[Isolation and characterization of a BRCA1-interacting protein].

BRCA1 (breast cancer susceptibility gene-1) plays important roles in DNA damage repair, cell checkpoint regulation, gene transcription, chromosome stability, and apoptosis. At the C-terminus of BRCA1 is the activation domain with a number of acidic amino acid residues that includes two tandem repeats of BRCT(BRCT1 and BRCT2). In this study, to identify proteins that interact with the BRCT2 domain of BRCA1, the standard yeast two-hybird screen was performed.

[XBP-1 enhances the transcriptional activity of estrogen receptor alpha].

The estrogen receptor (ERalpha) is a member of a large superfamily of nuclear receptors that regulates the transcription of estrogen-responsive genes. Several recent studies have demonstrated that human X-box binding protein 1 (XBP-1) mRNA expression is associated with ERalpha status in breast tumors. More recently, two forms of XBP-1 were identified due to their unique splicing.

[Construction of ERbeta expression vector and its function in different cancer cells].

Objective: To construct an ERbeta expression vector and study its expression and function in different cancer cells.

Methods: Standard PCR was used to amplify the full-length coding sequence of ERbeta. The amplified ERbeta gene was cloned into the eukaryotic expression vector pCDNA3, generating pCDNA3-ERbeta.

[Mapping of BRCT1 domain of BRCA1 with chromatin unfolding activity].

Breast cancer susceptibility gene 1(BRCA1) plays an important role in breast cancer development and progression. BRCA1 encodes a 1863-amino acid protein with two BRCA1 C-terminal (BRCT) domains at its C-terminus, BRCT1 and BRCT2. Many cancer-predisposing mutations are located in the BRCT domains, which have been shown to induce chromatin unfolding by use of an approach that allows visualization of large-scale chromatin structure through lac repressor/lac operator recognition.

[Studies of mutations in BRCA1 transactivation domain by visualization of chromatin structure].

Mutations in breast cancer susceptibility gene 1(BRCA1) account for approximately 40%-50% of familial breast cancer cases and for more than 80% of inherited breast and ovarian cancer cases. Many cancer-predisposing mutations are located in the C-terminal region that functions as a transcriptional activation domain, but most of the mutations in the transactivation domain identified to date cannot be readily distinguished as either disease-associated mutations or benign polymorphisms. Because chromatin structure regulation is an early event in gene transcription control, the chromatin unfolding activities of different transactivation domain variants were compared with that of the wild-type transactivation domain by use of an approach that allows visualization of large-scale chromatin structure through lac repressor/lac operator recognition.