Adrenocortical nuclear progesterone-binding protein: Identification by photoaffinity labeling and evidence for deoxyribonucleic acid binding and stimulation by adrenocorticotropin
- National Institute of Child Health and Human Development, Bethesda, MD (USA)
Nuclei of the guinea pig adrenal cortex contain a protein that specifically binds progesterone and that, biochemically, is clearly distinct from the classical progesterone receptor. The adrenocortical nuclear progesterone-binding protein has now been purified more than 2000-fold by steroid-affinity chromatography with a 75% yield. The purified protein preparation demonstrated three major bands on sodium dodecyl sulfate-polyacrylamide gel of 79K, 74K, and 50K. To determine which of the three might represent the progesterone-binding protein, steroid photoaffinity labeling was performed which resulted in the specific and exclusive labeling of a 50K band. Thus, the adrenocortical nuclear progesterone-binding protein appears to be distinct from the classical progesterone receptor not only biochemically, but also on the basis of molecular size. To test whether the adrenocortical nuclear progesterone-binding protein can be hormonally stimulated, guinea pigs were treated with ACTH. The chronic administration of ACTH caused a 4- to 6-fold increase in the specific progesterone binding capacity without a change in the binding affinity. There appeared to be no significant difference in nuclear progesterone binding between the zona fasciculata and zona reticularis. This finding suggests a mediating role for the progesterone-binding protein in ACTH action. In addition, the nuclear progesterone-binding protein bound to nonspecific DNA sequences, further suggesting a possible transcriptional regulatory role.
- OSTI ID:
- 6215424
- Journal Information:
- Endocrinology; (USA), Vol. 128:1; ISSN 0013-7227
- Country of Publication:
- United States
- Language:
- English
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DNA
BIOCHEMICAL REACTION KINETICS
PITUITARY HORMONES
PROGESTERONE
RECEPTORS
PROTEINS
LABELLING
ADRENAL GLANDS
AFFINITY
CELL NUCLEI
GUINEA PIGS
MOLECULAR WEIGHT
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ANIMALS
BODY
CELL CONSTITUENTS
ENDOCRINE GLANDS
GLANDS
HORMONES
HYDROGEN COMPOUNDS
ISOTOPE APPLICATIONS
KETONES
KINETICS
MAMMALS
MEMBRANE PROTEINS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PEPTIDE HORMONES
PREGNANES
REACTION KINETICS
RODENTS
STEROID HORMONES
STEROIDS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques