Qiu Zhiwei, Jiang Tao, Shao Guangying, Yang Baoxue
Institute of Clinical Pharmacology, Peking University First Hospital, Beijing, China.
College of Basic Medicine, Beihua University, Jilin, China.
Subcell Biochem. 2025;118:105-125. doi: 10.1007/978-981-96-6898-4_6.
Urea transporters (UTs) are a group of membrane channel proteins that specifically facilitate the permeation of urea, which play an essential role in urea reabsorption and water conservation. There are 4 isoforms, UT-A1, UT-A2, UT-A3, UT-B, that are expressed in the kidney to maintain the urea recycle and establish the urea concentration gradient in the medulla, which is essential for the urinary concentration capacity of the kidney. Outside the kidney, widely distributed UT-B and some UT-A isoforms directly participate in regulating signaling transduction and determining cell fate by regulating osmotic pressure, arginine metabolism, and protein carbamylation in various systems. In recent years, studies on different UT knockout mouse models revealed multiple physiological roles of UTs. This chapter summarizes the physiological functions of UTs, including the blood system, urinary system, nervous system, circulatory system, digestive system, auditory system, visual system, reproductive system, and skeletal system.
尿素转运蛋白（UTs）是一类膜通道蛋白，可特异性促进尿素的通透，在尿素重吸收和水的保存中发挥重要作用。有4种亚型，即UT-A1、UT-A2、UT-A3、UT-B，它们在肾脏中表达以维持尿素循环并在髓质中建立尿素浓度梯度，这对肾脏的尿液浓缩能力至关重要。在肾脏外，广泛分布的UT-B和一些UT-A亚型通过调节渗透压、精氨酸代谢以及各种系统中的蛋白质氨甲酰化，直接参与调节信号转导和决定细胞命运。近年来，对不同UT基因敲除小鼠模型的研究揭示了UTs的多种生理作用。本章总结了UTs的生理功能，包括血液系统、泌尿系统、神经系统、循环系统、消化系统、听觉系统、视觉系统、生殖系统和骨骼系统。
