Identification of DBC1 as a transcriptional repressor for BRCA1

H. Hiraike,O. Wada-Hiraike,S. Nakagawa,S. Koyama,Y. Miyamoto,K. Sone,M. Tanikawa,T. Tsuruga,K. Nagasaka,Yu Matsumoto,K. Oda,Kumi Shoji,H. Fukuhara,S. Saji,K. Nakagawa,Shigeaki Kato,T. Yano,Yuji Taketani

Published 2010 in British Journal of Cancer

ABSTRACT

Background:DBC1/KIAA1967 (deleted in breast cancer 1) is a putative tumour-suppressor gene cloned from a heterozygously deleted region in breast cancer specimens. Caspase-dependent processing of DBC1 promotes apoptosis, and depletion of endogenous DBC1 negatively regulates p53-dependent apoptosis through its specific inhibition of SIRT1. Hereditary breast and ovarian cancer susceptibility gene product BRCA1, by binding to the promoter region of SIRT1, is a positive regulator of SIRT1 expression.Methods:A physical interaction between DBC1 and BRCA1 was investigated both in vivo and in vitro. To determine the pathophysiological significance of DBC1, its role as a transcriptional factor was studied.Results:We found a physical interaction between the amino terminus of DBC1 and the carboxyl terminus of BRCA1, also known as the BRCT domain. Endogenous DBC1 and BRCA1 form a complex in the nucleus of intact cells, which is exported to the cytoplasm during ultraviolet-induced apoptosis. We also showed that the expression of DBC1 represses the transcriptional activation function of BRCT by a transient expression assay. The expression of DBC1 also inhibits the transactivation of the SIRT1 promoter mediated by full-length BRCA1.Conclusion:These results revealed that DBC1 may modulate the cellular functions of BRCA1 and have important implications in the understanding of carcinogenesis in breast tissue.

PUBLICATION RECORD

CITATION MAP

EXTRACTION MAP

CLAIMS

  • No claims are published for this paper.

CONCEPTS

  • No concepts are published for this paper.

REFERENCES

Showing 1-31 of 31 references · Page 1 of 1

CITED BY

Showing 1-83 of 83 citing papers · Page 1 of 1