6lxa
X-ray structure of human PPARalpha ligand binding domain-eicosapentaenoic acid (EPA) co-crystals obtained by delipidation and cross-seeding
Structural highlights
FunctionPPARA_HUMAN Ligand-activated transcription factor. Key regulator of lipid metabolism. Activated by the endogenous ligand 1-palmitoyl-2-oleoyl-sn-glycerol-3-phosphocholine (16:0/18:1-GPC). Activated by oleylethanolamide, a naturally occurring lipid that regulates satiety (By similarity). Receptor for peroxisome proliferators such as hypolipidemic drugs and fatty acids. Regulates the peroxisomal beta-oxidation pathway of fatty acids. Functions as transcription activator for the ACOX1 and P450 genes. Transactivation activity requires heterodimerization with RXRA and is antagonized by NR2C2.[1] [2] [3] [4] Publication Abstract from PubMedMost triacylglycerol-lowering fibrates have been developed in the 1960s-1980s before their molecular target, peroxisome proliferator-activated receptor alpha (PPARalpha), was identified. Twenty-one ligand-bound PPARalpha structures have been deposited in the Protein Data Bank since 2001; however, binding modes of fibrates and physiological ligands remain unknown. Here we show thirty-four X-ray crystallographic structures of the PPARalpha ligand-binding domain, which are composed of a "Center" and four "Arm" regions, in complexes with five endogenous fatty acids, six fibrates in clinical use, and six synthetic PPARalpha agonists. High-resolution structural analyses, in combination with coactivator recruitment and thermostability assays, demonstrate that stearic and palmitic acids are presumably physiological ligands; coordination to Arm III is important for high PPARalpha potency/selectivity of pemafibrate and GW7647; and agonistic activities of four fibrates are enhanced by the partial agonist GW9662. These results renew our understanding of PPARalpha ligand recognition and contribute to the molecular design of next-generation PPAR-targeted drugs. PPARalpha Ligand-Binding Domain Structures with Endogenous Fatty Acids and Fibrates.,Kamata S, Oyama T, Saito K, Honda A, Yamamoto Y, Suda K, Ishikawa R, Itoh T, Watanabe Y, Shibata T, Uchida K, Suematsu M, Ishii I iScience. 2020 Oct 23;23(11):101727. doi: 10.1016/j.isci.2020.101727. eCollection, 2020 Nov 20. PMID:33205029[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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