Uterine estrogen receptor in vivo: Phosphorylation of nuclear specific forms on serine residues

Journal Article · Fri Feb 01 04:00:00 EST 1991 · Molecular Endocrinology; (United States)

DOI:https://doi.org/10.1210/mend-5-2-235· OSTI ID:5398715

Washburn, T; Hocutt, A; Brautigan, D L; Korach, K S ^[1]

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1. Receptor Biology Section, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC (USA)

We have characterized further the heterogeneous nuclear-specific doublet forms of the mouse uterine estrogen receptor (ER). Estrogen treatment produced the multiple nuclear ER forms of 65 and 66.5 kDa, which were isolated and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Soluble ER preparations exhibited only a single 65-kDa form. Isolation of the individual nuclear ER forms and reanalysis demonstrated that formation of the multiple bands was not due to artifacts of nuclear sample preparation or the presence of contaminating proteins. Analysis of individual uterine cell types (epithelial and stromal/myometrium) indicated that both ER forms were present in both cell fractions. Fractionation of nuclear components with low salt showed that both ER forms were found in the salt-resistant fraction. Extraction of nuclei with high salt (0.6 M KCl) solubilized both ER forms. Phosphorylation was studied as a protein modification to account for the multiple forms. Incorporation of 32P into uterine protein both in vivo and in intact tissue incubation indicated 32P labeling of uterine nuclear ER after hormone treatment. Both nuclear ER forms are labeled, although the 66.5-kDa form appears to be more heavily labeled. Phosphoamino acid analysis of the immunopurified 32P-labeled ER from intact uterine tissue indicated phosphoserine as the only phospholabeled residue. These data suggest that phosphorylation is associated with the physiological functioning of the ER in response to hormone and produces the heterogeneous ER forms in the nucleus.

• OSTI ID: 5398715
• Journal Information: Molecular Endocrinology; (United States), Journal Name: Molecular Endocrinology; (United States) Vol. 5:2; ISSN 0888-8809; ISSN MOENE
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CELL NUCLEI
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
DAYS LIVING RADIOISOTOPES
ELECTROPHORESIS
ESTRADIOL
ESTRANES
ESTROGENS
FEMALE GENITALS
HORMONES
HYDROXY ACIDS
HYDROXY COMPOUNDS
IN VIVO
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
MAMMALS
MEMBRANE PROTEINS
MICE
MOLECULAR WEIGHT
NUCLEI
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PHOSPHORYLATION
PROTEINS
RADIOISOTOPES
RECEPTORS
RODENTS
SERINE
STEROID HORMONES
STEROIDS
TRACER TECHNIQUES
UTERUS
VERTEBRATES