Posttranslational Modifications of Peroxisome Proliferator-activated Receptor γ

Peroxisome proliferator-activated receptor γ ( PPAR γ ) is a member of the nuclear receptor superfamily of ligand-dependent transcription factors. PPAR γ regulates various biological processes such as cell differentiation , lipid metabolism , glucose metabolism and inflammation. It is acknowledged that the transcriptional activity of PPAR γ may be fine-tuned by several mechanisms in vivo . For example , the expression level of PPAR γ , the availability of its ligand and the association between PPAR γ and corepressor / coactivator have been demonstrated to be able to regulate PPAR γ activation. In addition , mounting evidence has defined posttranslational modifications ( PTMs ) as a novel essential factor tightly modulating PPAR γ activation recently. Several PTMs of PPAR γ including phosphorylation , ubiquitination , sumoylation and S-nitrosylation , might regulate its target genes by tuning protein conformation , protein- protein interactions and the affinity between the receptor and ligand. Importantly , there are some potential links between PTMs of PPAR γ and the pathogenesis of several diseases such as diabetes , atherosclerosis and tumor. This review summarized the main characteristics of several PTMs of PPAR γ , and highlighted the significance of PTMs in the occurrence , development and treatment of diseases.