TY - JOUR
T1 - Transcription coactivators for peroxisome proliferator-activated receptors
AU - Yu, Songtao
AU - Reddy, Janardan K.
N1 - Funding Information:
We regret for not being able to include all the references from our colleagues due to the space limit of this review. We thank past and present members of the Reddy Laboratory for their scientific contributions reviewed in this manuscript. This work was supported by NIH Grants R01 CA104578 and GM23750, and Joseph l. Mayberry, Sr., Endowment Fund, Northwestern University.
PY - 2007/8
Y1 - 2007/8
N2 - Peroxisome proliferator-activated receptors (PPARs) regulate diverse biological processes such as development, differentiation, neoplastic conversion, inflammation and wound healing in addition to their critical roles in energy (lipid and carbohydrate) metabolism. Unliganded PPARs heterodimerize with retinoid X receptor α and repress transcription when bound to DNA by interacting with corepressor molecules. Upon canonical ligand binding, PPARs manifest conformational changes that facilitate the dissociation of corepressor molecules to enable a spatiotemporally orchestrated recruitment (association) of coactivators and coactivator-associated proteins to the liganded receptor. Functional significance for the existence of over 200 nuclear receptor cofactors is not readily evident, but emerging gene knockout mouse models show that some of the coactivators are essential for embryonic growth and survival and for controlling receptor specific target gene expression in a cell specific need based demands. Coactivators contain one or more highly conserved LXXLL amphiphatic α-helix motif, called nuclear receptor box, for direct interaction with the activation function 2 (AF-2) regions in nuclear receptors. PPARs interact with large multisubunit coactivator protein complexes, some exhibiting intrinsic histone acetyltransferase or methyltransferase activity, while others functioning as facilitators of ATP-dependent chromatin remodeling or as linkers to the basal transcription machinery. While the dynamic and coordinated changes in nuclear receptor expression and differences in the nature of their key target genes are important, it is becoming increasingly evident that perturbations in the expression of coactivators may affect the function of many nuclear receptors including PPARs. Tissue specific differences in coactivator expression add another dimension to the complexity of gene- and cell-specific transcriptional regulation. Identification of PPAR specific coactivators should further our understanding of the complexities of metabolic diseases associated with energy metabolism.
AB - Peroxisome proliferator-activated receptors (PPARs) regulate diverse biological processes such as development, differentiation, neoplastic conversion, inflammation and wound healing in addition to their critical roles in energy (lipid and carbohydrate) metabolism. Unliganded PPARs heterodimerize with retinoid X receptor α and repress transcription when bound to DNA by interacting with corepressor molecules. Upon canonical ligand binding, PPARs manifest conformational changes that facilitate the dissociation of corepressor molecules to enable a spatiotemporally orchestrated recruitment (association) of coactivators and coactivator-associated proteins to the liganded receptor. Functional significance for the existence of over 200 nuclear receptor cofactors is not readily evident, but emerging gene knockout mouse models show that some of the coactivators are essential for embryonic growth and survival and for controlling receptor specific target gene expression in a cell specific need based demands. Coactivators contain one or more highly conserved LXXLL amphiphatic α-helix motif, called nuclear receptor box, for direct interaction with the activation function 2 (AF-2) regions in nuclear receptors. PPARs interact with large multisubunit coactivator protein complexes, some exhibiting intrinsic histone acetyltransferase or methyltransferase activity, while others functioning as facilitators of ATP-dependent chromatin remodeling or as linkers to the basal transcription machinery. While the dynamic and coordinated changes in nuclear receptor expression and differences in the nature of their key target genes are important, it is becoming increasingly evident that perturbations in the expression of coactivators may affect the function of many nuclear receptors including PPARs. Tissue specific differences in coactivator expression add another dimension to the complexity of gene- and cell-specific transcriptional regulation. Identification of PPAR specific coactivators should further our understanding of the complexities of metabolic diseases associated with energy metabolism.
KW - Gene-knockout mouse model
KW - PBP/TRAP220/MED1
KW - PPARα,-β/δ or -γ
KW - Transcriptional coactivator
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U2 - 10.1016/j.bbalip.2007.01.008
DO - 10.1016/j.bbalip.2007.01.008
M3 - Review article
C2 - 17306620
AN - SCOPUS:34547604561
VL - 1771
SP - 936
EP - 951
JO - BBA - Specialised Section On Lipids and Related Subjects
JF - BBA - Specialised Section On Lipids and Related Subjects
SN - 1388-1981
IS - 8
ER -