Department for Anesthesiology and Intensive Care, Faculty of Medicine, University of Leipzig, Liebigstraße 20, D-04103 Leipzig, Germany.
Department for Anesthesiology, University Medical Center, Georg-August University, Humboldtallee 23, D-37073 Göttingen, Germany.
Int J Mol Sci. 2022 Feb 25;23(5):2561. doi: 10.3390/ijms23052561.
In addition to being involved in protein biosynthesis and metabolism, the amino acid glycine is the most important inhibitory neurotransmitter in caudal regions of the brain. These functions require a tight regulation of glycine concentration not only in the synaptic cleft, but also in various intracellular and extracellular compartments. This is achieved not only by confining the synthesis and degradation of glycine predominantly to the mitochondria, but also by the action of high-affinity large-capacity glycine transporters that mediate the transport of glycine across the membranes of presynaptic terminals or glial cells surrounding the synapses. Although most cells at glycine-dependent synapses express more than one transporter with high affinity for glycine, their synergistic functional interaction is only poorly understood. In this review, we summarize our current knowledge of the two high-affinity transporters for glycine, the sodium-dependent glycine transporters 1 (GlyT1; SLC6A9) and 2 (GlyT2; SLC6A5) and the alanine-serine-cysteine-1 transporter (Asc-1; SLC7A10).
除了参与蛋白质生物合成和代谢外，氨基酸甘氨酸还是脑尾部最重要的抑制性神经递质。这些功能不仅需要在突触间隙，还需要在各种细胞内和细胞外隔室中严格调节甘氨酸浓度。这不仅通过将甘氨酸的合成和降解主要局限于线粒体来实现，还通过高亲和力大容量甘氨酸转运体的作用来实现，该转运体介导甘氨酸穿过突触前末梢或围绕突触的神经胶质细胞的膜的运输。尽管依赖甘氨酸的突触中的大多数细胞表达一种以上对甘氨酸具有高亲和力的转运体，但它们的协同功能相互作用仍知之甚少。在这篇综述中，我们总结了我们目前对两种高亲和力甘氨酸转运体的了解，即钠离子依赖性甘氨酸转运体 1（GlyT1；SLC6A9）和 2（GlyT2；SLC6A5）以及丙氨酸-丝氨酸-半胱氨酸-1 转运体（Asc-1；SLC7A10）。
