title: A 12(S)-hydroxyeicosatetraenoic acid receptor interacts with steroid receptor coactivator-1.
abstract: Lewis lung carcinoma cells contain specific high-affinity binding sites for the eicosanoid 12(S)-hydroxy-5,8,10,14-eicosatetraenoic acid [12(S)-HETE]. These binding sites have a cytosolic/nuclear localization and contain the heat shock proteins hsp70 and hsp90 as components of a high molecular weight cytosolic binding complex. The ligand binding subunit of this complex is a protein with an apparent molecular mass of approximately 50 kDa as judged by gel permeation chromatography. In this report, we present data showing that the 50-kDa 12(S)-HETE binding protein interacts as a homodimer with steroid receptor coactivator-1 (SRC-1) in the presence of 12(S)-HETE. Two putative interaction domains were mapped. One of these (amino acids 701-781) was within the nuclear receptor interaction domain in SRC-1 required for binding of various steroid and thyroid hormone receptors. It contains the most C-terminal of the three copies of LXXLL motif present in the nuclear receptor interaction domain. The second interaction domain was present in the N-terminal part of SRC-1 (amino acids 1-221). This region has two LXXLL motifs, one does not bind and the other binds only weakly to steroid and thyroid hormone receptors. Glutathione S-transferase (GST) pulldown experiments and far Western analyses demonstrated that the N-terminal region of SRC-1 (amino acids 1-212) alone does not bind the 50-kDa 12(S)-HETE binding protein, whereas GST/DeltaSRC-1(1-1138) ligand-dependently pulled down a protein of approximately 50 kDa in size. Our results suggest that the 50-kDa 12(S)-HETE binding protein is a receptor that may signal through interaction with a nuclear receptor coactivator protein.
authors.affiliation: Department of Biomedicine and Surgery, Division of Cell Biology, Linköping University, S-581 85 Linköping, Sweden.
authors.forename: Y
authors.initials: Y
authors.lastname: Kurahashi
authors.forename: H
authors.initials: H
authors.lastname: Herbertsson
authors.forename: M
authors.initials: M
authors.lastname: Söderström
authors.forename: M G
authors.initials: MG
authors.lastname: Rosenfeld
authors.forename: S
authors.initials: S
authors.lastname: Hammarström
mesh_terms: D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid / Q000378:metabolism*; D000818:Animals; D001665:Binding Sites; D015153:Blotting, Western; D018827:Carcinoma, Lewis Lung / Q000378:metabolism / Q000473:pathology; D011232:Chemical Precipitation; D002850:Chromatography, Gel; D005982:Glutathione Transferase / Q000235:genetics; D051548:Histone Acetyltransferases; D006801:Humans; D007525:Isoelectric Focusing; D051379:Mice; D009363:Neoplasm Proteins / Q000378:metabolism; D056920:Nuclear Receptor Coactivator 1; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D018055:Receptors, Eicosanoid / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000032:analysis; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
chemical_list: C066652:12-hydroxyeicosatetraenoic acid receptor; D009363:Neoplasm Proteins; D018055:Receptors, Eicosanoid; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; D051548:Histone Acetyltransferases; C538859:NCOA1 protein, human; C538861:Ncoa1 protein, mouse; D056920:Nuclear Receptor Coactivator 1; D005982:Glutathione Transferase