title: Specific association of estrogen receptor beta with the cell cycle spindle assembly checkpoint protein, MAD2.
abstract: Estrogen receptors (ERs) are ligand-activated transcription factors that regulate gene expression and cell growth. Two ERs now have been identified: ERalpha and the more recently discovered ERbeta. The physiological function of ERbeta remains unclear, but evidence from vascular injury studies and from ERbeta knockout mice suggests that ERbeta may be involved in the regulation of cellular proliferation. Here we show a direct and specific interaction between ERbeta and the cell cycle mitotic spindle assembly checkpoint protein, MAD2 (mitosis arrest-deficient 2). The ERbeta-MAD2 interaction was identified by screening of a yeast two-hybrid system vascular endothelial cell library with ERbeta and confirmed with glutathione S-transferase-fusion protein interaction studies. In contrast, ERalpha did not interact with MAD2 in either the two-hybrid system or in the protein-protein interaction experiments. Amino acids 173-208 in the hinge region of ERbeta were sufficient to mediate the interaction with MAD2 in the two-hybrid system and in glutathione S-transferase-fusion protein studies. These data identify a link between ERbeta and MAD2 of potential importance to regulation of the cell cycle and support a function of ERbeta distinct from the established role of ERs as transcription factors.
authors.affiliation: Molecular Cardiology Research Institute, Cardiology Division, Department of Medicine, Tufts University School of Medicine and New England Medical Center, Boston, MA 02111, USA.
authors.forename: G
authors.initials: G
authors.lastname: Poelzl
authors.forename: Y
authors.initials: Y
authors.lastname: Kasai
authors.forename: N
authors.initials: N
authors.lastname: Mochizuki
authors.forename: P W
authors.initials: PW
authors.lastname: Shaul
authors.forename: M
authors.initials: M
authors.lastname: Brown
authors.forename: M E
authors.initials: ME
authors.lastname: Mendelsohn
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D002352:Carrier Proteins; D002453:Cell Cycle; D018797:Cell Cycle Proteins; D004730:Endothelium, Vascular / Q000378:metabolism; D047629:Estrogen Receptor beta; D005656:Fungal Proteins / Q000378:metabolism*; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D011485:Protein Binding; D011651:Pulmonary Artery / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012756:Sheep; D020798:Two-Hybrid System Techniques
chemical_list: D002135:Calcium-Binding Proteins; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D047629:Estrogen Receptor beta; D005656:Fungal Proteins; D009687:Nuclear Proteins; D011960:Receptors, Estrogen; D011993:Recombinant Fusion Proteins; D005982:Glutathione Transferase