Title : Arylsulfatase LvARS2 regulates glycosaminoglycan sulfation and modulates white spot syndrome virus burden in Litopenaeus vannamei
Abstract:
Glycosaminoglycans (GAGs) and their sulfation patterns shape the extracellular matrix of crustacean barrier tissues and may influence pathogen attachment and infection. However, the enzymes controlling GAG sulfation in shrimp remain poorly understood. This study identified and annotated eight arylsulfatase (ARS) genes in the Pacific white shrimp, Litopenaeus vannamei, and investigated LvARS2, a highly expressed hepatopancreatic transcript, as a candidate regulator of sulfated GAG metabolism and white spot syndrome virus (WSSV) burden. Genome mining, domain and motif annotation, tissue transcript profiling, molecular cloning, recombinant protein production, enzyme assays, RNA-interference knockdown, recombinant-protein treatment, rescue experiments, dimethyl methylene blue quantification of total sulfated GAGs, and VP28-targeted qPCR were integrated. LvARS2 displayed a lysosomal-type biochemical profile, with maximal activity at pH 5.0 and 40 °C, marked calcium dependence, and a conserved formylglycine catalytic centre. In vivo, LvARS2 knockdown was associated with increased sulfated GAG accumulation in the hepatopancreas and gill at 24 and 48 hours and with a higher WSSV burden. Recombinant LvARS2 treatment produced the opposite pattern, reducing sulfated GAG levels and viral load, while the rescue treatment shifted both outcomes toward the control phenotype. The consistent directional responses across two barrier tissues support a model in which LvARS2 functions as an ARSB-type enzyme that modifies GAG sulfation and thereby alters extracellular-matrix chemistry relevant to viral susceptibility. These findings add a glycobiological dimension to crustacean immunity and identify LvARS2-mediated sulfation control as a potential biomarker and complementary target for disease management in shrimp aquaculture. Further work should resolve the affected GAG species and sulfation positions and assess the safety and feasibility of enzyme-based modulation under farming conditions.
