A cytosolic sensor, PmDDX41, mediates antiviral immune response in black tiger shrimp Penaeus monodon

摘要

AbstractDEAD (Asp-Glu-Ala-Asp)-box polypeptide 41 (DDX41), a receptor belonging to the DExD family, has recently been identified as an intracellular DNA sensor in vertebrates. Here, we report on the identification and functional characterization ofPmDDX41, the first cytosolic DNA sensor in shrimp. By searching aPenaeus monodonexpressed sequence tag (EST) database (http://pmonodon.biotec.or.th), three cDNA fragments exhibiting similarity to DDX41 in various species were identified and assembled, resulting in a complete open reading frame ofPmDDX41 that contains 1863-bp and encodes a putative protein of 620 amino acids.PmDDX41 shares 83% and 79% similarity to DDX41 homolog from the beeApis floreaand fruit flyDrosophila melanogaster,respectivelyand contains three conserved domains in the protein: DEADc domain, HELICc domain, and zinc finger domain. The transcript ofPmDDX41 was detected in all tested tissues and was up-regulated upon infection with a DNA virus, white spot syndrome virus (WSSV). However,PmDDX41 mRNA expression was not significantly changed and down-regulated in response to a bacterium,Vibrio harveyi, or an RNA virus, yellow head virus (YHV), respectively, compared with the control phosphate-buffered saline-injected shrimp. Furthermore, the suppression ofPm