Register for One of 3 BLM helicase complexes, BRAFT, contains 5 Fanconi anemia proteins
Bloom SyndromeAugust 6, 2003
One of the three Bloom syndrome BLM helicase complexes, BRAFT, contains 5 of the Fanconi anemia proteins.
"Bloom syndrome (BS) is a genetic disorder associated with dwarfism, immunodeficiency, reduced fertility, and an elevated risk of cancer. To investigate the mechanism of this disease, we isolated from human HeLa extracts three complexes containing the helicase defective in BS, BLM. Interestingly, one of the complexes, termed BRAFT, also contains five of the Fanconi anemia (FA) complementation group proteins (FA proteins)," researchers in the United States report.
"FA resembles BS in genomic instability and cancer predisposition, but most of its gene products have no known biochemical activity, and the molecular pathogenesis of the disease is poorly understood. BRAFT displays a DNA-unwinding activity, which requires the presence of BLM because complexes isolated from BLM-deficient cells lack such an activity. The complex also contains topoisomerase IIIalpha and replication protein A, proteins that are known to interact with BLM and could facilitate unwinding of DNA. We show that BLM complexes isolated from an FA cell line have a lower molecular mass," wrote A.R. Meetei and colleagues.
The researchers concluded: "Our study provides the first biochemical characterization of a multiprotein FA complex and suggests a connection between the BLM and FA pathways of genomic maintenance. The findings that FA proteins are part of a DNA-unwinding complex imply that FA proteins may participate in DNA repair."
Meetei and coauthors published their study in Molecular and Cellular Biology (A multiprotein nuclear complex connects Fanconi anemia and Bloom syndrome. Mol Cell Biol, 2003;23(10):3417-3426).
For additional information, contact W.D. Wang, NIA, Genetics Laboratory, Mass Spectrometry Unit, NIH, 333 Cassell Dr., TRIAD Center Rm 3000, Baltimore, MD 21224, USA.
Publisher contact information for the journal Molecular and Cellular Biology is: American Society Microbiology, 1752 N St. NW, Washington, DC 20036-2904, USA.
The information in this article comes under the major subject areas of Genomics and Genetics, Proteomics, Hematology, Immunology and Oncology. This article was prepared by Health & Medicine Week editors from staff and other reports.
©Copyright 2003, via NewsRx.com & NewsRx.net
