AKAP

The A-kinase anchor proteins (AKAPs) are a group of structurally diverse proteins, which have the common function of binding to the regulatory subunit of protein kinase A (PKA) and confining the holoenzyme to discrete locations within the cell. At least 20 AKAPs have been cloned. There are at least 50 members. Often named after their MW.


 * AKAP1
 * AKAP2
 * AKAP3
 * AKAP4
 * AKAP5
 * AKAP6
 * AKAP7
 * AKAP8
 * AKAP9
 * AKAP10
 * AKAP11
 * AKAP12
 * AKAP13

Function
AKAPs act as targeting devices that assemble signaling elements on a scaffold that itself targets to microdomains in cells. This allows specific targeting of substrates to be regulated by phosphorylation (by PKA) and dephosphorylation (by phosphatases). PKA binds directly to an AKAP by its regulatory subunits (RIα, RIIα, RIβ, RIIβ) to an amphipathic α-helix to which all AKAPs have in common. The AKAPs also bind other components including; phosphodiesterases (PDEs) which break down cAMP, phosphatases which dephosphorylate downstream PKA targets and also other kinases (PKC and MAPK). Some AKAPs are able to bind both regulatory subunits (RI & RII) of PKA and are dual-specific AKAPs (D-AKAP1 and D-AKAP2)