A fibrinogen-related protein (FREP) is involved in the antibacterial immunity of Marsupenaeus japonicus.
Fibrinogen-related proteins (FREPs) in invertebrates have important functions in innate immunity. In this study, the cDNA of FREP was identified from the kuruma shrimp Marsupenaeus japonicus (MjFREP2). The full-length cDNA of MjFREP2 is 1138 bp with an open reading frame of 954 bp that encodes a 317-amino acid protein comprising a signal peptide and a fibrinogen-like domain. MjFREP2 could be detected in hemocytes, heart, hepatopancreas, gills, stomach, and intestines. MjFREP2 could also be upregulated in hemocytes after Vibrio anguillarum and Staphylococcus aureus challenge. Agglutination and binding assay results revealed that the recombinant MjFREP2 bound to bacteria and polysaccharides. Immunocytochemical analysis results showed that MjFREP2 proteins were mainly distributed in the cytoplasm of hemocytes from unchallenged shrimp and transported to the membrane or secreted out of the cell after V. anguillarum or S. aureus challenge. The secreted MjFREP2 bound to the bacteria presented in shrimp hemolymph. The overexpression of MjFREP2 could enhance bacterial clearance by inducing the phagocytosis of hemocytes. This ability was impaired by knockdown of MjFREP2 with RNA interference. The cumulative mortality of MjFREP2-silenced shrimp was significantly higher than that of the control shrimp. These results suggested that MjFREP2 has an important function in the antibacterial immunity of M. japonicus.
MOE Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China.
Jie-Jie
JJ
Sun
MOE Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China.
Jiang-Feng
JF
Lan
MOE Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China.
Xiu-Zhen
XZ
Shi
MOE Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China.
Ming-Chong
MC
Yang
MOE Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China.
Hui-Ting
HT
Yang
MOE Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China.
Xiao-Fan
XF
Zhao
MOE Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China. Electronic address: jxwang@sdu.edu.cn.
Jin-Xing
JX
Wang
D000818:Animals; D019295:Computational Biology; D017931:DNA Primers; D018076:DNA, Complementary / Q000235:genetics; D005340:Fibrinogen / Q000276:immunology*; D005786:Gene Expression Regulation / Q000276:immunology*; D006434:Hemocytes / Q000276:immunology; D007136:Immunoglobulins / Q000235:genetics / Q000276:immunology*; D016366:Open Reading Frames / Q000235:genetics; D033561:Penaeidae / Q000276:immunology* / Q000382:microbiology*; D010587:Phagocytosis / Q000276:immunology; D017434:Protein Structure, Tertiary; D034622:RNA Interference; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013211:Staphylococcus aureus / Q000276:immunology*; D014733:Vibrio / Q000276:immunology*
D017931:DNA Primers; D018076:DNA, Complementary; D007136:Immunoglobulins; D005340:Fibrinogen
Fibrinogen-related protein; Innate immunity; Pattern recognition receptor; Phagocytosis