Two C-type lectins (ReCTL-1, ReCTL-2) from Rimicaris exoculata display broad nonself recognition spectrum with novel carbohydrate binding specificity

Publication date: Available online 30 November 2019Source: Fish & Shellfish ImmunologyAuthor(s): Gaoyang Wang, Yutong Lei, Ting Kang, Zhi Li, Hui Fei, Shun Yang, Peng Zhou, Chunsheng Wang, Zhengbing Lv, Mengmeng Huang, Xuewei XuAbstractC-type lectins are Ca2+-dependent carbohydrate-binding proteins containing one or more carbohydrate-recognition domains (CRDs). C-type lectins play crucial roles in innate immunity, including nonself-recognition and pathogen elimination. In the present study, two C-type lectins (designated ReCTL-1 and ReCTL-2) were identified from the shrimp Rimicaris exoculata which dwells in deep-sea hydrothermal vents. The open reading frames of ReCTL-1 and ReCTL-2 encoded polypeptides of 171 and 166 amino acids respectively, which were both composed of a signal peptide and a single CRD. The key motifs determining the carbohydrate binding specificity of ReCTL-1 and ReCTL-2 were respectively Glu–Pro–Ala (EPA) and Gln–Pro–Asn (QPN), which were firstly discovered in R. exoculata. ReCTL-1 and ReCTL-2 displayed similar pathogen-associated molecular pattern (PAMP) binding features and they bound three PAMPs—β-glucan, lipopolysaccharide and peptidoglycan—with relatively high affinity. In addition, both could efficiently recognize and bind Gram-positive bacteria, Gram-negative bacteria and fungi. However, ReCTL-1 and ReCTL-2 exhibited different microbial agglutination activities: ReCTL-1 agglutinated Staphylococcus aureus and Saccharomyces cerevisiae, w...
Source: Fish and Shellfish Immunology - Category: Biology Source Type: research