Cloning and sequencing of cDNA encoding the putative insect plasma membrane V-ATPase subunit A

For the first time a cDNA encoding subunit A of an invertebrate V-ATPase has been sequenced. The cDNA library was prepared from larval midgut of the tobacco hornworm, Manduca sexta, and screened with monoclonal antibodies to the midgut plasma membrane subunit A. From the cDNA sequence the insect subunit A is predicted to consist of 617 amino acids with a relative molecular mass of 68,162. The predicted primary structure is similar to that of the published eukaryotic subunit A proteins (Bos, Daucus, Saccharomyces and Neurospora); it most closely resembles the bovine amino acid sequences with which it has an 83% sequence identity.