Screen Of ER Interacted Proteins By Yeast Two-hybrid Assasy And Functional Analysis For The Protein Complex

Estrogen receptor (ER) is one of the members of the nuclear receptor superfamily, and contains two subtypes: a and p. ER plays an important role in the development of breast cancer. Recently ER is thought to act as a target of the therapy of breast cancer and good index of prognosis. Until now, the endocrine therapy of mammary carcinoma is acquired mainly by decreasing ER transcriptional activity. Therefore, it is of great significance to discover and characterize the proteins that modulate ER activity in developing the drugs of diseases related to estrogen.With ERα AF1 as bait, collagen I and FBLN1 was identified by yeast two-hybrid. Collagen I and FBLN1 are component of extracellular matrix (ECM), yeast two-hybrid assasy confirmed that collagen I and FBLN1 combined with ER directly. The collagen I and FBLN1 may participate in the ER signaling pathway to combine to regulate the cell procreation. Besides as mechanical barrier, ECM regulate tumor formation on molecular level through interaction between proteins.With ERβ AF2 as bait, HPIP and a new agnoprotein was identified by yeast two-hybrid. A yeast two-hybrid screen of a fetal liver-hematopoietic cDNA library using PBX1 as bait led to the discovery of this novel protein that interacts with PBX1 by Abramovich C in 2000 . PBX is a homeodomain protein that functions in complexes with other homeodomain-containing proteins to regulate gene expression during developmental and differentiation processes,including PBX1 , PBX2 , PBX3 and PBX4 . This protein that we have termed hematopoietic PBX-interacting protein (HPIP) is mainly localized in the cytosol and in small amounts in the nucleus. A yeast two-hybrid simulate internal environment completeiy .Tentatively confirmed that the bait protein combined with HPIP directly.As ER can bind to ERE (estrogen response element), ERE-containing luciferase reporter assay is used to detect the effects of HPIP...