Format

Send to

Choose Destination
Genes Cells. 2011 Jan;16(1):101-14. doi: 10.1111/j.1365-2443.2010.01467.x. Epub 2010 Dec 9.

Mutant Cockayne syndrome group B protein inhibits repair of DNA topoisomerase I-DNA covalent complex.

Author information

1
Human Cell Biology Group, Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan.

Abstract

Two UV-sensitive syndrome patients who have mild photosensitivity without detectable somatic abnormalities lack detectable Cockayne syndrome group B (CSB) protein because of a homozygous null mutation in the CSB gene. In contrast, mutant CSB proteins are produced in CS-B patients with the severe somatic abnormalities of Cockayne syndrome and photosensitivity. It is known that the piggyBac transposable element derived 3 is integrated within the CSB intron 5, and that CSB-piggyBac transposable element derived 3 fusion (CPFP) mRNA is produced by alternative splicing. We found that CPFP or truncated CSB protein derived from CPFP mRNA was stably produced in CS-B patients, and that wild-type CSB, CPFP, and truncated CSB protein interacted with DNA topoisomerase I. We also found that CPFP inhibited repair of a camptothecin-induced topoisomerase I-DNA covalent complex. The inhibition was suppressed by the presence of wild-type CSB, consistent with the autosomal recessive inheritance of Cockayne syndrome. These results suggested that reduced repair of a DNA topoisomerase I-DNA covalent complex because of truncated CSB proteins is involved in the pathogenesis of CS-B.

[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center