Protein kinase B

Last updated

AKT1
Crystal structure of Akt-1-inhibitor complexes.png
Ribbon Representation of crystal structure of Akt-1-inhibitor complexes. [1]
Identifiers
Symbol AKT1
Entrez 207
HUGO 391
OMIM 164730
RefSeq NM_005163
UniProt P31749
Other data
Locus Chr. 14 q32.32-32.33
AKT2
3D0E Ribbon.png
Crystal structure of Akt-2-inhibitor complexes. [2]
Identifiers
Symbol AKT2
Entrez 208
HUGO 392
OMIM 164731
RefSeq NM_001626
UniProt P31751
Other data
Locus Chr. 19 q13.1-13.2
AKT3
Identifiers
Symbol AKT3
Entrez 10000
HUGO 393
OMIM 611223
RefSeq NM_181690
UniProt Q9Y243
Other data
Locus Chr. 1 q43-44

Protein kinase B (PKB), also known as Akt, is a serine/threonine-specific protein kinase that plays a key role in multiple cellular processes such as glucose metabolism, apoptosis, cell proliferation, transcription and cell migration.

Serine/threonine-specific protein kinase

A serine/threonine protein kinase is a kinase enzyme that phosphorylates the OH group of serine or threonine. At least 125 of the 500+ human protein kinases are serine/threonine kinases (STK).

Apoptosis programmed cell death process

Apoptosis is a form of programmed cell death that occurs in multicellular organisms. Biochemical events lead to characteristic cell changes (morphology) and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, chromosomal DNA fragmentation, and global mRNA decay. The average adult human loses between 50 and 70 billion cells each day due to apoptosis. For an average human child between the ages of 8 to 14 year old approximately 20 to 30 billion cells die per day.

Cell migration is a central process in the development and maintenance of multicellular organisms. Tissue formation during embryonic development, wound healing and immune responses all require the orchestrated movement of cells in particular directions to specific locations. Cells often migrate in response to specific external signals, including chemical signals and mechanical signals. Errors during this process have serious consequences, including intellectual disability, vascular disease, tumor formation and metastasis. An understanding of the mechanism by which cells migrate may lead to the development of novel therapeutic strategies for controlling, for example, invasive tumour cells.

Contents

Family members - Isoforms

Akt1 is involved in cellular survival pathways, by inhibiting apoptotic processes. Akt1 is also able to induce protein synthesis pathways, and is therefore a key signaling protein in the cellular pathways that lead to skeletal muscle hypertrophy, and general tissue growth. Mouse model with complete deletion of Akt1 manifests growth retardation and increased spontaneous apoptosis in tissues such as testes and thymus. [3] Since it can block apoptosis, and thereby promote cell survival, Akt1 has been implicated as a major factor in many types of cancer. Akt (now also called Akt1) was originally identified as the oncogene in the transforming retrovirus, AKT8. [4]

Oncogene gene that has the potential to cause cancer

An oncogene is a gene that has the potential to cause cancer. In tumor cells, they are often mutated or expressed at high levels.

Retrovirus family of viruses

A retrovirus is a type of RNA virus that inserts a copy of its genome into the DNA of a host cell that it invades, thus changing the genome of that cell. Such viruses are specifically classified as single-stranded positive-sense RNA viruses.

Akt2 is an important signaling molecule in the insulin signaling pathway. It is required to induce glucose transport. In a mouse which is null for Akt1 but normal for Akt2, glucose homeostasis is unperturbed, but the animals are smaller, consistent with a role for Akt1 in growth. In contrast, mice which do not have Akt2, but have normal Akt1, have mild growth deficiency and display a diabetic phenotype (insulin resistance), again consistent with the idea that Akt2 is more specific for the insulin receptor signaling pathway. [5]

