The ferritin gene in ridgetail white prawn Exopalaemon carinicauda: cloning, expression and function.

Ferritin, a primary iron storage protein, plays an important role in iron homeostasis. In this study, a ferritin cDNA (EcFer) with a 516 bp open reading frame (ORF) was obtained from Exopalaemon carinicauda (Holthuis) which encodes a 171 amino acid protein. At the 5-terminal untranslated region (5'-UTR), there is a complete iron-responsive element (IRE). EcFer mRNA was mainly expressed in the hepatopancreas and its expression was significantly up-regulated at 12, 24, and 48 h after the shrimp was exposed to CuSO4 and CdCl2. The transcript of EcFer was found to be extremely less or even absent at the gastrula and zoea stage. From the egg protozoea stage, the expression of EcFer was significantly up-regulated compared to that of the gastrula stage. In addition, EcFer was successfully expressed in Pichia pastoris and the purified rEcFer by size chromatography could uptake iron. These results suggest that EcFer plays important roles in the iron involved metabolism in shrimp.