Characterization and functional analysis of a novel mannose-binding lectin from the swimming crab Portunus trituberculatus. Issue 89 (June 2019)

• Record Type: Journal Article
• Authors: Zhang, Mengjie; Liu, Yuan; Song, Chengwen; Ning, Junhao; Cui, Zhaoxia
• Is Part Of: Fish & shellfish immunology. Issue 89(2019)
• Page Start: 448
• Page End: 457
• Publication Date: 2019-06
• Subjects: Portunus trituberculatus -- Mannose-binding lectin -- Pattern recognition receptor -- Antimicrobial activities; Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2019.04.007
• Languages: English
• ISSNs: 1050-4648

Abstract

Abstract: Mannose-binding lectin (MBL) is a pattern recognition receptor (PRR) that plays an important role in the innate immune response. In this study, a novel mannose-binding lectin was cloned from the swimmimg crab Portunus trituberculatus (designated as PtMBL). The complete cDNA of PtMBL gene was 1208 bp in length with an open reading frame (ORF) of 732 bp that encoded 244 amino acid proteins. PtMBL shared lower amino acid similarity with other MBLs, yet it contained the conserved carbohydrate-recognition domain (CRD) with QPD motif and was clearly member of the collectin family. PtMBL transcripts were mainly detected in eyestalk and gill with sexually dimorphic expression. The temporal expression of PtMBL in hemocytes showed different activation times after challenged with Vibrio alginolyticus, Micrococcus luteus and Pichia pastoris . The recombinant PtMBL protein revealed antimicrobial activity against the tested Gram-negative and Gram-positive bacteria. It could also bind and agglutinate (Ca 2+ -dependent) both bacteria and yeast. Furthermore, the agglutinating activity could be inhibited by bothd -galactose andd -mannose, suggesting the broader pathogen-associated molecular patterns (PAMPs) recognition spectrum of PtMBL. These results together indicate that PtMBL could serve as not only a PRR in immune recognition but also a potential antibacterial protein in the innate immune response of crab. Highlights: PtMBL contained the conserved carbohydrate-recognition domain with QPD motif. PtMBL transcripts could be quickly induced by bacterial challenge. The recombinant PtMBL exhibited antimicrobial activity against the tested bacteria. The rPtMBL could bind and agglutinate (Ca 2+ -dependent) both bacteria and yeast. The rPtMBL could not only bindd -galactose but alsod -mannose.