Role of small proteins and the moonlighting enzyme GapA in the degradosome-like network of Bacillus subtilis

枯草芽孢杆菌是最重要的非致病性革兰氏阳性模式生物。它天生就有能力，可以在极端条件下产生孢子，并分泌大量蛋白质。只有SR1P和SR7P这5种小蛋白得到了详细的研究。在枯草芽孢杆菌中，已经提出了一个降解体样蛋白网络（DLN），它包括rnase Y， J1/J2, PnpA，解旋酶CshA，以及作为支架成分的代谢酶烯醇化酶和PfkA。我们的团队在这个网络中首次添加了关于GapA的数据，作为进一步的支架成分和两个小蛋白，SR1P和SR7P。本应用的主要目的是研究SR1P和SR7P在特定代谢和应激条件下对枯草芽孢杆菌降解体样蛋白网络（DLN）的全局作用，并进一步阐明GapA在枯草芽孢杆菌降解体样蛋白网络中的相互作用网络和生物学作用。实验工作将分为以下几个部分，这些部分将并行进行：1)在规定的应力条件下鉴定受SR7P影响的所有RNase Y底物和受SR1P影响的所有RNase J底物(与Ulrike Mäder合作；2)研究GapA在DLN中的作用以及SR1P对枯草芽孢杆菌中gap结合的RNase Y和PnpA的潜在影响；3)绘制烯醇酶/RNase Y和SR7P/烯醇酶相互作用表面；4)研究SR1/SR1P或SR7/SR7P在同一途径中的潜在协同作用

B. subtilis is the most important non-pathogenic Gram-positive model organism. It is naturally competent, can sporulate to survive extreme conditions and secrete proteins in large quantities. Only five small proteins, among them SR1P and SR7P, have been investigated in some detail. In B. subtilis, a degradosome-like protein network (DLN) has been proposed that involves the RNases Y, J1/J2, PnpA, helicase CshA and as scaffolding components the metabolic enzymes enolase and PfkA. Our group has added to this network first data on GapA as further scaffolding component and two small proteins, SR1P and SR7P. The major aims of this application are to investigate the global role of both SR1P and SR7P on the B. subtilis degradosome-like protein network (DLN) under defined metabolic and stress conditions and to further elucidate the interaction network and biological role of GapA in the B. subtilis DLN. The experimental work will be divided into the following parts, which will be approached in parallel1) Identification of all RNase Y substrates that are affected by SR7P and all RNase J substrates that are affected by SR1P under defined stress conditions (in collaboration with Ulrike Mäder, University Greifswald) and analysis of the physiological role of the small proteins in regulatory networks involving these substrates2) Investigation of the role of GapA in the DLN and of a potential effect of SR1P on Gap-bound RNase Y and on PnpA in B. subtilis3) Mapping of the enolase/RNase Y and SR7P/enolase interaction surfaces4) Investigation of a potential concerted action of SR1/SR1P or SR7/SR7P in the sam pathway