Liu H Y, Wei X S, Dai W T, Xu L B, Wang C, Liu J X
College of Animal Sciences, Zhejiang University, Hangzhou 310058, P.R. China.
College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou 311300, China.
JDS Commun. 2023 Feb 24;4(3):235-239. doi: 10.3168/jdsc.2022-0292. eCollection 2023 May.
Free and peptide-bound AA act as building blocks and key regulators of milk protein. To improve milk protein production, mammary epithelial cells of lactating mammals require extensive AA movement across the plasma membrane via multiple transport systems. Recent studies on bovine mammary cells/tissues have expanded the number of AA transporter systems identified and the knowledge on their contribution to AA utilization for milk protein synthesis and the regulatory machinery. However, in lactating cows, the exact intracellular location of mammary AA transporters and the extent of mammary net AA utilization for milk protein production remain unclear. This review highlights the existing knowledge on various characteristics, such as substrate specificity, kinetics, their effects on AA uptake and utilization, and regulatory mechanism, of recently examined bovine mammary free and peptide-bound AA transporters.
游离氨基酸和肽结合氨基酸作为乳蛋白的组成成分和关键调节因子。为提高乳蛋白产量，泌乳哺乳动物的乳腺上皮细胞需要通过多种转运系统使大量氨基酸跨质膜转运。最近对牛乳腺细胞/组织的研究增加了已鉴定的氨基酸转运系统数量，并增进了对它们在乳蛋白合成氨基酸利用及调节机制中所起作用的了解。然而，在泌乳奶牛中，乳腺氨基酸转运体的确切细胞内定位以及乳腺用于乳蛋白生产的净氨基酸利用程度仍不清楚。本综述着重介绍了最近研究的牛乳腺游离氨基酸和肽结合氨基酸转运体的各种特性，如底物特异性、动力学、它们对氨基酸摄取和利用的影响以及调节机制等方面的现有知识。
