Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA.
Sarafan ChEM-H, Stanford University, Stanford, CA, USA.
Nature. 2024 Sep;633(8028):182-188. doi: 10.1038/s41586-024-07801-6. Epub 2024 Aug 7.
Taurine is a conditionally essential micronutrient and one of the most abundant amino acids in humans. In endogenous taurine metabolism, dedicated enzymes are involved in the biosynthesis of taurine from cysteine and in the downstream metabolism of secondary taurine metabolites. One taurine metabolite is N-acetyltaurine. Levels of N-acetyltaurine are dynamically regulated by stimuli that alter taurine or acetate flux, including endurance exercise, dietary taurine supplementation and alcohol consumption. So far, the identities of the enzymes involved in N-acetyltaurine metabolism, and the potential functions of N-acetyltaurine itself, have remained unknown. Here we show that the body mass index associated orphan enzyme phosphotriesterase-related (PTER) is a physiological N-acetyltaurine hydrolase. In vitro, PTER catalyses the hydrolysis of N-acetyltaurine to taurine and acetate. In mice, PTER is expressed in the kidney, liver and brainstem. Genetic ablation of Pter in mice results in complete loss of tissue N-acetyltaurine hydrolysis activity and a systemic increase in N-acetyltaurine levels. After stimuli that increase taurine levels, Pter knockout mice exhibit reduced food intake, resistance to diet-induced obesity and improved glucose homeostasis. Administration of N-acetyltaurine to obese wild-type mice also reduces food intake and body weight in a GFRAL-dependent manner. These data place PTER into a central enzymatic node of secondary taurine metabolism and uncover a role for PTER and N-acetyltaurine in body weight control and energy balance.
牛磺酸是一种条件必需的微量营养素,也是人体内最丰富的氨基酸之一。在牛磺酸的内源性代谢中,专门的酶参与牛磺酸从半胱氨酸的生物合成以及次级牛磺酸代谢物的下游代谢。一种牛磺酸代谢物是 N-乙酰牛磺酸。N-乙酰牛磺酸的水平受改变牛磺酸或乙酸盐通量的刺激而动态调节,包括耐力运动、饮食牛磺酸补充和饮酒。到目前为止,参与 N-乙酰牛磺酸代谢的酶的身份以及 N-乙酰牛磺酸本身的潜在功能仍然未知。在这里,我们表明与体重指数相关的孤儿酶磷酸三酯酶相关(PTER)是一种生理 N-乙酰牛磺酸水解酶。在体外,PTER 催化 N-乙酰牛磺酸水解为牛磺酸和乙酸盐。在小鼠中,PTER 在肾脏、肝脏和脑干中表达。在小鼠中敲除 Pter 会导致组织 N-乙酰牛磺酸水解活性完全丧失和系统内 N-乙酰牛磺酸水平升高。在增加牛磺酸水平的刺激后,Pter 敲除小鼠表现出食物摄入量减少、对饮食诱导肥胖的抵抗力增强和葡萄糖稳态改善。给予肥胖野生型小鼠 N-乙酰牛磺酸也以 GFRAL 依赖的方式减少食物摄入和体重。这些数据将 PTER 置于次级牛磺酸代谢的中央酶学节点,并揭示了 PTER 和 N-乙酰牛磺酸在体重控制和能量平衡中的作用。