FGF21 receptor

Class

FGF21 analog

FGF21 (fibroblast growth factor 21) is a hormone-like signaling protein produced mainly by the liver that acts on a receptor complex formed by FGFR1c, a member of the fibroblast growth factor receptor family, together with an obligatory co-receptor called beta-klotho. This co-receptor requirement restricts FGF21 signaling to tissues that express beta-klotho, chiefly adipose tissue, liver, and regions of the central nervous system. Physiologically, FGF21 is released during metabolic stress, such as fasting or high sugar and fat intake, and it coordinates changes in glucose handling, fat breakdown, and energy expenditure. Because of these actions, the FGF21 pathway has become a target for treating metabolic and liver diseases, including conditions marked by excess fat accumulation in the liver and impaired insulin sensitivity. Native FGF21 has a very short half-life in circulation and is prone to enzymatic degradation, which limits its usefulness as a therapeutic in its natural form. To address this, drug developers create modified versions, such as fusion proteins that combine an FGF21-like sequence with a stabilizing protein domain, allowing sustained receptor engagement with less frequent dosing. Such FGF21 receptor agonists aim to reproduce the beneficial metabolic effects of the natural hormone across the affected tissue types.