Polyamine-modulated factor 1 represses glucocorticoid receptor activity.

Polyamine-modulated factor 1 (PMF-1) has been reported to interact with NF-E2 related factor 2 (Nrf-2) and activate the polyamine-induced transcription of spermidine/spermine N(1)-acetyltransferase (SSAT) gene. Polyamines are important regulators of cell growth and cell death and have been implicated in glucocorticoid-induced apoptosis. In the present study, we have identified and characterized new functional binding partners for PMF-1.

Molecular basis for repression of liver X receptor-mediated gene transcription by receptor-interacting protein 140.

Similarities in physiological roles of LXR (liver X receptors) and co-repressor RIP140 (receptor-interacting protein 140) in regulating energy homoeostasis and lipid and glucose metabolism suggest that the effects of LXR could at least partly be mediated by recruitment of the co-repressor RIP140. In the present study, we have elucidated the molecular basis for regulation of LXR transcriptional activity by RIP140. LXR is evenly localized in the nucleus and neither the N-terminal domain nor the LBD (ligand-binding domain) is necessary for nuclear localization.

Functional interaction between the glucocorticoid receptor and GANP/MCM3AP.

Glucocorticoids are widely used to treat inflammatory diseases but have a number of side effects that partly are connected to inhibition of cell proliferation. Glucocorticoids mediated their action by binding to the glucocorticoid receptor. In the present study, we have identified by two-hybrid screens the germinal center-associated protein (GANP) and MCM3-associated protein (MCM3AP), a splicing variant of GANP, as glucocorticoid receptor interacting proteins.

Regulation of subnuclear localization is associated with a mechanism for nuclear receptor corepression by RIP140.

Regulation of gene transcription by nuclear receptors involves association with numerous coregulators. Receptor-interacting protein 140 (RIP140) is a corepressor that negatively regulates the ligand-induced activity of several nuclear receptors, including the glucocorticoid receptor (GR). In the present study, we have characterized the role of the intranuclear localization of RIP140 in its corepressor activity.