Insulin resistance (IR) is considered as a pathological condition in which cells fail to respond normally to the hormone insulin. To prevent hyperglycemia and noticeable organ damage over time, the body produces insulin when glucose starts to be released into the bloodstream, primarily from the digestion of carbohydrates in the diet. Under normal conditions of insulin reactivity, this insulin response triggers glucose being taken into body cells, to be used for energy, and inhibits the body from using fat for energy, thereby causing the concentration of glucose in the blood to decrease as a result, staying within the normal range even when a large amount of carbohydrates is consumed. Carbohydrates comprise simple sugars, i.e. monosaccharides, such as glucose and fructose, disaccharides, such as cane sugar, and polysaccharides, e.g. starches. Fructose, which is metabolised into triglycerides in the liver, stimulates insulin production through another mechanism, and can have a more potent effect than other carbohydrates. A habitually high intake of carbohydrates, and particularly fructose, e.g. with sweetened beverages, contributes to insulin resistance and has been linked to weight gain and obesity. If excess blood sugar is not sufficiently absorbed by cells even in the presence of insulin, the increase in the level of blood sugar can result in the classic hyperglycemic triad of polyphagia, polydipsia, and polyuria. Avoiding carbohydrates and sugars, a no-carbohydrate diet or fasting can reverse insulin resistance.

Insulin receptor protein-coding gene in the species Homo sapiens

The insulin receptor (IR) is a transmembrane receptor that is activated by insulin, IGF-I, IGF-II and belongs to the large class of tyrosine kinase receptors. Metabolically, the insulin receptor plays a key role in the regulation of glucose homeostasis, a functional process that under degenerate conditions may result in a range of clinical manifestations including diabetes and cancer. Insulin signalling controls access to blood glucose in body cells. When insulin falls, especially in those with high insulin sensitivity, body cells begin only to have access to lipids that do not require transport across the membrane. So, in this way, insulin is the key regulator of fat metabolism as well. Biochemically, the insulin receptor is encoded by a single gene INSR, from which alternate splicing during transcription results in either IR-A or IR-B isoforms. Downstream post-translational events of either isoform result in the formation of a proteolytically cleaved α and β subunit, which upon combination are ultimately capable of homo or hetero-dimerisation to produce the ≈320 kDa disulfide-linked transmembrane insulin receptor.

Akt isoforms are overexpressed in a variety of human tumors, and, at the genomic level, are amplified in gastric adenocarcinomas (Akt1), ovarian (Akt2), pancreatic (Akt2) and breast (Akt2) cancer. [6] [7]

The role of Akt3 is less clear, though it appears to be predominantly expressed in the brain. It has been reported that mice lacking Akt3 have small brains. [8]

Name

The name Akt does not refer to its function. The "Ak" in Akt was a temporary classification name for a mouse that developed spontaneous thymic lymphomas. The "t" stands for 'thymoma'; the letter was added when a transforming retrovirus was isolated from the Ak strain, which was termed "Akt-8". When the oncogene encoded in this virus was discovered, it was termed v-Akt. Thus, the later identified human analogues were named accordingly.[ citation needed ]

Thymoma A thymus cancer that derives from epithelial cells located in the thymus. The tumor cells in a thymoma look similar to the normal cells of the thymus, grow slowly, and rarely spread beyond the thymus.

A thymoma is a tumor originating from the epithelial cells of the thymus that may be benign or malignant. Thymomas are frequently associated with the neuromuscular disorder myasthenia gravis; thymoma is found in 20% of patients with myasthenia gravis. Once diagnosed, thymomas may be removed surgically. In the rare case of a malignant tumor, chemotherapy may be used.

Regulation

Akt1 is involved in the PI3K/AKT/mTOR pathway and other signaling pathways.[ citation needed ]

Binding phospholipids

Akt possesses a protein domain known as a PH domain, or Pleckstrin Homology domain, named after Pleckstrin, the protein in which it was first discovered. This domain binds to phosphoinositides with high affinity. In the case of the PH domain of Akt, it binds either PIP3 (phosphatidylinositol (3,4,5)-trisphosphate, PtdIns(3,4,5)P3) or PIP2 (phosphatidylinositol (3,4)-bisphosphate, PtdIns(3,4)P2). [9] This is useful for control of cellular signaling because the di-phosphorylated phosphoinositide PIP2 is only phosphorylated by the family of enzymes, PI 3-kinases (phosphoinositide 3-kinase or PI3-K), and only upon receipt of chemical messengers which tell the cell to begin the growth process. For example, PI 3-kinases may be activated by a G protein coupled receptor or receptor tyrosine kinase such as the insulin receptor. Once activated, PI 3-kinase phosphorylates PIP2 to form PIP3.

