革兰氏阴性菌膜间质蛋白酶DegP研究进展

Research progress of DegP in Gram-negative bacteria

摘要:

膜间质蛋白酶（DegP），是一种广泛存在于真核生物和原核生物细胞中的蛋白。DegP同时具有酶活性和分子伴侣活性，并通过多聚体构成胶囊状结构执行其分子伴侣功能。DegP的酶活性依赖酶切位点与PDZ1结构域双重识别方式识别底物，这种识别模式被称为"分子量尺"。在革兰氏阴性菌中，DegP主要位于膜间质，通过分子伴侣活性与酶活性帮助保护错误折叠蛋白或降解变性蛋白。DegP也参与外膜蛋白的转运，是DegP胞内活性的研究重点。DegP也可以被分泌到胞外，帮助宿主对抗恶劣环境，并参与调节生物被膜的形成。本文将从DegP的结构与活性、胞内功能与胞外功能三大方面对DegP的研究进展进行总结，为革兰氏阴性菌周质中蛋白质质量控制与DegP体外功能的进一步研究提供参考。

关键词:革兰氏阴性菌;DegP;分子伴侣;蛋白酶;蛋白质质量控制系统

Abstract:

DegP, also known as HtrA, is a protein widely distributed in eukaryotic and prokaryotic cells. It has both protease activity and chaperone activity. On one hand, DegP forms a capsule-like structure to perform its chaperone function, called "Cage assembly". On the other hand, the protease activity of DegP depends on protease active site and PDZ1 domain, called "molecular ruler". In Gram-negative bacteria periplasm, DegP protects misfolded proteins or degrades denatured proteins. For example, DegP takes part in the transport of outer membrane proteins has been well-studied to prove its functions. Additionally, DegP can be secreted to extracellular and participates in the regulation of biofilm formation. In this way, DegP endows the ability to survive from the harsh environments on bacteria. In this review we summarized the structures and functions of DegP. It provides new insights into vitro activities of DegP and how DegP works as the final step in protein quality control system.

Key words:Gram negative bacteria;DegP;molecular chaperones;protease;protein quality control system