Adenylyl cyclase type 7 is the predominant isoform in the bovine retinal pigment epithelium

The retinal pigment epithelium (RPE) fulfills important supporting tasks to maintain the visual functions of the sensorineural retina. One major signa lling mechanism by which adjacent tissues impinge on the RPE is the adenyly l cyclase (AC)/cAMP pathway. In the RPE, cAMP seems to modulate unique func tions such as the phagocytosis of discs shed from the rod outer segments, t ransport of vitamin A or the ion and fluid control in the subretinal space. We analyzed the AC expression pattern in the retina and the RPE and found AC type 7 to be almost the only isoform expressed in the RPE. We cloned AC type 7 from a cDNA library established with fresh bovine RPE, expressed thi s isoform in eukaryotic cells and characterized some of its properties.