Phosphorylation

Once correctly positioned at the membrane via binding of PIP3, Akt can then be phosphorylated by its activating kinases, phosphoinositide dependent kinase 1 (PDPK1 at threonine 308) and the mammalian target of rapamycin complex 2 (mTORC2 at serine 473), [10] [11] first by mTORC2. mTORC2 therefore functionally acts as the long-sought PDK2 molecule, although other molecules, including integrin-linked kinase (ILK) and mitogen-activated protein kinase-activated protein kinase-2 (MAPKAPK2) can also serve as PDK2. Phosphorylation by mTORC2 stimulates the subsequent phosphorylation of Akt by PDPK1.

Activated Akt can then go on to activate or deactivate its myriad substrates (e.g. mTOR) via its kinase activity.

Besides being a downstream effector of PI 3-kinases, Akt can also be activated in a PI 3-kinase-independent manner. [12] ACK1 or TNK2, a non-receptor tyrosine kinase, phosphorylates Akt at its tyrosine 176 residue, leading to its activation in PI 3-kinase-independent manner. [12] Studies have suggested that cAMP-elevating agents could also activate Akt through protein kinase A (PKA) in the presence of insulin. [13]

Ubiquitination

Akt is normally phosphorylated at position T450 in the turn motif when Akt is translated. If Akt is not phosphorylated at this position, Akt does not fold in the right way. The T450-non-phosphorylated misfolded Akt is ubiquitinated and degraded by the proteasome. Akt is also phosphorylated at T308 and S473 during IGF-1 response, and the resulting polyphosphorylated Akt is ubiquitinated partly by E3 ligase NEDD4. Most of the ubiquitinated-phosphorylated-Akt is degraded by the proteasome, while a small amount of phosphorylated-Akt translocates to the nucleus in a ubiquitination-dependent way to phosphorylate its substrate. A cancer-derived mutant Akt (E17K) is more readily ubiquitinated and phosphorylated than the wild type Akt. The ubiquitinated-phosphorylated-Akt (E17K) translocates more efficiently to the nucleus than the wild type Akt. This mechanism may contribute to E17K-Akt-induced cancer in humans. [14]

Lipid phosphatases and PIP3

PI3K-dependent Akt activation can be regulated through the tumor suppressor PTEN, which works essentially as the opposite of PI3K mentioned above. [15] PTEN acts as a phosphatase to dephosphorylate PIP3 back to PIP2. This removes the membrane-localization factor from the Akt signaling pathway. Without this localization, the rate of Akt activation decreases significantly, as do all of the downstream pathways that depend on Akt for activation.

PIP3 can also be de-phosphorylated at the "5" position by the SHIP family of inositol phosphatases, SHIP1 and SHIP2. These poly-phosphate inositol phosphatases dephosphorylate PIP3 to form PIP2.

Protein phosphatases

The phosphatases in the PHLPP family, PHLPP1 and PHLPP2 have been shown to directly de-phosphorylate, and therefore inactivate, distinct Akt isoforms. PHLPP2 dephosphorylates Akt1 and Akt3, whereas PHLPP1 is specific for Akt 2 and Akt3.[ citation needed ]

Function

Akt regulates cellular survival [16] and metabolism by binding and regulating many downstream effectors, e.g. Nuclear Factor-κB, Bcl-2 family proteins, master lysosomal regulator TFEB and murine double minute 2 (MDM2).

Cell survival

Overview of signal transduction pathways involved in apoptosis. Signal transduction pathways.svg
Overview of signal transduction pathways involved in apoptosis.

Akt could promote growth factor-mediated cell survival both directly and indirectly. BAD is a pro-apoptotic protein of the Bcl-2 family. Akt could phosphorylate BAD on Ser136, [17] which makes BAD dissociate from the Bcl-2/Bcl-X complex and lose the pro-apoptotic function. [18] Akt could also activate NF-κB via regulating IκB kinase (IKK), thus result in transcription of pro-survival genes. [19]

Cell cycle

Akt is known to play a role in the cell cycle. Under various circumstances, activation of Akt was shown to overcome cell cycle arrest in G1 [20] and G2 [21] phases. Moreover, activated Akt may enable proliferation and survival of cells that have sustained a potentially mutagenic impact and, therefore, may contribute to acquisition of mutations in other genes.

Metabolism

Akt2 is required for the insulin-induced translocation of glucose transporter 4 (GLUT4) to the plasma membrane. Glycogen synthase kinase 3 (GSK-3) could be inhibited upon phosphorylation by Akt, which results in increase of glycogen synthesis. GSK3 is also involved in Wnt signaling cascade, so Akt might be also implicated in the Wnt pathway. Still unknown role in HCV induced steatosis.

