Phosphorylation of PPARs: from molecular characterization to physiological relevance

Area of Science:

• Molecular biology
• Cellular signaling
• Biochemistry

Background:

• Nuclear receptors, such as PPARs, are critical regulators of gene expression.
• Ligand binding is a primary mechanism for nuclear receptor activation.
• Post-translational modifications, like phosphorylation, also significantly influence nuclear receptor function.

Purpose of the Study:

• To explore the role of phosphorylation in regulating Peroxisome proliferator-activated receptor (PPAR) activity.
• To detail the kinases involved in PPAR phosphorylation.
• To discuss the molecular and physiological consequences of PPAR phosphorylation.

Main Methods:

• Review of existing literature on PPAR phosphorylation.
• Analysis of kinase-mediated signaling pathways affecting PPARs.
• Discussion of experimental evidence regarding PPAR phosphorylation's effects.

Main Results:

• PPARs are phosphorylated by various kinases, including Protein Kinase A (PKA), Protein Kinase C (PKC), Mitogen-Activated Protein Kinases (MAPKs), and AMP-activated Protein Kinase (AMPK).
• Phosphorylation influences PPAR activity in both ligand-dependent and ligand-independent ways, varying by PPAR isoform and cellular context.
• Consequences include altered ligand affinity, DNA binding, co-regulator recruitment, and protein degradation.

Conclusions:

• Phosphorylation is a key regulatory mechanism for PPARs, fine-tuning their transcriptional activity.
• Understanding PPAR phosphorylation is crucial for deciphering their diverse physiological roles.
• Targeting PPAR phosphorylation may offer therapeutic strategies.