Small-molecule inhibition of the deadenylase CNOT6L as a strategy of obesity treatment

Obesity, driven by systemic energy imbalance, remains a critical health challenge. The deadenylase CNOT6L, a key regulator of the hepatokines GDF15 and FGF21, which govern energy balance by suppressing appetite and increasing energy expenditure, respectively, has emerged as a promising anti-obesity strategy. Pharmacologically targeting CNOT6L therefore represents a promising dual-pathway strategy for obesity treatment, yet no potent and selective inhibitors have been reported. Here, we describe the discovery of YL-333P, a first-in-class, highly potent, and selective small-molecule inhibitor of CNOT6L. The co-crystal structure of YL-333P in complex with CNOT6L elucidates the molecular basis of its high potency. YL-333P potently upregulated GDF15 and FGF21 expression in vitro and in vivo . In diet-induced obese (DIO) mice, pharmacological CNOT6L inhibition with YL-333P reduced body weight and improved metabolic health—notably enhancing insulin sensitivity and reducing hepatic steatosis. These benefits were mediated by the concurrent stimulation of anorexigenic GDF15 signaling and FGF21-driven energy expenditure. Collectively, our findings establish YL-333P as a novel chemical tool and demonstrate that small-molecule inhibition of CNOT6L represents a viable and promising therapeutic strategy for the treatment of obesity. YL-333P, a potent and selective first-in-class CNOT6L inhibitor, combats obesity in DIO mice by elevating GDF15/FGF21 to suppress appetite and increase energy expenditure, thereby reducing weight and improving metabolic dysfunction.