Maturation of subtilisin-like protease NbSLP1 from microsporidia .
Rong Wang, Qingyan Li, Fangyan Liu, Xiaoqun Dang, Quan Sun, Xiaotian Sheng, Mingyu Hu, Jialing Bao, Jie Chen, Guoqing Pan, Zeyang Zhou
Author Information
Rong Wang: State Key Laboratory of Silkworm Genome Biology, Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China.
Qingyan Li: State Key Laboratory of Silkworm Genome Biology, Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China.
Fangyan Liu: State Key Laboratory of Silkworm Genome Biology, Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China.
Xiaoqun Dang: College of Life Sciences, Chongqing Normal University, Chongqing, China.
Quan Sun: State Key Laboratory of Silkworm Genome Biology, Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China.
Xiaotian Sheng: State Key Laboratory of Silkworm Genome Biology, Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China.
Mingyu Hu: State Key Laboratory of Silkworm Genome Biology, Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China.
Jialing Bao: State Key Laboratory of Silkworm Genome Biology, Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China.
Jie Chen: State Key Laboratory of Silkworm Genome Biology, Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China.
Guoqing Pan: State Key Laboratory of Silkworm Genome Biology, Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China.
Zeyang Zhou: State Key Laboratory of Silkworm Genome Biology, Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China.
Microsporidia are obligate intracellular parasites and possess a unique way of invading hosts, namely germination. Microsporidia are able to infect almost all animal cells by germination. During the process, the polar tube extrudes from the spores within, thus injecting infectious sporoplasm into the host cells. Previous studies indicated that subtilisin-like protease 1 (NbSLP1) of microsporidia were located at the polar cap of germinated spores where the polar tube extrusion. We hypothesized that NbSLP1 is an essential player in the germination process. Normally, SLP need to be activated by autoproteolysis under conditions. In this study, we found that the signal peptide of NbSLP1 affected the activation of protease, two self-cleavage sites were involved in NbSLP1 maturation between AlaAsp and AlaAsp respectively. Mutants at catalytic triad of NbSLP1 confirmed the decreasing of autoproteolysis. This study demonstrates that intramolecular proteolysis is required for NbSLP1 maturation. The protease undergoes a series of sequential N-terminal cleavage events to generate the mature enzyme. Like other subtilisin-like enzymes, catalytic triad of NbSLP1 are significant for the self-activation of NbSLP1. In conclusion, clarifying the maturation of NbSLP1 will be valuable for understanding the polar tube ejection mechanism of germination.
