title: Analysis of estrogen receptor alpha signaling complex at the plasma membrane.
abstract: There is accumulating evidence that the estrogen receptor (ER) can transduce specific signals at the plasma membrane. We tried to clarify the biological function of ER as a signaling molecule by identifying proteins that interact with the membrane-localized ER. The activation function 1 and 2 (AF-1 and AF-2) domains of ERalpha with or without the membrane-targeting sequence were stably expressed in the breast cancer cell line, MCF-7. The level of tyrosine phosphorylation of AF-2 was significantly elevated by the membrane localization. By mass-spectrometry analysis, alpha- and beta-tubulins and heat shock protein 70 were identified as the AF-1-associated proteins. Of these, tubulins are associated only with membrane-targeted AF-1.
authors.affiliation: Growth Factor Division, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan.
authors.forename: Kotaro
authors.initials: K
authors.lastname: Azuma
authors.forename: Kuniko
authors.initials: K
authors.lastname: Horie
authors.forename: Satoshi
authors.initials: S
authors.lastname: Inoue
authors.forename: Yasuyoshi
authors.initials: Y
authors.lastname: Ouchi
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Sakai
mesh_terms: D000911:Antibodies, Monoclonal / Q000378:metabolism; D001943:Breast Neoplasms / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism*; D047628:Estrogen Receptor alpha / Q000032:analysis* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005260:Female; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D013058:Mass Spectrometry; D010766:Phosphorylation; D017434:Protein Structure, Tertiary; D015398:Signal Transduction; D015533:Transcriptional Activation; D014404:Tubulin / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D047628:Estrogen Receptor alpha; D018840:HSP70 Heat-Shock Proteins; D014404:Tubulin; D014443:Tyrosine