Teamwork of DEG Proteases in Protein Degradation on Both Sides of the Thylakoid Membrane

在进行含氧光合作用并产生大量活性氧作为副产物的生物体中，蛋白质质量控制尤其重要，因为活性氧可能导致蛋白质氧化损伤。暴露于光下的绿色植物组织光氧化损伤的主要目标是叶绿体及其光合机构。我们在过去的研究中证明，来自光系统II反应中心的光损伤D1蛋白是由位于类囊体膜基质和管腔侧的丝氨酸DEG蛋白酶协同切割的。我们打算通过位于类囊体膜两侧的DEG蛋白酶的联合作用来研究光损伤的光合蛋白的降解。在共同努力下，我们计划寻找个体（基质和类囊体腔蛋白）和共享（终端在膜两侧的类囊体膜蛋白）DEG降解物（一组底物），并研究翻译后修饰在底物和DEG蛋白酶水平上的蛋白水解活性调节中的作用。

The protein quality control is especially important in organisms that perform oxygenic photosynthesis and generate large amounts of reactive oxygen species as byproducts that might lead to oxidative damage of proteins. The main target of photooxidative damage in green plant tissues exposed to light is the chloroplast and its photosynthetic apparatus. We demonstrated in the past that photodamaged D1 protein from photosystem II reaction center is cleaved by teamwork of serine DEG proteases located at stromal and lumenal sides of the thylakoid membrane. We intend to study the degradation of photodamaged photosynthetic proteins by a combined action of DEG proteases located at both sides of the thylakoid membrane. In a joint effort we plan to search for individual (stroma and thylakoid lumen proteins) and shared (thylakoid membrane proteins with termini at both membrane sides) DEG degradomes (a set of substrates) and investigate the role of post-translational modifications in the regulation of proteolytic activity at substrate and DEG protease levels.