XBP-1 interacts with estrogen receptor alpha (ERalpha).
- Author:
Li-Hua DING
1
;
Qi-Nong YE
;
Jing-Hua YAN
;
Jian-Hua ZHU
;
Qiu-Jun LÜ
;
Zong-Hua WANG
;
Cui-Fen HUANG
Author Information
1. Beijing Institute of Biotechnology, Beijing 100850, China.
- Publication Type:Journal Article
- MeSH:
Breast Neoplasms;
genetics;
metabolism;
Cell Line, Tumor;
DNA-Binding Proteins;
genetics;
metabolism;
Estrogen Receptor alpha;
genetics;
metabolism;
Female;
Humans;
Protein Interaction Domains and Motifs;
physiology;
RNA, Messenger;
biosynthesis;
genetics;
Regulatory Factor X Transcription Factors;
Signal Transduction;
Transcription Factors;
genetics;
metabolism;
X-Box Binding Protein 1
- From:
Chinese Journal of Biotechnology
2004;20(3):332-336
- CountryChina
- Language:Chinese
-
Abstract:
Estrogen receptor alpha (ERalpha) has been a primary target of treatment as well as a prognostic indicator for breast cancer. The level of human X-box binding protein 1 (XBP-1) mRNA was related with that of ERalpha in breast tumors and was over-expressed in some breast tumors. These previous studies suggested that XBP-1 may interact with ERalpha. XBP-1 has two isoforms, XBP-1S and XBP-1U, as the result of unique splicing. GST pull-down assay showed that both XBP-1S and XBP-1U bound to ERalpha in vitro. The binding of XBP-1S to ERalpha was stronger than that of XBP-1U to ERalpha. Co-immunoprecipitation revealed that the binding was in a ligand-independent manner. XBP-1S and XBP-1U interacted with the region of ERalpha that contains a DNA-binding domain. The ERalpha-interacting regions on XBP-1S and XBP-1U have been mapped to two regions, the N-terminal basic region leucine zipper domain (bzip) and the C-terminal activation domain. These findings suggest that XBP-1S and XBP-1U may participate in ERalpha signaling pathway through the mediation of ERalpha.