Lysosomal biogenesis and autophagy

Akt regulates TFEB, a master controller of lysosomal biogenesis, [22] by direct phosphorylation at serine 467. [23] Phosphorylated TFEB is excluded from the nucleus and less active. [23] Pharmacological inhibition of Akt promotes nuclear translocation of TFEB, lysosomal biogenesis and autophagy. [23]

Angiogenesis

Akt1 has also been implicated in angiogenesis and tumor development. Although deficiency of Akt1 in mice inhibited physiological angiogenesis, it enhanced pathological angiogenesis and tumor growth associated with matrix abnormalities in skin and blood vessels. [24] [25]

Clinical relevance

Akt is associated with tumor cell survival, proliferation, and invasiveness. The activation of Akt is also one of the most frequent alterations observed in human cancer and tumor cells. Tumor cells that have constantly active Akt may depend on Akt for survival. [26] Therefore, understanding Akt and its pathways is important for the creation of better therapies to treat cancer and tumor cells. A mosaic-activating mutation (c. 49G→A, p.Glu17Lys) in AKT1 is associated with the Proteus Syndrome, which causes overgrowth of skin, connective tissue, brain and other tissues. [27]

AKT inhibitors

Because of the Akt functions above, Akt inhibitors may treat cancers such as neuroblastoma. Some Akt inhibitors have undergone clinical trials. In 2007 VQD-002 had a phase I trial. [28] In 2010 Perifosine reached phase II. [29] but it failed phase III in 2012.

Miltefosine is approved for leishmaniasis and under investigation for other indications including HIV.

AKT is now thought to be the "key" for cell entry by HSV-1 and HSV-2 (herpes virus: oral and genital, respectively). Intracellular calcium release by the cell allows for entry by the herpes virus; the virus activates AKT, which in turn causes the release of calcium. Treating the cells with AKT inhibitors before virus exposure leads to a significantly lower rate of infection. [30]

MK-2206 reported phase 1 results for advanced solid tumors in 2011, [31] and subsequently has undergone numerous phase II studies for a wide variety of cancer types. [32]

In 2013 AZD5363 reported phase I results regarding solid tumors. [33] with a study of AZD5363 with olaparib reporting in 2016. [34]

A new type of Akt inhibitor has been discovered. [35]

Ipatasertib is in phase II trials for breast cancer. [36]

Decreased AKT can cause deleterious effects

AKT activation is associated with many malignancies; however, a research group from Massachusetts General Hospital and Harvard University unexpectedly observed a converse role for AKT and one of its downstream effector FOXOs in acute myeloid leukemia (AML). They claimed that low levels of AKT activity associated with elevated levels of FOXOs are required to maintain the function and immature state of leukemia-initiating cells (LICs). FOXOs are active, implying reduced Akt activity, in ∼40% of AML patient samples regardless of genetic subtype; and either activation of Akt or compound deletion of FoxO1/3/4 reduced leukemic cell growth in a mouse model. [37]

Hyperactivation of AKT can cause deleterious effects

Two recent studies show that AKT1 is involved in Juvenile Granulosa Cell tumors (JGCT). In-frame duplications in the pleckstrin-homology domain (PHD) of the protein were found in more than 60% of JGCTs occurring in girls under 15 years of age. The JGCTs without duplications carried point mutations affecting highly conserved residues. The mutated proteins carrying the duplications displayed a non-wild-type subcellular distribution, with a marked enrichment at the plasma membrane. This led to a striking degree of AKT1 activation demonstrated by a strong phosphorylation level and corroborated by reporter assays. [38]

Analysis by RNA-Seq pinpointed a series of differentially expressed genes, involved in cytokine and hormone signaling and cell division-related processes. Further analyses pointed to a possible dedifferentiation process and suggested that most of the transcriptomic dysregulations might be mediated by a limited set of transcription factors perturbed by AKT1 activation. These results incriminate somatic mutations of AKT1 as major probably driver events in the pathogenesis of JGCTs. [39]

See also

Related Research Articles

Phosphatidylinositol (3,4,5)-trisphosphate chemical compound

Phosphatidylinositol (3,4,5)-trisphosphate (PtdIns(3,4,5)P3), abbreviated PIP3, is the product of the class I phosphoinositide 3-kinases (PI 3-kinases) phosphorylation of phosphatidylinositol (4,5)-bisphosphate (PIP2). It is a phospholipid that resides on the plasma membrane.

