The Functional Significance of Conformational States in Glutamatergic Signaling

谷氨酸信号传导中构象态的功能意义

基本信息

批准号：
8397675
负责人：
Catherine Lourdes Salussolia
金额：
$ 4.51万
依托单位：
STATE UNIVERSITY NEW YORK STONY BROOK
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-01-01 至 2013-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8397675
关键词：
AMPA Receptors Acute Address Adopted Adverse effects Agonist Alzheimer&apos s Disease Anabolism Biological Assay Cells Charge Chronic Clinical Coma Complex Coupling Cysteine Data Disease Drowsiness Electrophysiology (science)Electrostatics Epilepsy Exhibits Functional disorder Generations Glutamate Receptor Glutamates Goals Hallucinations Immunoblotting Ion Channel Kainic Acid Receptors Kinetics Lead Length Ligand Binding Domain Mediating Memantine Mental disorders Molecular Conformation Mood Disorders Multiple Sclerosis Mutation N-Methyl-D-Aspartate Receptors Nerve Degeneration Neuraxis Neurodegenerative Disorders Neurotransmitters Parkinson Disease Play Positioning Attribute Role Schizophrenia Signal Transduction Site-Directed Mutagenesis Stroke Structure Synaptic Transmission Techniques Therapeutic Agents Transmembrane Domain base excitotoxicity immunocytochemistry innovation insight kainate nervous system disorder neurotransmission novel novel strategies novel therapeutics patch clamp polypeptide public health relevance receptor receptor function receptor structure function research study

项目摘要

DESCRIPTION (provided by applicant): Most fast excitatory synaptic transmission in the central nervous system is mediated by the neurotransmitter glutamate. Aberrant glutamatergic neurotransmission, most notably of the NMDA receptor subtype, has been implicated in a wide variety of nervous system diseases including psychiatric disorders (e.g. schizophrenia and mood disorders), chronic neurodegenerative diseases (e.g. multiple sclerosis and Parkinson's and Alzheimer's diseases), and disorders arising from acute excitotoxicity (e.g. epilepsy and stroke). Accordingly, there is a great need for pharmacological agents that target dysfunctional glutamatergic signaling without resulting in the alteration of its normal function or the occurrence of adverse side effects (e.g. drowsiness, hallucinations, and coma). There are presently few glutamatergic-based therapies available for clinical use, but those agents that are clinically useful (amantidine and memantine) share a common theme: they modulate NMDA receptor gating (opening/closing of the ion channel) in an activity-dependent manner. Thus, understanding gating mechanisms are critical to developing novel therapeutic agents. Glutamate receptors (GluRs) are tetramers being composed of identical or similar subunits. Recently, a crystal structure of a nearly intact AMPA receptor, composed of identical subunits, showed that the receptor subunits exist in two unique conformations (termed 'A/C' and 'B/D') with subunits of the same conformation being positioned opposite one another. Functional NMDA receptors are obligate heterotetramers predominantly comprised of two GluN1 and two GluN2 subunits that adopt the 'A/C' and 'B/D' conformations respectively. In addition, native GluR subtypes (AMPA and kainate) are thought to be heterotetramers composed of at least two different subtypes. The major goal of my proposal is to study the significance of these two conformations in heteromeric AMPA and kainate receptors (Aim 1) and its significance to glutamate receptor gating (Aim 2). To address these aims, I will take advantage of specific cysteine-substituted mutations in the M3-S2 linkers, a short polypeptide that connects the ligand-binding domain to the ion channel pore, to determine a subunit's general conformation through the use of immunoblots and functional assays (patch-clamp electrophysiology). To delineate the significance of distinct conformational states in receptor function, I will alter the physical length and electrostatic composition of the M3-S2 linkers in obligate heteromultimeric NMDA receptors. Through the use of varying agonists and antagonists, the resulting data will provide insights into the gating mechanisms underlying glutamatergic signaling and allow for the innovation and generation of specific pharmacological agents aimed to treat glutamate-based diseases.