Adenylyl cyclase
Adenylyl Cyclase is the enzyme that converts ATP into Cyclic AMP (cAMP) which is a secondary messenger.It has a major role in activating of enzymes and hormones for example: epinephrine, vasopressin and glucagon [1]. It is an integral membrane protein that has the structure of two bundles of six transmembrane segments and two catalytic domains that extend as loops into the cytoplasm. The enzyme can exist in at least 9 isoforms that are regulated in different ways by different G protein coupled receptors.
PK8 Phosphorylates Phosphodiesterase 3D, which lowers cAMP concerntration in the cells through hydrolysis. PK8 also has a negative feedback effect on PKA, decreasing adenylyl cyclase activity as a result. This lowers cAMP levels even more.
Reference
- ↑ Heldin and Purton:(1996:223)