Related Experiment Video
Updated: Jun 28, 2026
09:20
Isolation and Differentiation of Adipose-Derived Stem Cells from Porcine Subcutaneous Adipose Tissues
Published on: March 31, 2016
Structural insight into PPARgamma activation through covalent modification with endogenous fatty acids.
Tsuyoshi Waku1, Takuma Shiraki, Takuji Oyama
1Takara Bio Endowed Division, Department of Biomolecular Recognition, Institute for Protein Research, Osaka University, Open Laboratories of Advanced Bioscience and Biotechnology, Suita, Osaka, Japan.
Journal of Molecular Biology
|November 4, 2008
Summary
Peroxisome proliferator-activated receptor (PPAR) gamma activation by fatty acids involves covalent binding to a specific cysteine. Structural changes in the ligand-binding domain, particularly loop conformation, dictate receptor activity and partial agonism.
Area of Science:
- Biochemistry
- Molecular Biology
- Structural Biology
Background:
- Peroxisome proliferator-activated receptor (PPAR) gamma is a key regulator of lipid homeostasis.
- Endogenous fatty acid metabolites act as ligands for PPAR gamma.
- Covalent modification of PPAR gamma is implicated in its activation.
Purpose of the Study:
- To elucidate the structural basis of PPAR gamma activation by covalently bound endogenous fatty acids.
- To understand the mechanism of partial agonism of PPAR gamma ligands.
- To identify novel PPAR gamma agonists.
Main Methods:
- X-ray crystallography to determine the structures of PPAR gamma ligand-binding domain (LBD) complexes.
- Site-directed mutagenesis to assess the role of specific residues in receptor activation.
- In silico screening and cell-based assays for agonist identification.
Main Results:
- Crystal structures revealed covalent binding of fatty acids to a unique cysteine in PPAR gamma LBD.
- Covalent binding induced conformational changes in loop regions and side-chain networks, crucial for activation.
- Distinct loop conformations correlated with varying transcriptional activity of oxidized eicosatetraenoic acids (oxoETEs).
- Novel PPAR gamma agonists were identified through screening and validated by crystallography.
Conclusions:
- PPAR gamma activation by endogenous fatty acids is mediated by covalent modification and subsequent structural alterations.
- Loop conformation within the LBD plays a critical role in modulating PPAR gamma activity.
- This study provides structural insights into PPAR gamma activation and modulation mechanisms.
Related Concept Videos
02:04Covalently Linked Protein Regulators
Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein.
These groups modify specific amino acids in a protein.
02:04Covalently Linked Protein Regulators
Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein.
These groups modify specific amino acids in a protein.
01:31Transducer Mechanism: Nuclear Receptors
Nuclear receptors, or NRs, are unique transcription factors that regulate gene transcription and affect the cellular pathways involved in reproduction, development, or metabolism. Their ability to be stimulated by small lipophilic ligands and control vital cellular processes makes them ideal drug targets. Nearly 10-15% of currently prescribed drugs target these receptors.
About 48 different soluble family members of nuclear receptors are identified that can be divided into two main classes:
About 48 different soluble family members of nuclear receptors are identified that can be divided into two main classes:
02:04Co-activators and Co-repressors
Gene transcription is regulated by the synergistic action of several proteins that form a complex at a gene regulatory site. This is observed in eukaryotes, where the regulation of gene expression is a complex process. Regulatory proteins in eukaryotes can broadly be classified into two types – regulators that bind directly to specific DNA sequences and co-regulators that associate with regulatory proteins but cannot directly bind to the DNA. These co-regulators are further divided into...
02:04Co-activators and Co-repressors
Gene transcription is regulated by the synergistic action of several proteins that form a complex at a gene regulatory site. This is observed in eukaryotes, where the regulation of gene expression is a complex process. Regulatory proteins in eukaryotes can broadly be classified into two types – regulators that bind directly to specific DNA sequences and co-regulators that associate with regulatory proteins but cannot directly bind to the DNA. These co-regulators are further divided into...
01:09GPCRs Regulate Adenylyl Cylase Activity
Some GPCRs transmit signals through adenylyl cyclase (AC), a transmembrane enzyme. AC helps synthesize second messenger cyclic adenosine monophosphate (cAMP). AC catalyzes cyclization reaction and converts ATP to cAMP by releasing a pyrophosphate. The pyrophosphate is further hydrolyzed to phosphate by the enzyme pyrophosphatase, which drives cAMP synthesis to completion. However, cAMP is rapidly degraded to 5′ AMP by the enzymes phosphodiesterase (PDE), preventing overstimulation of cells.
Two...
Two...