required for the maintenance of chromosomal stability. Acts late in the Fanconi anemia pathway, after FANCD2 ubiquitination. Involved in the repair of DNA double-strand breaks by homologous recombination in a manner that depends on its association with BRCA1.[10] [11] [12] [13]
Publication Abstract from PubMed
Guanine-rich nucleic acid sequences can fold into G-quadruplex (G4) structures that regulate DNA replication, transcription, and translation. Fanconi anemia group J helicase (FANCJ) resolves G4 structures at stalled replication forks. Despite its central role in genome maintenance, the molecular basis of G4 recognition and unwinding by FANCJ has remained unclear. Here, we report cryo-EM structures of human FANCJ bound to a G4-containing DNA substrate and ATPgammaS. The structures reveal direct engagement of the G4 by the Fe-S domain. Structure-guided mutagenesis demonstrates that this interface is essential for G4 binding and unwinding. The structures further capture open and closed conformational states linked to ATP hydrolysis, providing a mechanism for directional translocation along 5' ssDNA and progressive G4 unwinding. Together, these findings establish the structural basis of G4 recognition by FANCJ and provide mechanistic insights into how disease-associated mutations linked to Fanconi anemia and breast cancer impair helicase function.
Cryo-EM structures of human FANCJ reveal the mechanism of G-quadruplex unwinding and disease-associated mutations.,You Q, Kakusho N, Sasanuma H, Masai H, Li H Nat Commun. 2026 Jul 15. doi: 10.1038/s41467-026-75715-0. PMID:42457705[14]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Cantor SB, Bell DW, Ganesan S, Kass EM, Drapkin R, Grossman S, Wahrer DC, Sgroi DC, Lane WS, Haber DA, Livingston DM. BACH1, a novel helicase-like protein, interacts directly with BRCA1 and contributes to its DNA repair function. Cell. 2001 Apr 6;105(1):149-60. PMID:11301010
- ↑ Cantor S, Drapkin R, Zhang F, Lin Y, Han J, Pamidi S, Livingston DM. The BRCA1-associated protein BACH1 is a DNA helicase targeted by clinically relevant inactivating mutations. Proc Natl Acad Sci U S A. 2004 Feb 24;101(8):2357-62. PMID:14983014
- ↑ Litman R, Peng M, Jin Z, Zhang F, Zhang J, Powell S, Andreassen PR, Cantor SB. BACH1 is critical for homologous recombination and appears to be the Fanconi anemia gene product FANCJ. Cancer Cell. 2005 Sep;8(3):255-65. PMID:16153896 doi:S1535-6108(05)00262-X
- ↑ Bridge WL, Vandenberg CJ, Franklin RJ, Hiom K. The BRIP1 helicase functions independently of BRCA1 in the Fanconi anemia pathway for DNA crosslink repair. Nat Genet. 2005 Sep;37(9):953-7. Epub 2005 Aug 21. PMID:16116421 doi:10.1038/ng1627
- ↑ Litman R, Peng M, Jin Z, Zhang F, Zhang J, Powell S, Andreassen PR, Cantor SB. BACH1 is critical for homologous recombination and appears to be the Fanconi anemia gene product FANCJ. Cancer Cell. 2005 Sep;8(3):255-65. PMID:16153896 doi:S1535-6108(05)00262-X
- ↑ Bridge WL, Vandenberg CJ, Franklin RJ, Hiom K. The BRIP1 helicase functions independently of BRCA1 in the Fanconi anemia pathway for DNA crosslink repair. Nat Genet. 2005 Sep;37(9):953-7. Epub 2005 Aug 21. PMID:16116421 doi:10.1038/ng1627
- ↑ Wu Y, Sommers JA, Suhasini AN, Leonard T, Deakyne JS, Mazin AV, Shin-Ya K, Kitao H, Brosh RM Jr. Fanconi anemia group J mutation abolishes its DNA repair function by uncoupling DNA translocation from helicase activity or disruption of protein-DNA complexes. Blood. 2010 Nov 11;116(19):3780-91. doi: 10.1182/blood-2009-11-256016. Epub 2010 , Jul 16. PMID:20639400 doi:10.1182/blood-2009-11-256016
- ↑ Levran O, Attwooll C, Henry RT, Milton KL, Neveling K, Rio P, Batish SD, Kalb R, Velleuer E, Barral S, Ott J, Petrini J, Schindler D, Hanenberg H, Auerbach AD. The BRCA1-interacting helicase BRIP1 is deficient in Fanconi anemia. Nat Genet. 2005 Sep;37(9):931-3. Epub 2005 Aug 21. PMID:16116424 doi:10.1038/ng1624
- ↑ Levitus M, Waisfisz Q, Godthelp BC, de Vries Y, Hussain S, Wiegant WW, Elghalbzouri-Maghrani E, Steltenpool J, Rooimans MA, Pals G, Arwert F, Mathew CG, Zdzienicka MZ, Hiom K, De Winter JP, Joenje H. The DNA helicase BRIP1 is defective in Fanconi anemia complementation group J. Nat Genet. 2005 Sep;37(9):934-5. Epub 2005 Aug 21. PMID:16116423 doi:ng1625
- ↑ Cantor SB, Bell DW, Ganesan S, Kass EM, Drapkin R, Grossman S, Wahrer DC, Sgroi DC, Lane WS, Haber DA, Livingston DM. BACH1, a novel helicase-like protein, interacts directly with BRCA1 and contributes to its DNA repair function. Cell. 2001 Apr 6;105(1):149-60. PMID:11301010
- ↑ Cantor S, Drapkin R, Zhang F, Lin Y, Han J, Pamidi S, Livingston DM. The BRCA1-associated protein BACH1 is a DNA helicase targeted by clinically relevant inactivating mutations. Proc Natl Acad Sci U S A. 2004 Feb 24;101(8):2357-62. PMID:14983014
- ↑ Litman R, Peng M, Jin Z, Zhang F, Zhang J, Powell S, Andreassen PR, Cantor SB. BACH1 is critical for homologous recombination and appears to be the Fanconi anemia gene product FANCJ. Cancer Cell. 2005 Sep;8(3):255-65. PMID:16153896 doi:S1535-6108(05)00262-X
- ↑ Bridge WL, Vandenberg CJ, Franklin RJ, Hiom K. The BRIP1 helicase functions independently of BRCA1 in the Fanconi anemia pathway for DNA crosslink repair. Nat Genet. 2005 Sep;37(9):953-7. Epub 2005 Aug 21. PMID:16116421 doi:10.1038/ng1627
- ↑ You Q, Kakusho N, Sasanuma H, Masai H, Li H. Cryo-EM structures of human FANCJ reveal the mechanism of G-quadruplex unwinding and disease-associated mutations. Nat Commun. 2026 Jul 15. PMID:42457705 doi:10.1038/s41467-026-75715-0
|
