HnRNP A3 binds to and protects mammalian telomeric repeats in vitro
- Biochemistry Division, National Cancer Center Research Institute, Tsukiji 5, Chuo-ku, Tokyo 104-0045 (Japan)
- Division of Molecular Biotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, Ariake, Koto-ku, Tokyo 135-8550 (Japan)
The biological function of hnRNP family proteins is widely diverse and involved in pre-mRNA processing, transcriptional regulation, recombination, and telomere maintenance. In the course of our study on the elucidation of biological functions of minisatellite DNA, we isolated several nuclear proteins that bind to the mouse minisatellite Pc-1, which consists of a tandem array of d(GGCAG) repeats, from NIH3T3 cells. One of the minisatellite binding proteins, MNBP-A, which binds to a single-stranded G-rich strand of the Pc-1 repeat, was proven identical to the hnRNP A3. Recombinant hnRNP A3 was demonstrated to bind to the single-stranded telomeric d(TTAGGG) repeat with much higher affinity than the d(GGCAG) repeat. Binding of hnRNP A3 to the single-stranded telomeric repeat protected the repeat from nuclease attack, and inhibited both telomerase reaction and DNA synthesis in vitro. These results suggest a possible biological role of hnRNP A3 in the stable maintenance of telomere repeats.
- OSTI ID:
- 20991417
- Journal Information:
- Biochemical and Biophysical Research Communications, Journal Name: Biochemical and Biophysical Research Communications Journal Issue: 2 Vol. 358; ISSN 0006-291X; ISSN BBRCA9
- Country of Publication:
- United States
- Language:
- English
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