Expression of urea transporters and their regulation.
Expression of urea transporters and their regulation.
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DOI：
10.1007/978-94-017-9343-8_6
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发表时间：
2014
影响因子：
--
通讯作者：
J. Klein
中科院分区：
文献类型：
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作者：
J. Klein
尿素转运蛋白的UT-A和UT-B家族由多种亚型组成，这些亚型受到急性和长期措施的调节。本章简要概述了尿素转运蛋白的表达形式及其在肾脏中的位置。UT-A1的快速调节是由磷酸化和膜积累的组合引起的。UT-A1的磷酸化与加压素和高渗有关，尽管是通过不同的激酶。对尿素转运蛋白活性的其他急性影响是泛素化和糖基化，这两者都通过不同的机制影响尿素转运蛋白的膜结合。尿素转运的长期调节与肾脏所经历的环境密切相关。低蛋白饮食可能影响可用的尿素转运蛋白的量。渗透性利尿条件下，尿素浓度低，将促使尿素转运蛋白丰度增加。虽然肾上腺皮质激素影响尿素转运蛋白的丰度，但相互矛盾的报道使结论变得脆弱。当P2Y2嘌呤能受体减少时，尿素转运蛋白上调，表明这些受体在UT调节中的作用。高钙血症和低钾血症都会引起尿浓缩不足。尿素转运蛋白丰度在老龄动物和血管紧张素转换酶缺乏的动物中减少。本章将提供有关尿素转运蛋白的快速和长期调节的信息，并提供文献介绍。
UT-A and UT-B families of urea transporters consist of multiple isoforms that are subject to regulation of both acutely and by long-term measures. This chapter provides a brief overview of the expression of the urea transporter forms and their locations in the kidney. Rapid regulation of UT-A1 results from the combination of phosphorylation and membrane accumulation. Phosphorylation of UT-A1 has been linked to vasopressin and hyperosmolality, although through different kinases. Other acute influences on urea transporter activity are ubiquitination and glycosylation, both of which influence the membrane association of the urea transporter, again through different mechanisms. Long-term regulation of urea transport is most closely associated with the environment that the kidney experiences. Low-protein diets may influence the amount of urea transporter available. Conditions of osmotic diuresis, where urea concentrations are low, will prompt an increase in urea transporter abundance. Although adrenal steroids affect urea transporter abundance, conflicting reports make conclusions tenuous. Urea transporters are upregulated when P2Y2 purinergic receptors are decreased, suggesting a role for these receptors in UT regulation. Hypercalcemia and hypokalemia both cause urine concentration deficiencies. Urea transporter abundances are reduced in aging animals and animals with angiotensin-converting enzyme deficiencies. This chapter will provide information about both rapid and long-term regulation of urea transporters and provide an introduction into the literature.