Three different anti-lipopolysaccharide factors identified from giant freshwater prawn, Macrobrachium rosenbergii.
Anti-lipopolysaccharide factor (ALF) is a type of basic protein and an important antimicrobial peptide that can bind and neutralize lipopolysaccharides (LPS). This protein shows a broad spectrum of antimicrobial activity. In this study, three forms of ALF designated as MrALF5, MrALF6, and MrALF7 were identified from giant freshwater prawn, Macrobrachium rosenbergii. MrALF5, MrALF6, and MrALF7 genes encode 133, 121, and 120 amino acids of the corresponding proteins, respectively. All these ALF proteins contain LPS-binding domain with two conserved cysteine residues. The genomic sequences of MrALF5 and MrALF7 were amplified. The genomic structures of MrALF5 and MrALF7 comprise three exons interrupted by two introns. Phylogenetic analysis showed that MrALF5, MrALF6, and MrALF7 were clustered into clade II. Evolutionary analysis showed that ALF genes from M. rosenbergii may suffer a rapid evolution. MrALF5 was expressed mainly in the hepatopancreas, gills, and heart. MrALF6 was mainly distributed in the intestine and hepatopancreas. The highest expression level of MrALF7 was detected in the hepatopancreas. MrALF6, as well as MrALF7, was downregulated by Escherichia coli challenge, and all three ALF genes were upregulated by Vibrio or white spot syndrome virus challenge. MrALF6 was also upregulated by Staphylococcus aureus challenge. In summary, the three isoforms of ALF genes may participate in the innate immune response against bacteria and virus infecting the giant fresh water prawn.
Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, PR China. renqian0402@126.com
Qian
Q
Ren
Zhao
Z
Zhang
Xin-Chang
XC
Li
Jie-Du
Kai-Min
KM
Hui
Chi-Yu
CY
Zhang
Wen
W
Wang
D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000235:genetics* / Q000276:immunology*; D060829:Arthropod Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D001483:Base Sequence; D018076:DNA, Complementary / Q000235:genetics; D020869:Gene Expression Profiling / Q000662:veterinary; D005786:Gene Expression Regulation; D008969:Molecular Sequence Data; D033541:Palaemonidae / Q000235:genetics* / Q000276:immunology*; D010802:Phylogeny; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D016415:Sequence Alignment / Q000662:veterinary
D023181:Antimicrobial Cationic Peptides; D060829:Arthropod Proteins; D018076:DNA, Complementary; D020033:Protein Isoforms