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Updated: Aug 7, 2026
11:07
Biochemical Reconstitution of Steroid Receptor•Hsp90 Protein Complexes and Reactivation of Ligand Binding
Published on: September 21, 2011
Two point mutations in the hormone-binding domain of the mouse glucocorticoid receptor that dramatically reduce its
S Byravan1, J Milhon, S K Rabindran
1Department of Pathology, University of Southern California Health Sciences Center, Los Angeles 90033.
Molecular Endocrinology (Baltimore, Md.)
|June 1, 1991
Summary
Mutant glucocorticoid receptors (GR) in lymphoma cells show altered function. One mutation requires 100x more hormone for response, while another causes instability and non-functionality.
Area of Science:
- Molecular Biology
- Cell Biology
- Endocrinology
Background:
- Mouse lymphoma cell line W7M320b exhibits reduced sensitivity to glucocorticoids.
- Understanding glucocorticoid receptor (GR) function is crucial for hormone response mechanisms.
Purpose of the Study:
- To identify functionally significant mutations in the GR hormone-binding domain responsible for altered glucocorticoid sensitivity.
- To characterize the functional consequences of specific GR mutations.
Main Methods:
- Derived complementary DNA (cDNA) clones for GR mRNA from mutant cells.
- Substituted mutant hormone-binding domain sequences into a GR cDNA expression vector.
- Tested GR protein function via transient expression in COS-7 cells with a reporter gene and varying glucocorticoid concentrations.
Main Results:
- Identified two point mutations in the GR hormone-binding domain.
- A Pro547 to Ala substitution resulted in a GR requiring 100-fold higher hormone concentrations.
- A Cys742 to Gly substitution led to an unstable and largely nonfunctional GR protein.
Conclusions:
- Specific point mutations in the GR hormone-binding domain significantly impact glucocorticoid sensitivity and receptor stability.
- These findings elucidate the molecular basis of altered hormone responses in the W7M320b cell line.
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