A trypsin-like serine protease domain of masquerade gene in crayfish Procambarus clarkii could activate prophenoloxidase and inhibit bacterial growth. (April 2021)

• Record Type: Journal Article
• Authors: Yang, Hui; Ji, Tongwei; Xiong, Haoran; Zhang, Yingying; Wei, Wenzhi
• Is Part Of: Developmental and comparative immunology. Volume 117(2021)
• Publication Date: 2021-04
• Subjects: Procambarus clarkii -- Masquerade -- Trypsin-like serine protease -- Prophenoloxidase -- Antibacterial activity; Immunology -- Periodicals; Developmental immunology -- Periodicals; 616.079
• DOI: 10.1016/j.dci.2020.103980
• Languages: English
• ISSNs: 0145-305X

Abstract

Abstract: Masquerade (Mas) is a secreted trypsin-like serine protease (SPs) and involved in immune response in some arthropods. However, according to previous studies, Mas presents different functional activities. In the present study, the functional mechanisms of Mas in crayfish Procambarus clarkii immune defense were studied. A fragment cDNA sequence of Pc Mas was identified and characterized. From the structural analysis, it contains a trypsin-like serine protease domain. The highest expression level of Pc Mas was detected in hepatopancreas. The infection of A. hydrophila could induce the expression of Pc Mas, while the WSSV infection did not cause changes in the expression of PcMas . Through the prokaryotic expression system, the Pc Mas protein was expressed in E. coli . It was verified that Pc Mas can bind to bacteria in vitro and inhibit the growth of the bacteria. By dsRNA interference with the expression of Pc Mas, the decrease expression of Pc Mas led to a decrease in the activity of phenoloxidase in hemolymph and an increase of mortality caused by A. hydrophila infection. The injection of recombinant protein can enhance the activity of phenoloxidase and reduce mortality caused by A. hydrophila infections. Therefore, the present study confirmed that Pc Mas could improve the body's immune response to eliminate bacterial pathogens by binding with bacteria and activating the prophenoloxidase system. The results will enrich the molecular mechanisms of crustaceans immune defense. Highlights: A trypsin-like serine protease domain of masquerade gene was characterized from Procambarus clarkii. The infection of A. hydrophila could induce the up-regulation of Pc Mas in hepatopancreas. The recombinantly Pc Mas protein could bind to bacteria in vitro and inhibit the growth of the bacteria. The silenced Pc Mas gene could increase the mortality after A. hydrophila infections. The r Pc Mas protein enhance hemolymph phenoloxidase activities and reduce mortality.