Insights into the Regulation of the Glycine Transporter 1 (GlyT1)

深入了解甘氨酸转运蛋白 1 (GlyT1) 的调控

• 批准号: 7907776
• 负责人: Manuel Miranda-Arango
• 金额: $ 22.2万
• 依托单位: UNIVERSITY OF TEXAS EL PASO
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-15 至 2012-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7907776
• 关键词: Biological Assay; Brain; Brain Stem; Cell Line; Cell membrane; Cell surface; Cells; Clinical; D Aspartate; Data; Down-Regulation; Drug Delivery Systems; Endocytosis; Endothelial Cells; Family; Family suidae; Functional disorder; GLYT1; Glutamate Agonist; Glutamate Receptor; Glutamates; Glycine; Glycine Receptors; Goals; Hela Cells; Hippocampus (Brain); Immunofluorescence Immunologic; Immunoprecipitation; Label; Laboratories; Link; Liquid Chromatography; Mass Spectrum Analysis; Membrane Microdomains; Metabolic; Modeling; Mus; N-Methyl-D-Aspartate Receptors; Neurodegenerative Disorders; Neuroglia; Neurons; Neurotransmitters; Pathway interactions; Phosphorylation; Phosphorylation Site; Post-Translational Protein Processing; Protein Kinase C; Proteins; Rattus; Receptor Activation; Regulation; Research; Role; Schizophrenia; Sequence Analysis; Site; Site-Directed Mutagenesis; Small Interfering RNA; Spinal Cord; Strychnine; Symptoms; Synapses; System; Testing; Ubiquitin; Ubiquitination; Western Blotting; base; citrate carrier; cognitive function; dopamine transporter; drug development; glycine transporter; inhibitor/antagonist; insight; member; monoamine; nervous system disorder; neurotransmission; presynaptic; research study; tandem mass spectrometry; trafficking

DESCRIPTION (provided by applicant): Glycine is the major inhibitory neurotransmitter in the brainstem and spinal cord, where it functions at specific strychnine-sensitive glycine receptors. In addition, glycine participates in excitatory neurotransmission as an essential co-agonist of glutamate at N-methyl-D-aspartate (NMDA) receptor containing synapses; therefore, NMDA receptor activation is tightly modulated by the activity of the plasma membrane glycine transporter 1 (GlyT1) present in presynaptic neurons and neighboring glial cells. Altered numbers of functional NMDA receptors have been suggested to underlie some of the symptoms in schizophrenia, primarily in cognitive functions. The GlyT1 has been the main target for drug development in schizophrenia; however, how the transporter is regulated remains poorly understood. It is known for several members of the monoamine transporter family that transport activity is linked to activation of Protein Kinase C (PKC); however, the mechanism of regulation is controversial or unknown in the brain. Given the strength of clinical and pharmacological data suggesting glutamate receptor dysfunction in schizophrenia and the role of the glycine transporter as a potential drug target, in this study our goal is to characterize the regulatory mechanism of the GlyT1 using two expression systems: (a) mouse GlyTIa expressed in model cell lines (HeLa and Porcine Aortic Endothelial cells, PAE) and (b) endogenous GlyT1 in primary cultures from rat hippocampus. Based on preliminary data from our laboratory that suggest enhanced PKC-dependent ubiquitination and endocytosis obtained by expressing GlyT1 in HeLa cells, we hypothesize that PKC activation results in GlyT1 ubiquitination and down-regulation in the brain, contributing to the regulation of the glycine transporter. This research will offer new potential pharmacological targets to treat neurological disorders, such as schizophrenia.

描述（由申请人提供）：甘氨酸是脑干和脊髓中的主要抑制性神经递质，在特定的肾上腺素敏感甘氨酸受体下起作用。此外，甘氨酸也参与兴奋性神经传递，作为N-甲基-D-天冬氨酸（NMDA）受体的谷氨酸的必不可少的共同受体，其中含有突触。因此，NMDA受体激活受到了突触前神经元和邻近神经胶质细胞中存在的质膜1（GLYT1）的活性严格调节。已经提出了功能性NMDA受体数量的改变，这是精神分裂症中一些症状的基础，主要是在认知功能方面。 Glyt1一直是精神分裂症药物开发的主要靶标。但是，如何调节转运蛋白仍然了解得很糟糕。它以单胺转运蛋白家族的几个成员而闻名，即转运活性与蛋白激酶C（PKC）的激活有关。但是，调节机制在大脑中是有争议的或未知的。 Given the strength of clinical and pharmacological data suggesting glutamate receptor dysfunction in schizophrenia and the role of the glycine transporter as a potential drug target, in this study our goal is to characterize the regulatory mechanism of the GlyT1 using two expression systems: (a) mouse GlyTIa expressed in model cell lines (HeLa and Porcine Aortic Endothelial cells, PAE) and (b) endogenous GlyT1在大鼠海马的一级培养物中。基于我们实验室的初步数据表明，通过在HELA细胞中表达Glyt1获得的PKC依赖性泛素化和内吞作用增强，我们假设PKC激活导致Glyt1泛素化和大脑的下调，从而有助于调节甘霉素转运器。这项研究将为治疗神经系统疾病（例如精神分裂症）提供新的潜在药理靶标。