Interfering with protein interaction of phosphoinositide-3-kinase gamma and of store-operated calcium channels

可溶性或内膜结合蛋白与质膜蛋白的受调节的相互作用是免疫细胞中由外向内和由内向外信号传导中的常见现象，并且有助于炎症和过敏的病理生理状态。通过与G β y和Ras的活性形式对接，磷酸肌醇3-激酶y由作用于G蛋白偶联受体的趋化因子和负载IgE的Fes受体的抗原识别控制，从而触发定向迁移、氧化爆发或脱粒反应。磷酸肌醇3-激酶y的p101和p87衔接蛋白上的蛋白质-蛋白质相互作用界面是这种信号传导所需的，已经揭示了意想不到的特性，并进行了更详细的表征，并进行了小分子置换筛选。与PISKy激活同时，磷脂酶C介导的[Ca 2 +]i信号传导被触发，其延迟和持久的组分或持续的振荡活性严重依赖于以由内而外的方式起作用的Ca 2+储存再填充机制。内质网Ca 2+传感器蛋白STIM 1与质膜Ca 2+通道Orai 1的可逆结合为Ca 2+释放激活的Ca 2+内流（ICRAC）提供了分子机器，以补充Ca 2+储存并维持Ca 2+信号网络处于响应状态。使用稳定转染的细胞系和小分子筛选，我们正在靶向这一途径。此外，我们已经确定了一组Orai 1相互作用的蛋白质，ORIP 1和ORIP 2，其功能是迄今为止未知的。这些复合物可能代表通过药理学干扰调节免疫应答的额外靶点。

The regulated interaction of soluble or endomembrane-bound proteins with plasma membrane proteins is a common phenomenon in outside-in and inside-out signalling in immune cells and contributes to pathophysiological states in inflammation and allergy. By docking to the active forms of Gßy and Ras, phosphoinositide 3-kinase y is controlled by chemokines acting on G-protein-coupled receptors and by antigen recognition by IgE-loaded Fes receptors, triggering directional migration, oxidative burst or degranulation responses. Protein-protein interaction interfaces on the p101 and p87 adapter proteins of phosphoinositide 3-kinase y that are required for this signalling have revealed unanticipated properties and are characterized in more detail and subjected to displacement screening with small molecules. Coincident with PISKy activation, phospholipase C-mediated [Ca2+]i signalling is triggered, whose delayed and longlasting component or ongoing oscillatory activity critically depends on a Ca2+ store refilling mechanism acting in an inside-out manner. The reversible association of STIM1, an endoplasmic reticulum Ca2+ sensor protein, with Orai1, a plasma membrane-located Ca2+-channel provide a molecular machine for Ca2+ releaseactivated Ca2+ influx (ICRAC) to refill Ca2+ stores and to maintain the Ca2+ signalling network in a responsive state. Using stably transfected cell lines and small molecule screening, we are targeting this pathway. In addition, we have identified a group of Orai1-interacting proteins, ORIP1 and ORIP2, whose functions are so far unknown. These complexes may represent additional targets for modulation of immunological responses by pharmacological interference.