The expression of protein disulfide isomerase from Litopenaeus vannamei hemocytes is regulated by bacterial inoculation

A partial clone encoding a member of the protein disulfide isomerase (PDI) was isolated from a Litopenaeus vannamei hemocyte cDNA library. The 5′-end sequence was obtained by RACE. The complete sequence encodes for a 502-residues protein that contains two thioredoxin domains and the typical endoplasmic reticulum retention KDEL motif. Shrimp PDI is highly similar to the homologue protein described in both vertebrates and invertebrates. Changes in the shrimp PDI mRNA expression were observed after injection of Vibrio alginolyticus, suggesting that PDI is implicated in the immune defense system. This is the first report of a PDI in crustaceans.