DNA cross-link repair 1B protein is a protein that in humans is encoded by the DCLRE1Bgene.[1]
DNA interstrand cross-links prevent strand separation, thereby physically blocking transcription, replication, and segregation of DNA. DCLRE1B is one of several evolutionarily conserved genes involved in repair of interstrand cross-links (Dronkert et al., 2000).[supplied by OMIM][1]
Function
The DCLRE1B/SNM1B/Apollo protein is a repair exonuclease that digests double-stranded and single-stranded DNA with a 5’ to 3’ directionality.[2]
In a human patient with Hoyeraal-Hreidarsson syndrome, a dominant negative mutation in the SNM1B/Apollo gene was discovered.[4] This mutation hampered the proper replication of telomeres, leading to major telomeric dysfunction and cellular senescence. SNM1B/Apollo protein appears to be a crucial factor in telomere maintenance, independent of its function in repairing DNA inter-strand crosslinks.[4]
Ota T, Suzuki Y, Nishikawa T, et al. (2004). "Complete sequencing and characterization of 21,243 full-length human cDNAs". Nat. Genet. 36 (1): 40–5. doi:10.1038/ng1285. PMID14702039.
Demuth I, Digweed M, Concannon P (2004). "Human SNM1B is required for normal cellular response to both DNA interstrand crosslink-inducing agents and ionizing radiation". Oncogene. 23 (53): 8611–8. doi:10.1038/sj.onc.1207895. PMID15467758.
Freibaum BD, Counter CM (2006). "hSnm1B is a novel telomere-associated protein". J. Biol. Chem. 281 (22): 15033–6. doi:10.1074/jbc.C600038200. PMID16606622.
Gregory SG, Barlow KF, McLay KE, et al. (2006). "The DNA sequence and biological annotation of human chromosome 1". Nature. 441 (7091): 315–21. doi:10.1038/nature04727. PMID16710414.
Lenain C, Bauwens S, Amiard S, et al. (2006). "The Apollo 5' exonuclease functions together with TRF2 to protect telomeres from DNA repair". Curr. Biol. 16 (13): 1303–10. doi:10.1016/j.cub.2006.05.021. PMID16730175.
van Overbeek M, de Lange T (2006). "Apollo, an Artemis-related nuclease, interacts with TRF2 and protects human telomeres in S phase". Curr. Biol. 16 (13): 1295–302. doi:10.1016/j.cub.2006.05.022. PMID16730176.