Proteomic Analysis of Steady-State Nuclear Hormone Receptor Coactivator Complexes

Abstract

We report our initial efforts in the analysis of endogenous nuclear receptor coactivator complexes as a research bridging strand of the Nuclear Receptor Signaling Atlas (NURSA) (www.NURSA.org). A proteomic approach is used to systematically isolate a variety of coactivator complexes using HeLa cells as a model cell line and to identify the coactivator-associated proteins with mass spectrometry. We have isolated and identified seven coactivator complexes including the p160 steroid receptor coactivator family, cAMP response element binding protein-binding protein, p300, coactivator of activating protein-1 and estrogen receptors, and E6 papillomavirus-associated protein. The newly identified coactivator-associated proteins provide unbiased clues and links for understanding of the endogenous hormone receptor coregulator network and its regulation. We hope that the electronic availability of these data to the general scientific community will facilitate generation and testing of new hypotheses to further our understanding of nuclear receptor signaling and coactivator functions.

Resveratrol modulates the inflammatory response via an estrogen receptor-signal integration network

“…SRC1 and SRC3 played ligand-independent roles, while SRC2 and SRC3 were more specifically required for repression by E2 and resveratrol. These differences are likely due to the different transient, multi-protein complexes formed by these promiscuous coregulators (Stenoien et al, 2001; Jung et al, 2005; Malovannaya et al, 2011). For example, the mouse ortholog of SRC2, called GRIP1, was found to have an additional role in glucocorticoid-mediated repression of inflammatory genes (Rogatsky et al, 2002), which mapped to a binding site for a trimethyltransferase, Suv4-20h1, an enzyme that represses glucocorticoid receptor activity (Chinenov et al, 2008).…”

Ubiquitylation of nuclear receptors: new linkages and therapeutic implications

“…The activated NR transcriptional complexes include co-regulators (activators and repressors), chromatin modifying and remodeling complexes, and components of the basal transcriptional machinery. To date, over 300 NR co-regulators have been identified (Jung et al 2005; Malovannaya et al 2011; www.nursa.org). Ligand activation of membrane receptors couples receptor activation to intracellular signaling cascades (Hammes & Levin 2011).…”

Global Characterization of Transcriptional Impact of the SRC-3 Coregulator

“…Nuclear extracts from cycling (DMEM with phenol red; 5% FBS), vehicle-treated, or E2-treated (10 Ϫ8 M for 2 h in DMEM without phenol red, 5% charcoal-stripped FBS) MCF-7 cells were prepared using modified Dignam's method essentially as described (68). All buffers in this procedure were supplemented freshly with 10 mM ␤-mercaptoethanol and protease inhibitor cocktail (phenylmethylsulfonyl fluoride, pepstatin A, leupeptin, and benzamidine).…”