Mechanisms and Regulation of Rhomboid Intramembrane Proteolysis

在进化过程中，物种通过基因复制和基因修饰获得新的基因。显然，在细菌、古生菌、真菌、植物和动物等生命王国之间存在着实质性的进化差异。尽管存在这些多样性，但值得注意的是，在整个进化过程中，一些蛋白质在所有王国中都是保守的，并且可以在哺乳动物以及常见的细菌大肠杆菌中找到。蛋白质的这种保守性意味着它们具有基本的功能，也就是说，它们是确保生物体在所有类型的生命中正常运作所必需的。***这些保守的蛋白质包括我们正在研究的菱形蛋白酶。菱形蛋白酶结合在细胞膜上，控制信号分子的释放，而信号分子通常是细胞间通讯所必需的。细菌菱形蛋白酶研究得很好，我们甚至知道细菌菱形蛋白的确切结构。但是，尽管它们在动物中得到了保护，但只有少数出版物描述了它们在哺乳动物中潜在功能的初步研究。我们希望进一步了解哺乳动物菱形蛋白酶，因为我们确信它们在哺乳动物中具有重要的生物学功能。为了实现我们的目标，我们进行了三个研究项目：***1)为了揭示菱形蛋白酶的功能，了解蛋白酶处理的底物是有帮助的。我们最近发现了一种菱形蛋白酶的新底物，菱形样-4。有了这种新的底物，我们将能够研究酶是如何识别底物的，以及菱形酶的活性是如何调节的。***2) rhomboid -4及其新底物均存在于肾脏和肺部。我们假设菱形样4控制细胞表面底物的水平，从而影响肾脏和/或肺的细胞间通讯。我们将进一步研究这种菱形蛋白酶在细胞内与哪些蛋白质相互作用。***3)我们的第三个项目研究菱形蛋白酶-1，这是一种知之甚少的菱形蛋白酶。我们是第一个实验分析这种菱形蛋白酶的研究小组：我们确定菱形样-1发生在神经元中，我们正在研究这种基因缺失的小鼠模型，这将告诉我们它的生理功能。****综上所述，我实验室的学员正在进行基础生化研究，从最初的步骤开始调查哺乳动物系统中这一非凡的酶家族，并阐明它们的生理功能

During evolution, species acquired new genes through gene duplication as well as through modifications. Obviously, there are substantial evolutionary differences between kingdoms of life such as bacteria, archaea, fungi, plantae and animals. Despite these diversities, it is remarkable that some proteins were conserved in all kingdoms throughout evolution and can be found in mammals as well as in the common bacteria Escherichia coli. Such conservation of proteins implies that they carry fundamental functions, i.e., they are required to ensure normal functioning of the organism throughout all types of life. ***Such conserved proteins comprises the rhomboid proteases, which we are investigating. Rhomboid proteases are bound in cell membranes and control the release of signaling molecules, which are often essential for the communication between cells. The bacterial rhomboid proteases are well studied and we even know the exact structure of bacterial rhomboid proteins. But despite their conservation up to animals, there are only a few publications describing first studies of their potential functions in mammals. We want to advance the knowledge on mammalian rhomboid proteases since we are convinced that they carry essential biological functions in mammals. To achieve our aims, we follow three research projects:***1) To unravel the function of a rhomboid protease, it is helpful to know the substrate that is processed by the protease. We have recently identified a novel substrate for one rhomboid protease, rhomboid-like-4. With this novel substrate, we will be able to investigate how the enzyme recognizes the substrate and how rhomboid enzymatic activity is regulated.***2) Rhomboid-like-4 and its new substrate both occur in kidney and lung. We hypothesize that rhomboid-like-4 controls the levels of substrates at the cell surface and therefore impacts on the cell-cell communication in kidney and/or lung. We will further investigate with which proteins this rhomboid protease interacts inside the cell.***3) Our third project investigates rhomboid protease-1, a rhomboid about which very little knowledge is available. We are the first research group to experimentally analyze this rhomboid protease: We determined that rhomboid-like-1 occurs in neurons and we are investigating a mouse model with a deletion in this gene, which will tell us about its physiological functions. ****In summary, the trainees in my laboratory are performing basic biochemical research from the very first steps to investigate this family of remarkable enzymes in mammalian system and to shed light on their physiological functions.**