Trbl

The Trbl group comprises the mammalian Tribbles proteins TRIB1, TRIB2, and TRIB3, pseudokinases that lack catalytic activity but serve as dynamic scaffolds. A degraded kinase domain is flanked by a MEK1-binding region and a C-terminal COP1-binding motif that recruits the E3 ubiquitin ligase to substrates. TRIB1 controls lipid metabolism and macrophage differentiation by promoting C/EBP alpha degradation, and common variants near TRIB1 raise plasma triglycerides and coronary artery disease risk. TRIB2 cooperates in acute myeloid leukemia and lung tumorigenesis, while endoplasmic reticulum stress-inducible TRIB3 modulates AKT signaling, insulin action, and glucose production, linking this family to cardiometabolic disease and cancer.