Isoform composition and stoichiometry of the approx. 90-kDa heat shock protein associated with glucocorticoid receptors
The authors observed that the approx. 90-kDa non-steroid-binding component of nonactivated glucocorticoid receptors purified from WEHI-7 mouse thymoma cells (which has been identified as the approx. 90-kDa heat shock protein) consistently migrates as a doublet during polyacrylamide gel electrophoresis under denaturing and reducing conditions. It has recently been reported that murine Meth A cells contain a tumor-specific transplantation antigen (TSTA) which is related or identical to the approx. 90-kDa heat shock protein. The observation that TSTA and the approx. 90-kDa heat shock protein isolated from these cells exists as two isoforms of similar molecular mass and charge has suggested that the doublet observed is also due to the existence of two isoforms. They have therefore conducted this study to determine whether TSTA and the approx. 90-kDa component of glucocorticoid receptors are indeed related, to establish whether the receptor preferentially binds one isoform of the approx. 90-kDa heat shock protein, and to investigate the stoichiometry of the nonactivated receptor complex. They used the BuGr1 and AC88 monoclonal antibodies to purify, respectively, receptor-associated and free approx. 90-kDa heat shock protein from WEHI-7 cells grown for 48 h with (/sup 35/S)methionine to metabolically label proteins to steady state. The long-term metabolic labeling approach has also enabled them to directly determine that the purified non-activated glucocorticoid receptor contains a single steroid-binding protein and two approx. 90-kDa non-steroid-binding subunits. The consistency with which a approx. 1:2 stoichiometric ratio of steroid binding to approx. 90-kDa protein is observed supports the view that the approx. 90-kDa heat shock protein is a true component of nonactivated glucocorticoid-receptor complexes.
- Research Organization:
- Dartmouth Medical School, Hanover, NH (USA)
- OSTI ID:
- 6838345
- Journal Information:
- J. Biol. Chem.; (United States), Vol. 263:14
- Country of Publication:
- United States
- Language:
- English
Similar Records
Phosphorylated sites within the functional domains of the @ 100-kDa steroid-binding subunit of glucocorticoid receptors
Identification of cysteine-644 as the covalent site of attachment of dexamethasone 21-mesylate to murine glucocorticoid receptors in WEHI-7 cells
Related Subjects
PROTEINS
MOLECULAR STRUCTURE
STOICHIOMETRY
RECEPTORS
SULFUR 35
TRACER TECHNIQUES
ELECTROPHORESIS
GLUCOCORTICOIDS
METHIONINE
MICE
MONOCLONAL ANTIBODIES
TUMOR CELLS
ADRENAL HORMONES
AMINO ACIDS
ANIMAL CELLS
ANIMALS
ANTIBODIES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBOXYLIC ACIDS
CORTICOSTEROIDS
DAYS LIVING RADIOISOTOPES
DRUGS
EVEN-ODD NUCLEI
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
ISOTOPES
KETONES
LIGHT NUCLEI
LIPOTROPIC FACTORS
MAMMALS
MEMBRANE PROTEINS
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PREGNANES
RADIOISOTOPES
RODENTS
STEROIDS
SULFUR ISOTOPES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques