Alterations in glucocorticoid receptor conformation by molybdate

Area of Science:

• Biochemistry
• Molecular Biology
• Endocrinology

Background:

• Glucocorticoid receptors (GRs) play crucial roles in regulating gene expression.
• Maintaining the stability and conformation of GRs is essential for their function.
• Lactating mammary glands are a key tissue for studying hormonal regulation.

Purpose of the Study:

• To investigate the effect of molybdate on the stability of glucocorticoid receptor activity.
• To determine the impact of molybdate on the sedimentation properties of the glucocorticoid receptor.
• To elucidate the mechanism by which molybdate stabilizes the glucocorticoid receptor.

Main Methods:

• Preparation of cytosol from lactating rat mammary glands.
• Incubation of cytosol with and without sodium molybdate (Na2MoO4).
• Sucrose density gradient centrifugation to determine sedimentation coefficients.

Main Results:

• Molybdate significantly stabilized glucocorticoid receptor activity against inactivation at 25°C.
• The sedimentation coefficient of the glucocorticoid receptor was 9-10S in the presence of 10 mM Na2MoO4.
• In the absence of molybdate, the sedimentation coefficient was 6-7S.

Conclusions:

• Molybdate directly interacts with the glucocorticoid receptor.
• These interactions induce conformational changes that stabilize the receptor.
• Molybdate is a valuable tool for preserving glucocorticoid receptor integrity in biochemical studies.