Related Experiment Video
Updated: Mar 21, 2026
Author Spotlight: Semi-Automated Isolation of the Stromal Vascular Fraction from Murine White Adipose Tissue Using a Tissue Dissociator
Published on: May 19, 2023
Phosphoprotein network analysis of white adipose tissues unveils deregulated pathways in response to high-fat diet
Asfa Alli Shaik1, Beiying Qiu1, Sheena Wee1
1Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, 61 Biopolis Drive, Singapore 138673, Singapore.
Abstract:
Despite efforts in the last decade, signaling aberrations associated with obesity remain poorly understood. To dissect molecular mechanisms that define this complex metabolic disorder, we carried out global phosphoproteomic analysis of white adipose tissue (WAT) from mice fed on low-fat diet (LFD) and high-fat diet (HFD). We quantified phosphorylation levels on 7696 peptides, and found significant differential phosphorylation levels in 282 phosphosites from 191 proteins, including various insulin-responsive proteins and metabolic enzymes involved in lipid homeostasis in response to high-fat feeding. Kinase-substrate prediction and integrated network analysis of the altered phosphoproteins revealed underlying signaling modulations during HFD-induced obesity, and suggested deregulation of lipogenic and lipolytic pathways. Mutation of the differentially-regulated novel phosphosite on cytoplasmic acetyl-coA forming enzyme ACSS2 (S263A) upon HFD-induced obesity led to accumulation of serum triglycerides and reduced insulin-responsive AKT phosphorylation as compared to wild type ACSS2, thus highlighting its role in obesity. Altogether, our study presents a comprehensive map of adipose tissue phosphoproteome in obesity and reveals many previously unknown candidate phosphorylation sites for future functional investigation.
Insights
Obesity disrupts cell signaling. This study maps protein phosphorylation changes in mouse fat tissue, revealing new targets like ACSS2 that impact lipid metabolism and insulin response.
Area of Science:
- Molecular Biology
- Metabolic Disorders
- Proteomics
Background:
- Signaling pathway dysregulation in obesity is not fully understood.
- White adipose tissue (WAT) plays a critical role in metabolic homeostasis.
- Phosphoproteomics offers a way to study dynamic signaling events.
Purpose of the Study:
- To comprehensively map the phosphoproteome of WAT in diet-induced obesity.
- To identify novel signaling pathways and protein phosphorylation sites involved in obesity.
- To investigate the functional role of specific altered phosphosites in metabolic regulation.
Main Methods:
- Global phosphoproteomic analysis of WAT from mice on low-fat diet (LFD) and high-fat diet (HFD).
- Quantification of phosphorylation levels on thousands of peptides.
- Bioinformatic analysis including kinase-substrate prediction and network analysis.
- Functional validation using site-directed mutagenesis of a key phosphosite on ACSS2.
Main Results:
- Identified significant differential phosphorylation at 282 phosphosites across 191 proteins in response to HFD.
- Revealed alterations in insulin-responsive proteins and enzymes critical for lipid homeostasis.
- Discovered a novel HFD-regulated phosphosite (S263) on ACSS2; mutation led to hypertriglyceridemia and impaired AKT phosphorylation.
- Network analysis suggested deregulation of lipogenic and lipolytic pathways.
Conclusions:
- Provides a detailed phosphoproteomic map of adipose tissue in obesity.
- Identifies ACSS2 phosphorylation as a key regulator in diet-induced obesity.
- Highlights numerous novel candidate phosphorylation sites for future functional studies in metabolic disease.
