A shrimp pacifastin light chain-like inhibitor: Molecular identification and role in the control of the prophenoloxidase system. Issue 1 (January 2016)

• Record Type: Journal Article
• Authors: Sangsuriya, Pakkakul; Charoensapsri, Walaiporn; Chomwong, Sudarat; Senapin, Saengchan; Tassanakajon, Anchalee; Amparyup, Piti
• Is Part Of: Developmental and comparative immunology. Volume 54:Issue 1(2016)
• Page Start: 32
• Page End: 45
• Publication Date: 2016-01
• Subjects: Shrimp immunity -- Penaeus monodon -- Serine proteinase inhibitor -- Melanization -- Prophenoloxidase -- Pacifastin -- Kunitz; Immunology -- Periodicals; Developmental immunology -- Periodicals; 616.079
• DOI: 10.1016/j.dci.2015.08.003
• Languages: English
• ISSNs: 0145-305X

Abstract

Abstract: Pacifastin is a recently classified family of serine proteinase inhibitors that play essential roles in various biological processes, including in the regulation of the melanization cascade. Here, a novel pacifastin-related gene, termed Pm Pacifastin-like, was identified from a reverse suppression subtractive hybridization (SSH) cDNA library created from hemocytes of the prophenoloxidase Pm proPO1/2 co-silenced black tiger shrimp Penaeus monodon . The full-length sequences of Pm Pacifastin-like and its homologue Lv Pacifastin-like from the Pacific white shrimp Litopenaeus vannamei were determined. Sequence analysis revealed that both sequences contained thirteen conserved pacifastin light chain domains (PLDs), followed by two putative kunitz domains. Expression analysis demonstrated that the Pm Pacifastin-like transcript was expressed in all tested shrimp tissues and larval developmental stages, and its expression responded to Vibrio harveyi challenge. To gain insight into the functional roles of Pm Pacifastin-like protein, the in vivo RNA interference experiment was employed; the results showed that Pm Pacifastin-like depletion strongly increased PO activity. Interestingly, suppression of Pm Pacifastin-like also down-regulated the expression of the proPO-activating enzyme Pm PPAE2 transcript; the Pm Pacifastin-like transcript was down-regulated after the Pm proPO1/2 transcripts were silenced. Taken together, these results suggest that Pm Pacifastin-like is important in the shrimp proPO system and may play an essential role in shrimp immune defense against bacterial infection. These results also expand the knowledge of how pacifastin-related protein participates in the negative regulation of the proPO system in shrimp. Highlights: Pm Pacifastin-like gene was identified from a SSH library of Pm proPO1/2 knockdown shrimp. Pm Pacifastin-like protein contains both pacifastin light chain- and kunitz-domains. Suppression of Pm Pacifastin-like gene significantly increased shrimp PO activity. Pm Pacifastin-like gene implicates in the negative regulation of the shrimp proPO system.