The A-kinase anchoring proteins or A-kinase anchor proteins (AKAPs) are a group of structurally diverse
proteins
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respondi ...
, which have the common function of binding to the regulatory subunit of
protein kinase A
In cell biology, protein kinase A (PKA) is a family of enzymes whose activity is dependent on cellular levels of cyclic AMP (cAMP). PKA is also known as cAMP-dependent protein kinase (). PKA has several functions in the cell, including regulatio ...
(PKA) and confining the
holoenzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...
to discrete locations within the cell.
At least 20 AKAPs have been cloned.
There are at least 50 members, often named after their molecular mass.
Function
AKAPs act as
scaffold proteins wherein they bind PKA and other signaling proteins and physically tether these multi-protein complexes to specific locations, such as the nucleus, in cells.
This allows specific targeting of substrates to be regulated by phosphorylation (by
PKA
PKA may refer to:
* Professionally known as:
** Pen name
** Stage persona
* p''K''a, the symbol for the acid dissociation constant at logarithmic scale
* Protein kinase A, a class of cAMP-dependent enzymes
* Pi Kappa Alpha, the North-American so ...
) and dephosphorylation (by phosphatases).
The dimerization and docking (D/D) domain of the regulatory subunit dimer of PKA binds with the A-kinase binding (AKB) domain (an
amphipathic
An amphiphile (from the Greek αμφις amphis, both, and φιλíα philia, love, friendship), or amphipath, is a chemical compound possessing both hydrophilic (''water-loving'', polar) and lipophilic (''fat-loving'') properties. Such a compoun ...
helix) of AKAP. 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
A mitogen-activated protein kinase (MAPK or MAP kinase) is a type of protein kinase that is specific to the amino acids serine and threonine (i.e., a serine/threonine-specific protein kinase). MAPKs are involved in directing cellular responses ...
). Some AKAPs are able to bind both regulatory subunits (RI & RII) of PKA and are dual-specific AKAPs (D-AKAP1 and D-AKAP2).
List of AKAPs
*
AKAP1
*
AKAP2
*
AKAP3
A-kinase anchor protein 3 is an enzyme that in humans is encoded by the ''AKAP3'' gene.
Function
The A-kinase anchor proteins (AKAPs) are a group of structurally diverse proteins, which have the common function of binding to the regulatory subu ...
*
AKAP4
*
AKAP5
*
AKAP6
A-kinase anchor protein 6 is an enzyme that in humans is encoded by the ''AKAP6'' gene.
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 prot ...
*
AKAP7
*
AKAP8
*
AKAP9
*
AKAP10
A kinase anchor protein 10, mitochondrial is an enzyme that in humans is encoded by the ''AKAP10'' gene.
Function
The A-kinase anchor proteins (AKAPs) are a group of structurally diverse proteins, which have the common function of binding to t ...
*
AKAP11
*
AKAP12
A-kinase anchor protein 12, aka AKAP250, is an enzyme that in humans is encoded by the ''AKAP12'' gene.
Function
The A-kinase anchor proteins (AKAPs) are a group of structurally diverse proteins, which have the common function of binding to ...
*
AKAP13
References
{{DEFAULTSORT:Akap