Fibroblast growth factor 21 receptor complex (FGF21 receptor complex)

The fibroblast growth factor 21 receptor complex is a cell-surface multimeric receptor assembly composed of a fibroblast growth factor receptor (typically FGFR1c but also can include FGFR2c, FGFR3c, FGFR4 depending on tissue context) and the co-receptor β-Klotho (KLB). This complex binds the hormone FGF21, which is secreted primarily by the liver in response to metabolic stress and nutrient signals, then circulates and acts as an endocrine factor. FGF21 requires both its binding to FGFR isoforms and to β-Klotho for receptor activation and robust signal transduction. The receptor complex transduces signals via tyrosine kinase–dependent cascades, particularly MAPK/ERK, influencing energy expenditure, glucose uptake, insulin sensitivity, and lipid metabolism. It is a major therapeutic target for diseases such as obesity, type 2 diabetes, and nonalcoholic steatohepatitis (NASH), with several FGF21 analogues in clinical development. No significant spelling errors or conceptual inaccuracies are present in the canonical target name.

Other names

FGF21-KLB-FGFR complexFGF21/FGFR1c/β-Klotho complexFGF21 signaling complex

Agonists: stimulate receptor complex to activate downstream MAPK/ERK signaling and metabolic effects (improve insulin sensitivity, promote weight loss, regulate lipid levels) Antagonists: block FGF21 binding and signaling