Biotechnology Bulletin ›› 2022, Vol. 38 ›› Issue (5): 149-158.doi: 10.13560/j.cnki.biotech.bull.1985.2021-1067

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Function Analysis of Lon1 Protease Involved in High Temperature Stress and Cell Division of Deinococcus radiodurans R1

ZHAO Ming-ming1(), TANG Yin1, GUO Lei-zhou1, HAN Jia-hui1, GE Jia-ming1, MENG Yong2, PING Shu-zhen1, ZHOU Zheng-fu1, WANG Jin1()   

  1. 1. Biotechnology Research Institute,Chinese Academy of Agricultural Sciences,Beijing 100081
    2. Mianyang Habio Bioengineering Co.,Ltd,Mianyang 621011
  • Received:2021-08-09 Online:2022-05-26 Published:2022-06-10
  • Contact: WANG Jin E-mail:82101182064@caas.cn;wangjin@caas.cn

Abstract:

Lon is a type of proteases that widely present in many organisms. It prevents cell damage that is caused by irreversible protein aggregation through hydrolyzing damaged and useless proteins,and plays an important role in promoting the turnover and reuse of intracellular amino acids. The supper resistance of the extremophilic microorganisms Deinococcus radiodurans R1 to abiotic stress is closely related to its powerful intracellular protein homeostasis system. However,as an important part of the proteolytic system,little is known about the role of Lon in D. radiodurans R1. Therefore,this study chosen the Lon1 of D. radiodurans as the research object to analyze its function under abiotic stress. The results showed that the transcription of lon1 was induced by high temperature. Proteomics analysis of 48℃ showed that deletion of lon1 significantly up-regulated the expression levels of several molecular chaperones,and several proteins involved in membrane function and transport,DNA repair,transcriptional regulation and energy metabolism;and deletion of lon1 down-regulated the expression levels of 5 cell morphogenesis-related proteins. Electron microscopy results confirmed that the deletion of lon1 resulted in the abnormal cell division,the formation of giant cells,and the severe damages of the cell membrane. In addition,abiotic stress experiments uncovered the deletion of lon1 made D. radiodurans sensitive to 0.2 mol/L NaCl and 48℃ high temperature. Therefore,it is speculated that Lon1 is mainly involved in the cell morphogenesis of D. radiodurans and plays a role in adapting to high temperature and other abiotic stresses.

Key words: Deinococcus radiodurans R1, Lon, abiotic stress, proteomics