The BioGRID | PUBLICATION VIEW

	Biochem. Biophys. Res. Commun. Dec (2004); 325(2):568-73
COBRA1 inhibits AP-1 transcriptional activity in transfected cells.
Zhong H, Zhu J, Zhang H, Ding L, Sun Y, Huang C, Ye Q
Beijing Institute of Biotechnology, 27 Tai-Ping Lu Rd, Beijing 100850, PR China.
Abstract: Mutations in the breast cancer susceptibility gene (BRCA1) account for a significant proportion of hereditary breast and ovarian cancers. Cofactor of BRCA1 (COBRA1) was isolated as a BRCA1-interacting protein and exhibited a similar chromatin reorganizing activity to that of BRCA1. However, the biological role of COBRA1 remains largely unexplored. Here, we report that ectopic expression of COBRA1 inhibited activator protein 1 (AP-1) transcriptional activity in transfected cells in a dose-dependent manner, whereas reduction of endogenous COBRA1 with a small interfering RNA significantly enhanced AP-1-mediated transcriptional activation. COBRA1 physically interacted with the AP-1 family members, c-Jun and c-Fos, and the middle region of COBRA1 bound to c-Fos. Lack of c-Fos binding site in the COBRA1 completely abolished the COBRA1 inhibition of AP-1 trans-activation. These findings suggest that COBRA1 may directly modulate AP-1 pathway and, therefore, may play important roles in cell proliferation, differentiation, apoptosis, and oncogenesis.
[PUBMED: 15530430]