Bloom syndrome protein is a protein that in humans is encoded by the BLMgene and is not expressed in Bloom syndrome.[1]
The Bloom syndrome gene product is related to the RecQ subset of DExH box-containing DNA helicases and has both DNA-stimulated ATPase and ATP-dependent DNA helicase activities. Mutations causing Bloom syndrome delete or alter helicase motifs and may disable the 3' → 5' helicase activity. The normal protein may act to suppress inappropriate homologous recombination.[2]
Recombination during meiosis is often initiated by a DNA double-strand break (DSB). During recombination, sections of DNA at the 5' ends of the break are cut away in a process called resection. In the strand invasion step that follows, an overhanging 3' end of the broken DNA molecule then "invades" the DNA of an homologous chromosome that is not broken. After strand invasion, the further sequence of events may follow either of two main pathways leading to a crossover (CO) or a non-crossover (NCO) recombinant (see Genetic recombination and bottom of Figure in this section).
The budding yeast Saccharomyces cerevisiae encodes an ortholog of the Bloom syndrome (BLM) protein that is designated Sgs1 (Small growth suppressor 1). Sgs1(BLM) is a helicase that functions in homologous recombinational repair of DSBs. The Sgs1(BLM) helicase appears to be a central regulator of most of the recombination events that occur during S. cerevisiaemeiosis.[3] During normal meiosis Sgs1(BLM) is responsible for directing recombination towards the alternate formation of either early NCOs or Holliday junction joint molecules, the latter being subsequently resolved as COs.[3]
In the plant Arabidopsis thaliana, homologs of the Sgs1(BLM) helicase act as major barriers to meiotic CO formation.[4] These helicases are thought to displace the invading strand allowing its annealing with the other 3’overhang end of the DSB, leading to NCO recombinant formation by a process called synthesis dependent strand annealing (SDSA) (see Genetic recombination and Figure in this section). It is estimated that only about 4% of DSBs are repaired by CO recombination.[5] Sequela-Arnaud et al.[4] suggested that CO numbers are restricted because of the long-term costs of CO recombination, that is, the breaking up of favorable genetic combinations of alleles built up by past natural selection.
Interactions
Bloom syndrome protein has been shown to interact with:
↑Langland G, Kordich J, Creaney J, Goss KH, Lillard-Wetherell K, Bebenek K, Kunkel TA, Groden J (August 2001). "The Bloom's syndrome protein (BLM) interacts with MLH1 but is not required for DNA mismatch repair". J. Biol. Chem. 276 (32): 30031–5. doi:10.1074/jbc.M009664200. PMID11325959.
↑Wang XW, Tseng A, Ellis NA, Spillare EA, Linke SP, Robles AI, Seker H, Yang Q, Hu P, Beresten S, Bemmels NA, Garfield S, Harris CC (August 2001). "Functional interaction of p53 and BLM DNA helicase in apoptosis". J. Biol. Chem. 276 (35): 32948–55. doi:10.1074/jbc.M103298200. PMID11399766.
↑Garkavtsev IV, Kley N, Grigorian IA, Gudkov AV (December 2001). "The Bloom syndrome protein interacts and cooperates with p53 in regulation of transcription and cell growth control". Oncogene. 20 (57): 8276–80. doi:10.1038/sj.onc.1205120. PMID11781842.
↑Yang Q, Zhang R, Wang XW, Spillare EA, Linke SP, Subramanian D, Griffith JD, Li JL, Hickson ID, Shen JC, Loeb LA, Mazur SJ, Appella E, Brosh RM, Karmakar P, Bohr VA, Harris CC (August 2002). "The processing of Holliday junctions by BLM and WRN helicases is regulated by p53". J. Biol. Chem. 277 (35): 31980–7. doi:10.1074/jbc.M204111200. PMID12080066.
↑ 18.018.1Braybrooke JP, Li JL, Wu L, Caple F, Benson FE, Hickson ID (November 2003). "Functional interaction between the Bloom's syndrome helicase and the RAD51 paralog, RAD51L3 (RAD51D)". J. Biol. Chem. 278 (48): 48357–66. doi:10.1074/jbc.M308838200. PMID12975363.
↑Wu L, Davies SL, Levitt NC, Hickson ID (June 2001). "Potential role for the BLM helicase in recombinational repair via a conserved interaction with RAD51". J. Biol. Chem. 276 (22): 19375–81. doi:10.1074/jbc.M009471200. PMID11278509.
↑ 20.020.1Brosh RM, Li JL, Kenny MK, Karow JK, Cooper MP, Kureekattil RP, Hickson ID, Bohr VA (August 2000). "Replication protein A physically interacts with the Bloom's syndrome protein and stimulates its helicase activity". J. Biol. Chem. 275 (31): 23500–8. doi:10.1074/jbc.M001557200. PMID10825162.
↑Opresko PL, von Kobbe C, Laine JP, Harrigan J, Hickson ID, Bohr VA (October 2002). "Telomere-binding protein TRF2 binds to and stimulates the Werner and Bloom syndrome helicases". J. Biol. Chem. 277 (43): 41110–9. doi:10.1074/jbc.M205396200. PMID12181313.
↑Moens PB, Kolas NK, Tarsounas M, Marcon E, Cohen PE, Spyropoulos B (April 2002). "The time course and chromosomal localization of recombination-related proteins at meiosis in the mouse are compatible with models that can resolve the early DNA-DNA interactions without reciprocal recombination". J. Cell Sci. 115 (Pt 8): 1611–22. PMID11950880.
