RRC ID 59885
Author Vo LK, Tsuzuki T, Kamada-Futagami Y, Chigwechokha PK, Honda A, Oishi K, Komatsu M, Shiozaki K.
Title Desialylation by Edwardsiella tarda is the initial step in the regulation of its invasiveness.
Journal Biochem J
Abstract Edwardsiella tarda is a gram-negative bacterium causing significant economic losses to aquaculture. E. tarda possesses NanA sialidase which removes sialic acids from α2-3 sialo-glycoprotein of host cells. However, the relationship between NanA sialidase activity and E. tarda invasiveness remains poorly understood. Furthermore, the pathway of sialic acid metabolism in E. tarda remains to be elucidated. We studied sialidase activity in several E. tarda strains and found that the pathogenic strains exhibited higher sialidase activity and greater up-regulation of the NanA mRNA level than non-pathogenic strain. Pathogenic strains also showed higher rates of infection in GAKS cells, and the infection was drastically suppressed by sialidase inhibitor. Additionally, NanA gene overexpression significantly increased infection and treatment of E. tarda with free sialic acid enhanced the rate of infection in GAKS cells. Sialic acid treatment enhanced mRNA levels of two N-acetylneuraminate lyases and one N-acetylneuraminate cytidylyltransferase. E. tarda uses sialic acid as a carbon source for growth via N-acetylneuraminate lyases. The strains with high N-acetylneuraminate cytidylyltransferase level showed greater sialylation of the lipopolysaccharides and glycoproteins. Our study establishes the significance of desialylation by E. tarda sialidase in the regulation of its invasiveness.
Volume 476(21)
Pages 3183-3196
Published 2019-11-15
DOI 10.1042/BCJ20190367
PII 220762
PMID 31654066
MeSH Bacterial Proteins / genetics Bacterial Proteins / metabolism Cell Line Edwardsiella tarda / genetics Edwardsiella tarda / metabolism Edwardsiella tarda / pathogenicity* Enterobacteriaceae Infections / microbiology* Humans N-Acetylneuraminic Acid / metabolism* Neuraminidase / genetics Neuraminidase / metabolism Virulence
IF 4.331
Times Cited 0
Human and Animal Cells GAKS(RCB1452)