A novel l-rhamnose-binding lectin participates in defending against bacterial infection in zebrafish.
Fish Shellfish Immunol
; 134: 108553, 2023 Mar.
Article
em En
| MEDLINE
| ID: mdl-36693487
ABSTRACT
l-rhamnose-binding lectin (RBL), which is a class of animal lectins independent of Ca2+, can specifically bind l-rhamnose or d-galactose. Although several lectins in zebrafish have been reported, their functional mechanisms have not been fully uncovered. In this study, we discovered a novel l-rhamnose binding lectin (DrRBL) and studied its innate immune function. The DrRBL protein contains only one carbohydrate-recognition domain (CRD), which includes two strictly conserved motifs, "YGR" and "DPC". DrRBL was detected in all tested tissues and was present at high levels in the spleen, hepatopancreas and skin. After Aeromonas hydrophila challenge, the DrRBL mRNA level was significantly upregulated. Additionally, DrRBL was secreted into the extracellular matrix. Recombinant DrRBL (rDrRBL) could significantly inhibit the growth of gram-positive/negative bacteria, bind to several bacteria and cause obvious agglutination. The rDrRBL protein could combine with polysaccharides, such as PGN and LPS, rather than LTA. A more detailed study showed that rDrRBL could combine with monosaccharides, such as mannose, rhamnose and glucose, which are important components of PGN and LPS. However, rDrRBL could not bind to ribitol, which is an important component of LTA. The DrRBL deletion mutants, DrRBLΔ144-150 and DrRBLΔ198-200, were also constructed. DrRBLΔ144-150 ("ANYGRTD" deficient) showed weak bacterial inhibiting ability. However, DrRBLΔ198-200 ("DPC" deficient) showed weak agglutination ability. These results suggest that the "DPC" domain is important for agglutination. The conserved domain "ANYGRTD" is essential for inhibiting bacterial growth.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Infecções Bacterianas
/
Lectinas
Limite:
Animals
Idioma:
En
Revista:
Fish Shellfish Immunol
Assunto da revista:
BIOLOGIA
/
MEDICINA VETERINARIA
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
China