Two short antimicrobial peptides derived from prosaposin-like proteins in the starry flounder (Platichthys stellatus)

• Published in: Fish & shellfish immunology 2020-10, Vol.105, p.95-103
• Main Authors: Choi, Kwang-Min, Hwang, Seong Don, Joo, Min-Soo, Hwang, Jee Youn, Kwon, Mun-Gyeong, Jeong, Ji-Min, Seo, Jung Soo, Lee, Ji Hoon, Lee, Hee-Chung, Park, Chan-Il
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Antimicrobial peptide; Biofilm; DNA; Fish Diseases - immunology; Fish Proteins - chemistry; Fish Proteins - genetics; Fish Proteins - immunology; Flounder - genetics; Flounder - immunology; Gene Expression Profiling - veterinary; Gene Expression Regulation - immunology; Immunity, Innate - genetics; Miamiensis avidus; Novirhabdovirus - physiology; Phylogeny; Platichthys stellatus; Pore Forming Cytotoxic Proteins - chemistry; Pore Forming Cytotoxic Proteins - genetics; Pore Forming Cytotoxic Proteins - immunology; Prosaposin-like protein; Rhabdoviridae Infections - immunology; Rhabdoviridae Infections - veterinary; Saposins - chemistry; Saposins - genetics; Saposins - immunology; Sequence Alignment - veterinary; Starry flounder; Streptococcal Infections - immunology; Streptococcal Infections - veterinary; Streptococcus - physiology; Streptococcus iniae; Streptococcus parauberis; Vibrio campbellii
• ISSN: 1050-4648; 1095-9947
• DOI: 10.1016/j.fsi.2020.05.075

Prosaposin (PSAP) is a precursor of saposin (SAP), which is present in lysosomal and secreted proteins. PSAP is a member of the SAP-like protein families, which comprise multifunctional proteins. In particular, their antimicrobial activity has been reported. We identified PSAP-like (PsPSAPL) sequences from starry flounder and analysed their expression and antimicrobial activity based on cDNA and amino acid sequences. PsPSAPL showed conservation of three saposin B type domains at high levels, and PsPSAPL mRNA was relatively abundantly distributed in the brain and gills of healthy starry founders. PsPSAPL mRNA showed significant expression changes in response to viral haemorrhagic septicaemia virus and Streptococcus parauberis. Synthetic peptides (PsPSAPL-1 and -2), prepared based on amino acid sequences, were used to confirm as well as analyse the antimicrobial activity against bacteria and parasites. Consequently, PsPSAPL-1 and -2 were found to significantly inhibit the growth of various bacteria and kill the Miamiensis avidus. In addition, bacterial biofilm formation was significantly inhibited. Safety was also confirmed by analysing cell haemolysis. These results indicate the immunological function of PsPSAP and the potential antimicrobial activity of the AMPs PsPSAPL-1 and -2. •The Prosaposin-like (PSAPL) was identified by NGS analysis from Platichthys stellatus.•PsPSAPL showed high homology and sequence conservation with other species PSAPL.•PsPSAPL mRNA showed significant expression change due to pathogen infection.•The antimicrobial function and in vivo safety of PsPSAPL peptides were confirmed.