↑Wu L, Davies SL, North PS, Goulaouic H, Riou JF, Turley H, Gatter KC, Hickson ID (March 2000). "The Bloom's syndrome gene product interacts with topoisomerase III". J. Biol. Chem. 275 (13): 9636–44. doi:10.1074/jbc.275.13.9636. PMID10734115.
↑Hu P, Beresten SF, van Brabant AJ, Ye TZ, Pandolfi PP, Johnson FB, Guarente L, Ellis NA (June 2001). "Evidence for BLM and Topoisomerase IIIalpha interaction in genomic stability". Hum. Mol. Genet. 10 (12): 1287–98. doi:10.1093/hmg/10.12.1287. PMID11406610.
↑von Kobbe C, Karmakar P, Dawut L, Opresko P, Zeng X, Brosh RM, Hickson ID, Bohr VA (June 2002). "Colocalization, physical, and functional interaction between Werner and Bloom syndrome proteins". J. Biol. Chem. 277 (24): 22035–44. doi:10.1074/jbc.M200914200. PMID11919194.
Further reading
Woo LL, Onel K, Ellis NA (2007). "The broken genome: genetic and pharmacologic approaches to breaking DNA". Ann. Med. 39 (3): 208–18. doi:10.1080/08035250601167136. PMID17457718.
Ellis NA, Groden J, Ye TZ, Straughen J, Lennon DJ, Ciocci S, Proytcheva M, German J (1995). "The Bloom's syndrome gene product is homologous to RecQ helicases". Cell. 83 (4): 655–66. doi:10.1016/0092-8674(95)90105-1. PMID7585968.
Foucault F, Vaury C, Barakat A, Thibout D, Planchon P, Jaulin C, Praz F, Amor-Guéret M (1998). "Characterization of a new BLM mutation associated with a topoisomerase II alpha defect in a patient with Bloom's syndrome". Hum. Mol. Genet. 6 (9): 1427–34. doi:10.1093/hmg/6.9.1427. PMID9285778.
Kaneko H, Orii KO, Matsui E, Shimozawa N, Fukao T, Matsumoto T, Shimamoto A, Furuichi Y, Hayakawa S, Kasahara K, Kondo N (1997). "BLM (the causative gene of Bloom syndrome) protein translocation into the nucleus by a nuclear localization signal". Biochem. Biophys. Res. Commun. 240 (2): 348–53. doi:10.1006/bbrc.1997.7648. PMID9388480.
Wu L, Davies SL, North PS, Goulaouic H, Riou JF, Turley H, Gatter KC, Hickson ID (2000). "The Bloom's syndrome gene product interacts with topoisomerase III". J. Biol. Chem. 275 (13): 9636–44. doi:10.1074/jbc.275.13.9636. PMID10734115.
Brosh RM, Li JL, Kenny MK, Karow JK, Cooper MP, Kureekattil RP, Hickson ID, Bohr VA (2000). "Replication protein A physically interacts with the Bloom's syndrome protein and stimulates its helicase activity". J. Biol. Chem. 275 (31): 23500–8. doi:10.1074/jbc.M001557200. PMID10825162.
Dutertre S, Ababou M, Onclercq R, Delic J, Chatton B, Jaulin C, Amor-Guéret M (2000). "Cell cycle regulation of the endogenous wild type Bloom's syndrome DNA helicase". Oncogene. 19 (23): 2731–8. doi:10.1038/sj.onc.1203595. PMID10851073.
Barakat A, Ababou M, Onclercq R, Dutertre S, Chadli E, Hda N, Benslimane A, Amor-Guéret M (2000). "Identification of a novel BLM missense mutation (2706T>C) in a Moroccan patient with Bloom's syndrome". Hum. Mutat. 15 (6): 584–5. doi:10.1002/1098-1004(200006)15:6<584::AID-HUMU28>3.0.CO;2-I. PMID10862105.
Wu L, Davies SL, Levitt NC, Hickson ID (2001). "Potential role for the BLM helicase in recombinational repair via a conserved interaction with RAD51". J. Biol. Chem. 276 (22): 19375–81. doi:10.1074/jbc.M009471200. PMID11278509.
Langland G, Kordich J, Creaney J, Goss KH, Lillard-Wetherell K, Bebenek K, Kunkel TA, Groden J (2001). "The Bloom's syndrome protein (BLM) interacts with MLH1 but is not required for DNA mismatch repair". J. Biol. Chem. 276 (32): 30031–5. doi:10.1074/jbc.M009664200. PMID11325959.
Wang XW, Tseng A, Ellis NA, Spillare EA, Linke SP, Robles AI, Seker H, Yang Q, Hu P, Beresten S, Bemmels NA, Garfield S, Harris CC (2001). "Functional interaction of p53 and BLM DNA helicase in apoptosis". J. Biol. Chem. 276 (35): 32948–55. doi:10.1074/jbc.M103298200. PMID11399766.
Hu P, Beresten SF, van Brabant AJ, Ye TZ, Pandolfi PP, Johnson FB, Guarente L, Ellis NA (2001). "Evidence for BLM and Topoisomerase IIIalpha interaction in genomic stability". Hum. Mol. Genet. 10 (12): 1287–98. doi:10.1093/hmg/10.12.1287. PMID11406610.