Nuclear and mitochondrial subunits from the white shrimp Litopenaeus vannamei F₀F₁ ATP-synthase complex: CDNA sequence, molecular modeling, and mRNA quantification of atp9 and atp6

We studied for the first time the ATP-synthase complex from shrimp as a model to understand the basis of crustacean bioenergetics since they are exposed to endogenous processes as molting that demand high amount of energy. We analyzed the cDNA sequence of two subunits of the Fo sector from mitochondrial ATP-synthase in the white shrimp Litopenaeus vannamei. The nucleus encoded atp9 subunit presents a 773 bp sequence, containing a signal peptide sequence only observed in crustaceans, and the mitochondrial encoded atp6 subunit presents a sequence of 675 bp, and exhibits high identity with homologous sequences from invertebrate species. ATP9 and ATP6 protein structural models interaction suggest specific functional characteristics from both proteins in the mitochondrial enzyme. Differences in the steady-state mRNA levels of atp9 and atp6 from five different tissues correlate with tissue function. Moreover, significant changes in the mRNA levels of both subunits at different molt stages were detected. We discussed some insights about the enzyme structure and the regulation mechanisms from both ATP-synthase subunits related to the energy requirements of shrimp.