Peptide Receptor Systems

肽受体系统

• 批准号: 7136259
• 负责人: Ted B Usdin
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF MENTAL HEALTH
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7136259
• 关键词: animal tissue; genetic library; hormone receptor; laboratory rat; neuropeptide receptor; neuropeptides; neurotransmitter receptor; pain threshold; parathyroid hormones; protein structure function; zebrafish

Neurotransmitter receptors provide access to neuronal circuits for investigation of their biology, and potentially for therapeutic intervention. Peptides have effects on G-protein coupled receptors that are often relatively long lasting and they may have a modulatory role. These subtle effects may be relevant to the basis or treatment of mental illness. We are studying a family of G-protein coupled receptors (referred to as the secretin-VIP, B, or type II family) that is structurally distinct from the majority of G-protein coupled receptors (rhodopsin- or beta-adrenergic-like). Recently we have focused on the parathyroid hormone 2 (PTH2) receptor, which we identified in a screen for novel central nervous system expressed polypeptide receptors. Our initial studies of the human PTH2 receptor showed that it was activated by parathyroid hormone (PTH). Mapping the PTH2 receptor's anatomical distribution revealed expression within brain areas not normally exposed to circulating peptides, such as PTH. Furthermore, we found that PTH poorly activates the rat PTH2 receptor. Using selective activation of the PTH2 receptor as an assay we purified a previously unknown 39 amino acid peptide from bovine hypothalamus. This peptide, which we named tuberoinfundibular peptide of 39 residues (TIP39), activates PTH2 receptors from human, rat and zebrafish and does not activate PTH1 receptors. Both rat and zebrafish PTH2 receptors are much more effectively activated by TIP39 than PTH, supporting the suggestion that a TIP39 homologue is their natural ligand. Mapping the neuroanatomical distribution of TIP39 synthesizing neurons and their projections has generated hypotheses about the physiological function of TIP39. We have found that PTH2-R synthesizing neurons use glutamate as a neurotransmitter. We are testing hypotheses for the biological role (s) of TIP39 and the PTH2 receptor derived from detailed mapping of the receptor and peptides distributions. Together with the predominant localization of the PTH2R in nerve terminals this suggests that TIP39 modulates excitatory neurotransmission in specific circuits. We have obtained data that supports a role for TIP39 and the PTH2 receptor in modulating pain perception and shown that it has similar effects to antidepressant and anxiolytic drugs in some animal behavior assays. We, and other investigators, also have preliminary data supporting a role for TIP39 and the PTH2 receptor in pituitary hormone release. We are attempting to develop mice with PTH2 receptor and TIP39 null phenotypes to aid in elucidating the function of this peptide-receptor system. We have implemented a method for generation of high quality full-length enriched cDNA libraries from small amounts of starting material that should facilitate identification of the sequences of gene products that are expressed with highly circumscribed tissue distributions.

神经递质受体提供了进入神经元回路的途径，以研究其生物学，并可能用于治疗干预。肽对 G 蛋白偶联受体的影响通常相对较长，并且可能具有调节作用。这些微妙的影响可能与精神疾病的基础或治疗有关。我们正在研究一个 G 蛋白偶联受体家族（称为促胰液素-VIP、B 或 II 型家族），其结构与大多数 G 蛋白偶联受体（视紫红质或 β 肾上腺素样受体）不同。最近，我们重点关注甲状旁腺激素 2 (PTH2) 受体，我们在筛选新型中枢神经系统表达的多肽受体时发现了该受体。我们对人类 PTH2 受体的初步研究表明，它是由甲状旁腺激素 (PTH) 激活的。绘制 PTH2 受体的解剖分布图揭示了通常不接触循环肽（例如 PTH）的大脑区域内的表达。此外，我们发现 PTH 很难激活大鼠 PTH2 受体。通过选择性激活 PTH2 受体作为检测方法，我们从牛下丘脑中纯化了一种以前未知的 39 个氨基酸肽。这种肽被我们命名为 39 个残基的结节漏斗肽 (TIP39)，可激活人类、大鼠和斑马鱼的 PTH2 受体，但不会激活 PTH1 受体。 TIP39 比 PTH 更有效地激活大鼠和斑马鱼 PTH2 受体，这支持了 TIP39 同源物是它们天然配体的建议。绘制 TIP39 合成神经元的神经解剖学分布及其预测已经产生了关于 TIP39 生理功能的假设。我们发现PTH2-R合成神经元使用谷氨酸作为神经递质。我们正在测试根据受体和肽分布的详细图谱得出的 TIP39 和 PTH2 受体生物学作用的假设。结合 PTH2R 在神经末梢的主要定位，这表明 TIP39 调节特定回路中的兴奋性神经传递。我们获得的数据支持 TIP39 和 PTH2 受体在调节疼痛感知中的作用，并表明在一些动物行为测定中它与抗抑郁药和抗焦虑药物具有相似的作用。我们和其他研究人员也有初步数据支持 TIP39 和 PTH2 受体在垂体激素释放中的作用。我们正在尝试培育具有 PTH2 受体和 TIP39 缺失表型的小鼠，以帮助阐明该肽受体系统的功能。 我们已经实施了一种从少量起始材料生成高质量全长富集 cDNA 文库的方法，该方法应有助于鉴定以高度限制的组织分布表达的基因产物的序列。