The role of tumor suppressor protein p53 in the mud crab (Scylla paramamosain) after Vibrio parahaemolyticus infection.

The tumor suppressor protein p53 plays important roles in DNA repair, cell cycle and genetic stability. In the present study, a p53 gene in the mud crab (Scylla paramamosain) (designated as Sp-53) was identified and characterized. The open reading frame of Sp-53 was comprised a 1383 bp, which encoded a putative protein of 460 amino acids. Sp-53 is expressed in all examined tissues, with the highest expression in hepatopancreas and hemocytes. Vibrio parahaemolyticus infection induced oxidative stress, and led to DNA damage. The Sp-53 transcriptions in hepatopancreas were significantly up-regulated after V. parahaemolyticus infection. RNA interference (RNAi) experiment was used to understand the roles of Sp-53 in response to V. parahaemolyticus infection. Knocking down Sp-53 in vivo significantly reduced the expression of the Mn-SOD, Gpx3 and caspase 3 after V. parahaemolyticus infection. Moreover, the mortality of mud crabs and DNA damage in Sp-53-silenced mud crab challenged with V. parahaemolyticus were significantly higher than those in the control group. All these results suggested that Sp-53 played an important role in responses to V. parahaemolyticus infection through its participation in regulation of antioxidant defense, DNA repair and apoptosis.