1. Identification and function of an Arasin-like peptide from Litopenaeus vannamei
- Author
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Yuanmao Yao, Shuang Zhang, Wei Xiao, Chaozheng Li, Cuihong Hou, Lili Shi, and Bang Xiao
- Subjects
Signal peptide ,Gills ,Staphylococcus aureus ,Hemocytes ,Immunology ,Antimicrobial peptides ,Litopenaeus ,Peptide ,Microbiology ,Arthropod Proteins ,Penaeidae ,Animals ,Cloning, Molecular ,chemistry.chemical_classification ,biology ,Vibrio parahaemolyticus ,Staphylococcal Infections ,biology.organism_classification ,Immunity, Innate ,Shrimp ,Open reading frame ,Poly I-C ,chemistry ,Virus Diseases ,Vibrio Infections ,Heterologous expression ,Antimicrobial Peptides ,Developmental Biology ,Antimicrobial Cationic Peptides - Abstract
Antimicrobial peptides (AMPs) play an important role in the host defense system of shrimps. In this study, an Arasin-like peptide, named as LvArasin-like, was identified from the hemocytes of the pacific white shrimp, Litopenaeus vannamei. The complete open reading frame (ORF) of LvArasin-like was 213 bp, encoding 70 amino acid residues with a predicted molecular mass of 5.68 kDa and a theoretical isoelectric point (pI) of 6.73. The predicted peptide consisted of a signal peptide, an N-terminal Pro/Arg-rich domain, and a C-terminal cysteine-rich domain. LvArasin-like expression was most abundant in the gills and was up-regulated in hemocytes after LPS or Poly I:C injection as well as challenges by Vibrio parahaemolyticus or Staphylococcus aureus infection. In the heterologous expression system, LvArasin-like protein (rLvArasin-like) was recombinantly expressed in the forms of a dimer or both a monomer and dimer. The rLvArasin-like could directly bind to gram-positive and gram-negative bacteria and exhibited broad-spectrum antimicrobial activity towards them, with 50 % of minimal inhibitory concentrations (MIC50) of 6.25–50 μM. Moreover, dsRNA-mediated knockdown of LvArasin-like enhanced the susceptibility of shrimp to V. parahaemolyticus. In addition, the transcriptional level of LvArasin-like was downregulated when silencing of the transcription factors LvDorsal and LvRelish using RNAi in vivo. All of these results suggest that LvArasin-like is involved in host defense against bacterial infection. Therefore, it is a potential therapeutic agent for disease control in shrimp aquaculture.
- Published
- 2021