Functional interaction between the glucocorticoid receptor and GANP/MCM3AP.

Area of Science:

• Cell Biology
• Molecular Biology
• Endocrinology

Background:

• Glucocorticoids treat inflammatory diseases but cause side effects linked to inhibited cell proliferation.
• Glucocorticoid action is mediated by binding to the glucocorticoid receptor.
• Understanding glucocorticoid receptor interactions is crucial for managing side effects.

Purpose of the Study:

• Identify novel proteins interacting with the glucocorticoid receptor.
• Investigate the role of these interactions in glucocorticoid-mediated cell proliferation.
• Elucidate the mechanism by which glucocorticoids affect cell division.

Main Methods:

• Two-hybrid screens to identify interacting proteins.
• Glutathione-S-transferase pull-down and co-immunoprecipitation assays.
• Cellular localization studies and functional assays in HeLa cells.

Main Results:

• Identified germinal center-associated protein (GANP) and its splicing variant MCM3-associated protein (MCM3AP) as glucocorticoid receptor interacting proteins.
• Demonstrated interaction between the C-terminal domain of GANP (including MCM3AP) and the ligand-binding domain of the glucocorticoid receptor.
• Showed that overexpression of MCM3AP prevents glucocorticoid-induced inhibition of DNA replication in HeLa cells.

Conclusions:

• GANP and MCM3AP are novel glucocorticoid receptor interacting proteins.
• The GANP/MCM3AP complex plays a role in regulating cell proliferation in response to glucocorticoids.
• Targeting the glucocorticoid receptor-GANP/MCM3AP interaction may offer therapeutic strategies to mitigate glucocorticoid side effects.