Phosphoenolpyruvate carboxykinase 2 (PCK2) attenuates bovine adipocyte lipolysis through PNPLA2 activity repression

Marbling traits serve as a key determinant of meat quality in livestock, with interspecies genetic variations significantly influencing intramuscular fat (IMF) deposition. Through systematic analysis of public databases and cross-species RNA sequencing data from cattle, sheep, and pigs exhibiting divergent IMF levels, we identified PCK2 as a conserved regulatory factor governing lipogenesis. Functional analyses demonstrated that targeted PCK2 silencing significantly impaired cell cycle dynamics and suppressed adipocyte proliferation, which mechanistically involved transcriptional downregulation of key cell cycle regulators (CCNB1, CCND1, CCNE2) and functional inhibition of critical proliferative mediators (CDK1, CDK2, PCNA). Furthermore, PCK2 silencing impaired lipid accumulation by decreasing triglyceride synthesis and lipid droplet formation, while down-regulating adipogenic transcription factors PPARγ and C/EBPα, as well as lipid metabolism factors SCD1, ACSL1 and FABP4. Integrated multi-omics analysis revealed PCK2 modulates bovine IMF deposition through the regulation of lipolysis in adipocyte. Notably, patatin-like phospholipase domain containing 2 (PNPLA2) suppression as a novel mechanism underlying PCK2-mediated enhancement of bovine intramuscular adipocyte differentiation. These findings establish a molecular framework for understanding PCK2’s regulatory role in marbling beef production.

AbstractSection Graphical Abstract