Hsp56: A novel heat shock protein associated with untransformed steroid receptor complexes

Journal Article · Tue Dec 25 00:00:00 EST 1990 · Journal of Biological Chemistry; (USA)

OSTI ID:6152057

Sanchez, E R ^[1]

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1. Medical College of Ohio, Toledo (USA)

The recently-described p59 protein has been shown to be associated with untransformed steroid receptors present in rabbit uterus and rat liver cytosols while a smaller version of this protein (p56) interacts with glucocorticoid receptors in human IM-9 cell cytosols. In addition to interacting with glucocorticoid receptors, the p56 protein of IM-9 cell cytosol is also found as part of a large heteromeric complex that contains both the 70-kDa and 90-kDa heat shock proteins (hsp70 and hsp90, respectively). Given this association of p56 with the two major stress proteins, I have speculated that p56 may itself be a heat shock protein. In this paper, the effect of heat stress on the rate of synthesis of p56 is determined. Intact IM-9 cells were exposed to 37 or 43 degrees C for 4 h, followed by pulse-labeling with (35S)methionine. Analysis of whole cytosolic extracts by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography reveal an increased rate of radiolabeling for hsp70, hsp90, hsp100, ad hsp110, but no heat-inducible protein of smaller relative molecular mass is detected. However, immune-purification of p56 from normal and heat-stressed cytosols with the EC1 monoclonal antibody results in the presence of a 56-kDa protein that exhibits an increased rate of synthesis in response to heat stress. The results of two-dimensional gel Western blots employing the EC1 antibody demonstrate that this heat-inducible protein is indeed the EC1-reactive p56 protein and that the induction effect is not due to unequal yields of p56 during immune-purification.

• OSTI ID: 6152057
• Journal Information: Journal of Biological Chemistry; (USA), Vol. 265:36; ISSN 0021-9258
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
GLUCOCORTICOIDS
RECEPTORS
HEAT
BIOLOGICAL EFFECTS
PROTEINS
BIOSYNTHESIS
AUTORADIOGRAPHY
COMPLEXES
ELECTROPHORESIS
LIVER
METHIONINE
MONOCLONAL ANTIBODIES
RABBITS
RATS
SULFUR 35
UTERUS
ADRENAL HORMONES
AMINO ACIDS
ANIMALS
ANTIBODIES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CARBOXYLIC ACIDS
CORTICOSTEROIDS
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
DRUGS
ENERGY
EVEN-ODD NUCLEI
FEMALE GENITALS
GLANDS
HYDROXY COMPOUNDS
ISOTOPES
KETONES
LIGHT NUCLEI
LIPOTROPIC FACTORS
MAMMALS
MEMBRANE PROTEINS
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANS
PREGNANES
RADIOISOTOPES
RODENTS
STEROIDS
SULFUR ISOTOPES
SYNTHESIS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques