A C‐type lectin with antibacterial activity in weather loach, Misgurnus anguillicaudatus

Abstract

C‐type lectins are carbohydrate‐binding proteins that play important roles in immunity by serving as pattern recognition receptors. In the present study, a novel nattectin‐like C‐type lectin was obtained from the weather loach, Misgurnus anguillicaudatus, designated as MaCTL. MaCTL encodes a peptide with 165 amino acids, with a signal peptide and a single C‐type lectin domain (CTLD), containing a galactose‐specific QPD motif and a conserved Ca2+‐binding site. Transcripts of MaCTL were significantly upregulated after immune challenge with its pathogen A. hydrophila. In vitro assays with recombinant MaCTL protein revealed that it exhibited hemagglutinating and bacterial agglutinating activities, in a Ca2+‐dependent manner. MaCTL was found to bind to a wide range of bacteria, as well as bind to bacterial polysaccharides LPS and PGN. Moreover, MaCTL displayed antimicrobial activity by inhibiting the growth of bacteria. These results collectively suggest that MaCTL is involved in the antibacterial defence of weather loach.

Hallmarks of crustacean immune hemocytes at single-cell resolution

“…As reported, farnesoic acid O-methyltransferase, a key enzyme involved in methyl farnesoate (a crustacean equivalent of insect juvenile hormone) synthesis, is upregulated after Vibrio anguillarum and WSSV challenge ( 35 ). Galactose-specific nattectin-like lectin is a kind of C-type lectin which functions in antibacterial defense ( 36 ). However, this protein has not been reported in crustaceans.…”

“…CC6 was enriched in the genes encoding hyperglycemic hormone peptide 2 precursor and sacsin-like protein ( Figure 4B ). Hyperglycemic hormone peptide 2 precursor, mainly in granular cells and semi-granular cells ( 44 ), is a polypeptide hormone involved in environmental stress ( 36 ). In humans, sacsin functions as a regulator of heat shock protein 70 (Hsp70), a stress protein involved in environmental stress ( 45 ).…”

An Update of Lectins from Marine Organisms: Characterization, Extraction Methodology, and Potential Biofunctional Applications

“…The affinity of CTLDcps to sugars, especially galactose, is facilitated by a high density of proline residues [ 85 ]. A CTL from weather loach ( Misgurnus anguillicaudatus ) (MaCTL) is composed of 165 amino acids with a C-type lectin domain (CTLD) and a galactose-specific QPD (Gln-Pro-Asp) motif was upregulated by weather loach invasion in a Ca 2+ -dependent manner [ 86 ]. Likewise, the expression of Nattectin-like (CaNTC) protein in goldfish ( Carassius auratus ) was upregulated in the liver, spleen, and kidney by Aeromonas hydrophilia invasion.…”

“…Given their ability to selectively recognize and bind the carbohydrate moiety of glycoconjugates, one of the most prominent physiological function of lectins in marine organisms is their role as potent defense molecules where they are involved in processes such as non-self-recognition, inflammation, opsonization, phagocytosis, encapsulation, and lysis of foreign cells [ 111 , 112 ]. The ability of lectins to trigger multiple immunological responses is essential for autoimmunity and management of infection in fish [ 63 , 72 , 86 , 113 ]. For instance, the lily type lectins, CsLTL-1 and CsLTL-2, are crucial immune genes in stripped murrel Channa striatus for selectively recognizing and eliminating pathogens by disrupting the cell membrane [ 113 , 114 ].…”

Crucial roles of a novel exoskeletal‐derived lectin in innate immunity of the oriental river prawn, Macrobrachium nipponense

“…PtCLec1, detected mainly in the hepatopancreas of Portunus trituberculatus , could mediate pathogen recognition and might act as an opsonin in pathogen elimination (Su et al., 2020). A stomach‐specific lectin, PcLec obtained from Procambarus clarkia exhibited bacterial binding and agglutination activity as well as antimicrobial activity (Zhang, Han, et al., 2020; Zhang, Yang, et al., 2020). PcLec3, enriched expressed in hemocytes and hepatopancreas of the red swamp crayfish P. clarkia , acted as a hemocyte adhesion molecule to promote hemocyte phagocytosis against invasive Vibrio anguillarum (Zhang et al., 2016).…”