Transcriptional ERRγ2-mediated activation is regulated by sentrin-specific proteases

Abstract

Modification with small ubiquitin-like modifiers (SUMOs) has emerged as an important means of regulating the activity of transcription factors, often by repressing their activity. The estrogen receptor-related receptor γ (ERRγ, ERR3, NR3B3) is a constitutively active orphan nuclear receptor. A phosphorylation-dependent sumoylation motif (PDSM) is located in close vicinity of the amino-terminally located ERRγ2-specific activation function 1 (AF-1). Its function can be substituted by a negatively charged amino aciddependent sumoylation motif (NDSM). A mutational analysis reveals that ERRγ2-activity is modulated through sumoylation of a lysine residue at position 40 which in turn is regulated by phosphorylation. Phosphorylation in the +5-position relative to the sumoylation target is directly visualized by a high resolution electrophoretic mobility shift assay (EMSA). Sumoylation represses the activity of ERRγ both, with and without forced expression of the peroxisome proliferator-activated receptor gamma coactivator 1β (PGC-1β). Fusion proteins of a heterologous DNA binding domain with the ERRγ2 amino terminus demonstrate the function of the PDSM as the repression function 1 (RF-1) for the neighboring AF-1. Derepression is achieved by coexpression of Sentrin/SUMO-specific protease (SENP) family members. Together, our results demonstrate reversible phosphorylation-dependent sumoylation as a means to regulate the activity of an orphan nuclear receptor.

Divergent regulation of theOsteopontinpromoter by the estrogen receptor-related receptors is isoform- and cell context dependent

“…2;Zirngibl et al, 2008]. We also observed that the activity of mEsrrg2 was higher than that of mEsrrg1 which was unexpected as the sumoylated form of Esrrg2 has been shown to act as a repressor of transcription [Tremblay et al, 2008;Hentschke et al, 2009]. However, in these reported studies the activity was never directly compared between Esrrg1 and Esrrg2.…”

“…Two protein isoforms for Esrrg have been described differing by 29 amino acids at the N-terminus [Hong et al, 1999;Susens et al, 2000]. The additional amino acids in Esrrg2 contain a phosphorylation dependant sumoylation site, which affects the transcriptional activity of the protein [Tremblay et al, 2008;Hentschke et al, 2009]. Esrrg has recently also been shown to be able to regulate the Esrra promoter, adding another layer of complexity [Zhang and Teng, 2007].…”

The adaptor protein PICK1 targets the sorting receptor SorLA

“…To generate VP16 fusion proteins, PICK1 or PSD95 cDNA was cloned in frame via BamHI and NotI into pAct (Promega). To express GAL4 fusion proteins cDNA encoding wild-type or mutant cytoplasmic domains of SorLA or Sortilin were cloned in frame via BamHI and NotI into pBind3-D [ 64 ]. Mutations in the amino acid sequence of the SorLA cytoplasmic domain were introduced by PCR using appropriate primers.…”

Impaired Repressor Function in SUMOylation-Defective Thyroid Hormone Receptor Isoforms

“…nuclear receptors) and transcriptional cofactors (e.g. coactivators and corepressors) are verified targets of SUMOylation [20,21,22,23]. With this study, I demonstrate that SUMOylation of TRα and TRβ is capable of fine-tuning its corresponding transcriptional activity.…”