The plasma membrane H+-V-ATPase from tobacco hornworm midgut

The midgut plasma membrane V-ATPase from larval Manduca sexta, the tobacco hornworm, is the sole energizer of any epithelial ion transport in this tis sue and is responsible for the alkalinization of the gut lumen up to a pH o f more than 11. This mini-review deals with those topics of research on thi s enzyme which may have contributed or are expected to contribute novel and general aspects to the field of V-ATPases. Topics dealt with include novel subunits or the quaternary structure of the V-1 complex, as well as the re gulation of the enzyme's function by reversible dissociation of the V-1 fro m the V-0 complexes and by genetic control on the transcriptional and postt ranscriptional level.