Several membrane-anchored signal mediators such as cytokines (e.g. TNFα) and growth factors are proteolytically shed from the cell surface by the metalloproteinase ADAM17, which, thus, has an essential role in inflammatory and developmental processes. The membrane proteins iRhom1 and iRhom2 are instrumental for the transport of ADAM17 to the cell surface and its regulation. However, the structure–function determinants of the iRhom–ADAM17 complex are poorly understood. We used AI-based modelling to gain insights into the structure–function relationship of this complex. We identified different regions in the iRhom homology domain (IRHD) that are differentially responsible for iRhom functions. We have supported the validity of the predicted structure–function determinants with several in vitro, ex vivo and in vivo approaches and demonstrated the regulatory role of the IRHD for iRhom–ADAM17 complex cohesion and forward trafficking. Overall, we provide mechanistic insights into the iRhom–ADAM17-mediated shedding event, which is at the centre of several important cytokine and growth factor pathways.

一些膜锚定信号介质，如细胞因子（例如 TNFα）和生长因子，通过金属蛋白酶 ADAM17 蛋白水解从细胞表面脱落，因此在炎症和发育过程中具有重要作用。膜蛋白 iRhom1 和 iRhom2 有助于将 ADAM17 转运至细胞表面并进行调节。然而，人们对 iRhom-ADAM17 复合体的结构-功能决定因素知之甚少。我们使用基于人工智能的建模来深入了解这种复合体的结构-功能关系。我们确定了 iRhom 同源域 (IRHD) 中的不同区域，这些区域对 iRhom 功能有不同的影响。我们已经支持了预测的结构-功能决定因素的有效性，有几个体外，离体和体内方法并证明了 IRHD 对 iRhom-ADAM17 复合物凝聚和前向运输的调节作用。总的来说，我们提供了对 iRhom–ADAM17 介导的脱落事件的机制见解，这是几个重要的细胞因子和生长因子途径的中心。