Characterization of a New Class of Receptors: Identifying ligands for the membrane receptors of the class IIIa human adenylate cyclases.

一类新受体的表征：鉴定 IIIa 类人腺苷酸环化酶膜受体的配体。

• 批准号: 456822801
• 负责人: Professor Dr. Joachim E. Schultz
• 金额: --
• 依托单位: Pharmazeutisches Institut
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/456822801?language=en
• 关键词: Characterization; New; Class; Receptors; Identifying

The membrane anchors of the nine adenylate cyclases in mammals possess a total of 12 alpha-helical transmembrane spans (2 x 6TM). These membrane anchors are evolutionarily conserved for more than half a billion years. Since 1989 discussions took place speculating about a physiological function of the membrane anchors beyond membrane anchoring. For three decades this laboratory has carried out studies in order to assign a physiological role to the membrane anchors, We used the quorum-sensing receptors from Vibrio harveyi and Legionella pneumophila. These receptors are hexahelical in the monomeric proteins which dimerize, i.e. they are almost isosteric to the membrane anchors of the mammalian adenylate cyclases. In addition, lipophilic ligands are known for these quorum-sensing receptors. In chimeras comprising various class III adenylate cyclases and quorum.sensing receptors we demonstrated in 2020 beyond a reasonable doubt that the membrane anchor of mammalian adenylate cyclases can operate as ligand receptors which attenuate the Gsalpha activation of mammalian adenylate cyclases. Currently, the chemical identity of the ligands is unknown. We identified biochemically "ligandactivity" in serum from fish, chicken, cow, and humans, among others. Enrichment of ligands by various purification methods identified acidic lipohilic compounds as ligands. A first lipidomic analysis yielded data which are hints to identify the chemical nature of the ligands in the foreseeable future. This is the first aim of the proposal. Then we wish to characterize biochemically and pharmacologically ligand-receptor interactions for all nine human adenylate cyclase isoforms. We will attempt to identify potential agonists and antagonist based on our knowledge of the chemical identity of peculiar ligands. Adenylatcyclases are known to be regulated by several cytosolic secondary modifications. We will investigate how ligand-receptor controlled regulation and regulation by secondary modifications are interacting. Finally, we will examine the regulation of intracellular cAMP levels in HEK293 cells in order to gain initial indications for physiological actions of adenylate cyclase receptor ligands.

哺乳动物9种腺苷酸环化酶的膜锚定共有12个α-螺旋跨膜跨膜(2x6TM)。这些膜锚在进化上被保存了超过5亿年。自1989年以来，人们一直在讨论膜锚在膜锚外的生理功能。三十年来，这个实验室一直在进行研究，以分配膜锚的生理作用，我们使用了来自哈维氏弧菌和嗜肺军团菌的群体感应受体。这些受体在二聚化的单体蛋白中是六螺旋的，即它们与哺乳动物腺苷环化酶的膜锚几乎是等空间的。此外，亲脂配体是已知的这些群体感应受体。在由多种三型腺苷酸环化酶和仲裁感应受体组成的嵌合体中，我们在2020年证明了哺乳动物腺苷环化酶的膜锚可以作为配体受体发挥作用，从而减弱哺乳动物腺苷环化酶的Gsalpha激活。目前，这些配体的化学特性尚不清楚。我们从鱼、鸡、牛和人类等人的血清中鉴定出了生化“配体活性”。通过各种纯化方法对配体的浓缩，确定了酸性亲脂化合物为配体。第一个脂肪组学分析产生了数据，这些数据提示在可预见的未来确定配体的化学性质。这是该提案的第一个目标。然后，我们希望从生化和药理学的角度描述所有9种人类腺苷环化酶亚型的配体-受体相互作用。我们将尝试根据我们对特殊配体的化学特性的知识来识别潜在的激动剂和拮抗剂。已知腺化环化酶受几种胞质次级修饰的调节。我们将研究配体-受体控制的调控和二次修饰调控是如何相互作用的。最后，我们将研究HEK293细胞内cAMP水平的调节，以获得腺苷环化酶受体配体的生理作用的初步迹象。