Regulation of Vesicular Glutamate Transport

囊泡谷氨酸运输的调节

• 批准号: 6815212
• 负责人: Susan M. Voglmaier
• 金额: $ 17.16万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6815212
• 关键词: antibody; glutamate transporter; hippocampus; immunofluorescence technique; immunoprecipitation; in situ hybridization; laboratory rabbit; laboratory rat; neurons; neuroregulation; neurotransmitter transport; point mutation; protein binding; protein degradation; protein isoforms; protein localization; protein protein interaction; protein sequence; protein structure function; recombinant proteins; site directed mutagenesis; tissue /cell culture; ubiquitin; vesicle /vacuole; yeast two hybrid system

DESCRIPTION (provided by applicant): The changes in synaptic strength that underlie behavioral phenomena such as learning, memory and addiction, are usually attributed to postsynaptic changes in receptor sensitivity, but they may also reflect presynaptic regulation of the amount of transmitter released. The amount of glutamate per vesicle available for exocytotic release depends on its transport from the cytoplasm into vesicles by a family of vesicular glutamate transporter proteins, VGLUTs. VGLUT1 and 2, which account for the exocytotic release of glutamate by essentially all well-established excitatory neurons, exhibit a mutually exclusive pattern of expression in adult brain that correlates with the probability of transmitter release and the potential for plasticity. VGLUT1 also contains several protein-protein interaction domains not found in VGLUT2. The long-term goal of this K08 Mentored Clinical Scientist Development Award proposal is to understand how differences in the trafficking of VGLUT isoforms contribute to the differences in glutamate release observed at different synapses. The strategy is to study the role of C-terminal sequences in activity and trafficking of the different VGLUT isoforms. We have found that one of the polyproline motifs in the C-terminus of VGLUT1 interacts with proteins involved in synaptic vesicle recycling. We will characterize these interactions and determine whether they regulate glutamate transport by influencing vesicle filling, trafficking, or other aspects of the vesicle cycle. In addition, we will characterize and identify protein interactions with two other internalization motifs in VGLUT1. Together, these motifs may contribute to differences in the speed of vesicle filling, exocytosis and endocytosis in glutamate signaling. Increasing evidence implicates glutamate hypofunction in the pathophysiology of schizophrenia, which may involve changes in glutamate release. Thus, an understanding of the regulation of glutamate storage and release may be important in the targeting of therapeutic agents for schizophrenia

描述(申请人提供)：突触强度的变化是导致学习、记忆和成瘾等行为现象的基础，通常被归因于突触后受体敏感性的变化，但它们也可能反映了突触前对递质释放量的调节。囊泡谷氨酸转运蛋白家族VGLUT将谷氨酸从细胞质转运到囊泡中，决定了囊泡中谷氨酸的释放量。VGLUT1和VGLU2解释了几乎所有成熟的兴奋性神经元胞吐释放谷氨酸的过程，在成年脑中呈现出一种相互排斥的表达模式，这种模式与递质释放的可能性和可塑性有关。VGLUT1还包含VGLUT2中没有的几个蛋白质-蛋白质相互作用结构域。这项K08指导的临床科学家发展奖提案的长期目标是了解VGLUT亚型贩运的差异如何导致在不同突触观察到的谷氨酸释放的差异。我们的策略是研究C末端序列在不同VGLUT亚型的活性和运输中的作用。我们发现VGLUT1 C-末端的一个多聚脯氨酸基序与参与突触小泡循环的蛋白质相互作用。我们将描述这些相互作用的特征，并确定它们是否通过影响囊泡充盈、运输或囊泡周期的其他方面来调节谷氨酸的运输。此外，我们将表征和确定蛋白质与VGLUT1中另外两个内化基序的相互作用。总之，这些基序可能导致谷氨酸信号中囊泡充盈、胞吞和内吞的速度不同。越来越多的证据表明，谷氨酸功能低下与精神分裂症的病理生理有关，这可能涉及谷氨酸释放的变化。因此，了解谷氨酸的储存和释放规律对于治疗精神分裂症的药物的靶向可能是重要的。