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, respo ...

, 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. ...

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 to ...

). 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 A-kinase anchor protein 4 is a scaffold protein that in humans is encoded by the ''AKAP4'' gene. It involves in the intracellular signalling of protein kinase -A. AKAP4 is called as cancer /testis antigen (CTA), it belongs to a class of tumour lin ...

AKAP5 A-kinase anchor protein 5 is a protein that in humans is encoded by the ''AKAP5'' 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 sub ...

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 A-kinase anchor protein 7 isoform gamma is an enzyme that in humans is encoded by the ''AKAP7'' gene. Function This gene encodes a member of the A-kinase anchoring protein (AKAP) family, a group of functionally related proteins that bind to ...

* AKAP8 *

AKAP9 A-kinase anchor protein 9 is a protein that in humans is encoded by the ''AKAP9'' gene. AKAP9 is also known as Centrosome- and Golgi-localized protein kinase N-associated protein (CG-NAP) or AKAP350 or AKAP450 Function The A-kinase anchor prot ...

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 A-kinase anchor protein 11 is an enzyme that in humans is encoded by the ''AKAP11'' 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 s ...

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 t ...

AKAP13 A-kinase anchor protein 13 is a protein that in humans is encoded by the ''AKAP13'' gene. This protein is also called AKAP-Lbc because it encodes the lymphocyte blast crisis (Lbc) oncogene, and ARHGEF13/RhoGEF13 because it contains a guanine nucle ...

References

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