Functions of RecQ family helicases: possible involvement of Bloom's and Werner's syndrome gene products in guarding genome integrity during DNA replication.
Escherichia coli RecQ helicase is a component of the RecF pathway of recombination whose components are required to reassemble a replisome complex at the site of the replication fork after the removal of a lesion. There are at least five RecQ homologues in human cells, including BLM and WRN. The genes encoding BLM and WRN are mutated in the cancer-prone disorder Bloom's syndrome (BS) and the plogeroid disorder Werner's syndrome (WS), respectively. These syndromes are characterized by a high degree of genomic instability, including chromosomal breaks, multiple large deletions, and translocations, and cells derived from BS and WS patients show defects in DNA replication. Recently, it has become clear that a Holliday junction-like structure is formed at stalled replication forks to result in the formation of double-stranded breaks, and recombination plays an important role in the repair of stalled or broken replication forks, leading to the reinitiation of replication. Defects in the processing of stalled replication forks could lead to aberrant recombination events resulting in genetic instability. Recent studies on BLM, WRN, and the RecQ homologue of Saccharomyces cerevisiae, Sgs1, indicate that these RecQ homologues interact with proteins involved in DNA replication, and function in a pathway from the DNA replication check point to homologous recombination.
Molecular Cell Biology Laboratory, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan. enomoto@mail.pharm.tohoku.ac.jp
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D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry; D001816:Bloom Syndrome / Q000201:enzymology / Q000235:genetics; D004265:DNA Helicases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D004261:DNA Replication / Q000235:genetics*; D005090:Exodeoxyribonucleases; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016678:Genome; D006801:Humans; D011485:Protein Binding; D053484:RecQ Helicases; D029701:Saccharomyces cerevisiae Proteins; D012854:Sister Chromatid Exchange / Q000235:genetics; D014898:Werner Syndrome / Q000201:enzymology / Q000235:genetics; D000071657:Werner Syndrome Helicase
D001426:Bacterial Proteins; D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins; D005090:Exodeoxyribonucleases; D000251:Adenosine Triphosphatases; C097151:Bloom syndrome protein; C506725:RECQL protein, human; C506724:RecQ protein, E coli; C090472:SGS1 protein, S cerevisiae; D004265:DNA Helicases; D053484:RecQ Helicases; C098785:WRN protein, human; D000071657:Werner Syndrome Helicase