A ferritin gene from Procambarus clarkii, molecular characterization and in response to heavy metal stress and lipopolysaccharide challenge.

Ferritin plays important roles in iron storage, detoxification, and immune response. Here, a ferritin gene (PcFer) was identified in Procambarus clarkii, an economically important freshwater crayfish. Full-length PcFer cDNA was 1022-bp, including a 135-bp 5'-untranslated region (UTR) with a typical iron responsive element, a 374-bp 3'-UTR, and a 513-bp open reading frame encoding a polypeptide of 170 amino acids which contained the Ferritin domain. PcFer has ion binding sites, a ferrihydrite nucleation center, and an iron ion channel. PcFer is phylogenetically closely-related to Pacifastacus leniusculus and Eriocheir sinensis ferritins. Real-time quantitative reverse-transcription PCR analysis showed that PcFer was expressed in all tested P. clarkii tissues, and expressed most in hepatopancreas. After challenge with various heavy metals and lipopolysaccharide, respectively, the hepatopancreatic expression levels of PcFer were markedly upregulated. These results suggest that expression of PcFer might be involved in immune defense and protection of P. clarkii against heavy metal stress.