Abstract
p53 is a transcription factor with capability of regulating diverse NF-κB dependent biological progresses such as inflammation and host defense, but the actual mechanism remains unrevealed. Herein, we firstly identified two novel alternatively spliced isoforms of p53 from Litopenaeus vannamei (LvΔNp53 and the full-length of p53, LvFLp53). We then established that the two p53 isoforms exerted opposite effects on regulating NF-κB induced antimicrobial peptides (AMPs) and white spot syndrome virus (WSSV) immediate-early (IE) genes expression, suggesting there could be a crosstalk between p53 and NF-κB pathways. Of note, both of the two p53 isoforms could interact directly with LvDorsal, a shrimp homolog of NF-κB. In addition, the activation of NF-κB mediated by LvDorsal was provoked by LvΔNp53 but suppressed by LvFLp53, and the increased NF-κB activity conferred by LvΔNp53 can be attenuated by LvFLp53. Furthermore, silencing of LvFLp53 in shrimp caused higher mortalities and virus loads under WSSV infection, whereas LvΔNp53-knockdown shrimps exhibited an opposed RNAi phenotype. Taken together, these findings present here provided some novel insight into different roles of shrimp p53 isoforms in immune response, and some information for us to understand the regulatory crosstalk between p53 pathway and NF-κB pathway in invertebrates.