Molecular Target Synopsis
Overview
Domains and Structures
Drugs and Clinical Candidates
Druggability
Chemistry
Ligand Efficiency Plot
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Interaction Network
Gene Expression
Gene Copy Number Variation
RNAi
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AKT2 (P31751) - Overview - Molecular Target Synopsis

Protein


AKT2, RAC-beta serine/threonine-protein kinase
Enzyme Classification 2.7.11.1
UniProt P31751

Also Known as AKT2_HUMAN, AKT2

AKT2 is one of 3 closely related serine/threonine-protein kinases (AKT1, AKT2 and AKT3) called the AKT kinase, and which regulate many processes including metabolism, proliferation, cell survival, growth and angiogenesis. This is mediated through serine and/or threonine phosphorylation of a range of downstream substrates. Over 100 substrate candidates have been reported so far, but for most of them, no isoform specificity has been reported. AKT is responsible of the regulation of glucose uptake by mediating insulin-induced translocation of the SLC2A4/GLUT4 glucose transporter to the cell surface. Phosphorylation of PTPN1 at 'Ser-50' negatively modulates its phosphatase activity preventing dephosphorylation of the insulin receptor and the attenuation of insulin signaling. Phosphorylation of TBC1D4 triggers the binding of this effector to inhibitory 14-3-3 proteins, which is required for insulin-stimulated glucose transport. AKT regulates also the storage of glucose in the form of glycogen by phosphorylating GSK3A at 'Ser-21' and GSK3B at 'Ser-9', resulting in inhibition of its kinase activity. Phosphorylation of GSK3 isoforms by AKT is also thought to be one mechanism by which cell proliferation is driven. AKT regulates also cell survival via the phosphorylation of MAP3K5 (apoptosis signal-related kinase). Phosphorylation of 'Ser-83' decreases MAP3K5 kinase activity stimulated by oxidative stress and thereby prevents apoptosis. AKT mediates insulin-stimulated protein synthesis by phosphorylating TSC2 at 'Ser-939' and 'Thr-1462', thereby activating mTORC1 signaling and leading to both phosphorylation of 4E-BP1 and in activation of RPS6KB1. AKT is involved in the phosphorylation of members of the FOXO factors (Forkhead family of transcription factors), leading to binding of 14-3-3 proteins and cytoplasmic localization. In particular, FOXO1 is phosphorylated at 'Thr-24', 'Ser-256' and 'Ser-319'. FOXO3 and FOXO4 are phosphorylated on equivalent sites. AKT has an important role in the regulation of NF-kappa-B-dependent gene transcription and positively regulates the activity of CREB1 (cyclic AMP (cAMP)-response element binding protein). The phosphorylation of CREB1 induces the binding of accessory proteins that are necessary for the transcription of pro-survival genes such as BCL2 and MCL1. AKT phosphorylates 'Ser-454' on ATP citrate lyase (ACLY), thereby potentially regulating ACLY activity and fatty acid synthesis. Activates the 3B isoform of cyclic nucleotide phosphodiesterase (PDE3B) via phosphorylation of 'Ser-273', resulting in reduced cyclic AMP levels and inhibition of lipolysis. Phosphorylates PIKFYVE on 'Ser-318', which results in increased PI(3)P-5 activity. The Rho GTPase-activating protein DLC1 is another substrate and its phosphorylation is implicated in the regulation cell proliferation and cell growth. AKT plays a role as key modulator of the AKT-mTOR signaling pathway controlling the tempo of the process of newborn neurons integration during adult neurogenesis, including correct neuron positioning, dendritic development and synapse formation. Signals downstream of phosphatidylinositol 3-kinase (PI(3)K) to mediate the effects of various growth factors such as platelet-derived growth factor (PDGF), epidermal growth factor (EGF), insulin and insulin-like growth factor I (IGF-I). AKT mediates the antiapoptotic effects of IGF-I. Essential for the SPATA13-mediated regulation of cell migration and adhesion assembly and disassembly. May be involved in the regulation of the placental development., One of the few specific substrates of AKT2 identified recently is PITX2. Phosphorylation of PITX2 impairs its association with the CCND1 mRNA-stabilizing complex thus shortening the half-life of CCND1. AKT2 seems also to be the principal isoform responsible of the regulation of glucose uptake. Phosphorylates C2CD5 on 'Ser-197' during insulin-stimulated adipocytes. AKT2 is also specifically involved in skeletal muscle differentiatio Interacts with BTBD10 (By similarity). Interacts with KCTD20 (By similarity). Interacts (via PH domain) with MTCP1, TCL1A AND TCL1B. Interacts with CLK2, PBH2 and TRAF6. Interacts (when phosphorylated) with CLIP3, the interaction promotes cell membrane localization (PubMed:19139280). Interacts with WDFY2 (via WD repeats 1-3) (PubMed:16792529).

2XH5
STRUCTURE OF 4-(4-TERT-BUTYLBENZYL)-1-(7H-PYRROLO(2,3-D) PYRIMIDIN-4-YL)PIPERIDIN-4-AMINE BOUND TO PKB
RCSB/PDB
Inspect Structure
See all 3D Structures for AKT2

Isoforms / Transcripts (Protein Coding)


Sub-cellular localization


UniProt: AKT2 is active in the following subcellular-locations: cell membrane, cytoplasm, early endosome, nucleus.
GO terms: AKT2 is active in the following subcellular-locations: cell cortex, cytosol, early endosome, intracellular membrane-bounded organelle, nucleoplasm, nucleus, plasma membrane, protein-containing complex, ruffle membrane.



UniProt
GO terms

Gene Copy Number Variation


In COSMIC - Cell Lines Project AKT2 has gain in 13 cell-lines, loss in 0 cell-lines and no signal in 992 cell-lines. (see details)

Gene Expression


In NCI60, the highest expressing cell lines are: OVCAR_3, SNB_19, OVCAR_4

In Array Express (RNA-seq of 675 commonly used human cancer cell lines), the highest expressing cell lines are: PANC-1, NIH:OVCAR-3, NCI-H820

In Array Express (RNA-seq of long poly adenylated RNA and long non poly adenylated RNA from ENCODE cell lines), the highest expressing cell lines are: SK-N-SH, K562, A549

(see details)

RNA Interference


AKT2 was reported in the following RNAI studies:

Cell - Large Scale Profiling of Kinase Dependencies in Cancer Cell Lines, the highest RNAi cell lines are: MIAPACA2, RMGI. (see details)

3D Structures


For AKT2 there are:
17 structures (21 chains) solved
11 are solved in complex with at least one small molecule ligand



(see details)
Molecular Target 3D Synopsis

Screening and Chemistry


AKT2 has been screened with 1995 compounds (3008 bioactivities), 690 compounds have bioactivities that show binding affinity of <= 500nM (857 bioactivities). (see details)