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Werner syndrome (WS) is the hallmark premature aging syndrome in which the patients appear much older than their actual chronological age. The disorder is associated with significantly increased genome instability and with transcriptional deficiencies. There has been some uncertainty about whether WS cells are defective in DNA repair. We thus examined(More)
Individuals affected by the autosomal recessive disorder Werner's syndrome (WS) develop many of the symptoms characteristic of premature ageing. Primary fibroblasts cultured from WS patients exhibit karyotypic abnormalities and a reduced replicative life span. The WRN gene encodes a 3'-5' DNA helicase, and is a member of the RecQ family, which also includes(More)
BLM and WRN, the products of the Bloom's and Werner's syndrome genes, are members of the RecQ family of DNA helicases. Although both have been shown previously to unwind simple, partial duplex DNA substrates with 3'-->5' polarity, little is known about the structural features of DNA that determine the substrate specificities of these enzymes. We have(More)
The RecQ helicase family comprises a conserved group of proteins implicated in several aspects of DNA metabolism. Three of the family members are defective in heritable diseases characterized by abnormal growth, premature aging, and predisposition to malignancies. These include the WRN and BLM gene products that are defective in Werner and Bloom syndromes,(More)
Werner Syndrome is a premature aging disorder characterized by genomic instability, elevated recombination, and replication defects. It has been hypothesized that defective processing of certain replication fork structures by WRN may contribute to genomic instability. Fluorescence resonance energy transfer (FRET) analyses show that WRN and Flap(More)
FANCJ mutations are associated with breast cancer and genetically linked to the bone marrow disease Fanconi anemia (FA). The genomic instability of FA-J mutant cells suggests that FANCJ helicase functions in the replicational stress response. A putative helicase with sequence similarity to FANCJ in Caenorhabditis elegans (DOG-1) and mouse (RTEL) is required(More)
Bloom's syndrome (BS) is a rare autosomal recessive genetic disorder associated with genomic instability and an elevated risk of cancer. Cellular features of BS include an accumulation of abnormal replication intermediates and increased sister chromatid exchange. Although it has been suggested that the underlying defect responsible for hyper-recombination(More)
Bloom's syndrome is a rare autosomal recessive disorder characterized by genomic instability and predisposition to cancer. BLM, the gene defective in Bloom's syndrome, encodes a 159-kDa protein possessing DNA-stimulated ATPase and ATP-dependent DNA helicase activities. We have examined mechanistic aspects of the catalytic functions of purified recombinant(More)
The human premature aging disorder Werner syndrome (WS) is associated with a large number of symptoms displayed in normal aging. The WRN gene product, a DNA helicase, has been previously shown to unwind short DNA duplexes (</=53 base pairs) in a reaction stimulated by single-stranded DNA-binding proteins. We have studied the helicase activity of purified(More)
FANCJ also called BACH1/BRIP1 was first linked to hereditary breast cancer through its direct interaction with BRCA1. FANCJ was also recently identified as a Fanconi anemia (FA) gene product, establishing FANCJ as an essential tumor suppressor. Similar to other FA cells, FANCJ-null (FA-J) cells accumulate 4N DNA content in response to DNA interstrand(More)