Identification of phosphorylation sites in the mouse oestrogen receptor.
Phosphorylation sites in the mouse oestrogen receptor, expressed in COS-1 cells in the presence of 17 beta-oestradiol, have been mapped by solid phase microsequencing. The receptor was first radio-labelled with [32P]orthophosphate and a number of 3H- or 14C-labelled amino acids, immunopurified and then tryptic peptides were separated by thin layer chromatography or high performance liquid chromatography. Amino acid sequence analysis indicated that Ser-122, Ser-156, Ser-158 and Ser-298 were phosphorylated. The substitution of Ser-122 and Ser-298 with alanine had a negligible effect on the transcriptional activity of the receptor in transfected cells. However, a reduction of transcriptional activity was observed when Ser-122 was mutated in the context of mutations in a putative amphipathic alpha-helix involved in AF-2 activity. Thus a region of AF-1 that encompasses Ser-122 appears to interact with AF-2 in the full-length receptor.
Molecular Endocrinology, Laboratory Imperial Cancer Research Fund, London, U.K.
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H
Lahooti
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White
S A
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Hoare
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Rahman
D J
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Pappin
M G
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Parker
D016475:3T3 Cells; D000409:Alanine; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D004958:Estradiol / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D010446:Peptide Fragments / Q000737:chemistry; D010766:Phosphorylation; D010768:Phosphoserine; D011960:Receptors, Estrogen / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D017421:Sequence Analysis / Q000379:methods; D014158:Transcription, Genetic; D014162:Transfection
D010446:Peptide Fragments; D011960:Receptors, Estrogen; D010768:Phosphoserine; D004958:Estradiol; D000409:Alanine