Phosphoinositide 3-kinase enzyme

Phosphoinositide 3-kinases (PI3Ks), also called phosphatidylinositol 3-kinases, are a family of enzymes involved in cellular functions such as cell growth, proliferation, differentiation, motility, survival and intracellular trafficking, which in turn are involved in cancer.

The MAPK/ERK pathway is a chain of proteins in the cell that communicates a signal from a receptor on the surface of the cell to the DNA in the nucleus of the cell.

Platelet-derived growth factor receptor

Platelet-derived growth factor receptors (PDGF-R) are cell surface tyrosine kinase receptors for members of the platelet-derived growth factor (PDGF) family. PDGF subunits -A and -B are important factors regulating cell proliferation, cellular differentiation, cell growth, development and many diseases including cancer. There are two forms of the PDGF-R, alpha and beta each encoded by a different gene. Depending on which growth factor is bound, PDGF-R homo- or heterodimerizes.

The PHLPP isoforms are a pair of protein phosphatases, PHLPP1 and PHLPP2, that are important regulators of Akt serine-threonine kinases and conventional/novel protein kinase C (PKC) isoforms. PHLPP may act as a tumor suppressor in several types of cancer due to its ability to block growth factor-induced signaling in cancer cells.

The ErbB family of proteins contains four receptor tyrosine kinases, structurally related to the epidermal growth factor receptor (EGFR), its first discovered member. In humans, the family includes Her1, Her2, Her3 (ErbB3), and Her4 (ErbB4). The gene symbol, ErbB, is derived from the name of a viral oncogene to which these receptors are homologous: erythroblastic leukemia viral oncogene. Insufficient ErbB signaling in humans is associated with the development of neurodegenerative diseases, such as multiple sclerosis and Alzheimer's Disease, while excessive ErbB signaling is associated with the development of a wide variety of types of solid tumor.

AKT1 protein-coding gene in the species Homo sapiens

RAC-alpha serine/threonine-protein kinase is an enzyme that in humans is encoded by the AKT1 gene. This enzyme belongs to the AKT subfamily of serine/threonine kinases that contain SH2 domains. It is commonly referred to as PKB, or by both names as "Akt/PKB".

IRS1 protein-coding gene in the species Homo sapiens

Insulin receptor substrate 1 (IRS-1) is a signaling adapter protein that in humans is encoded by the IRS-1 gene. It is a 131 kDa protein with amino acid sequence of 1242 residues. It contains a single pleckstrin homology (PH) domain at the N-terminus and a PTB domain ca. 40 residues downstream of this, followed by a poorly conserved C-terminus tail. Together with IRS2, IRS3 (pseudogene) and IRS4, it is homologous to the Drosophila protein chico, whose disruption extends the median lifespan of flies up to 48%. Similarly, Irs1 mutant mice experience moderate life extension and delayed age-related pathologies.

AKT2 protein-coding gene in the species Homo sapiens

RAC-beta serine/threonine-protein kinase is an enzyme that in humans is encoded by the AKT2 gene.

TNK2 protein-coding gene in the species Homo sapiens

Activated CDC42 kinase 1, also known as ACK1, is an enzyme that in humans is encoded by the TNK2 gene.

RPTOR protein-coding gene in the species Homo sapiens

Regulatory-associated protein of mTOR also known as raptor or KIAA1303 is an adapter protein that is encoded in humans by the RPTOR gene. Two mRNAs from the gene have been identified that encode proteins of 1335 and 1177 amino acids long.

The Akt Pathway, or PI3K-Akt Pathway is a signal transduction pathway that promotes survival and growth in response to extracellular signals. Key proteins involved are PI3K and Akt.

Phosphoinositide-dependent kinase-1 protein-coding gene in the species Homo sapiens

In the field of biochemistry, PDPK1 refers to the protein 3-phosphoinositide-dependent protein kinase-1, an enzyme which is encoded by the PDPK1 gene in humans. It is implicated in the development and progression of melanomas.

FOXO1 protein-coding gene in the species Homo sapiens

Forkhead box protein O1 (FOXO1) also known as forkhead in rhabdomyosarcoma is a protein that in humans is encoded by the FOXO1 gene. FOXO1 is a transcription factor that plays important roles in regulation of gluconeogenesis and glycogenolysis by insulin signaling, and is also central to the decision for a preadipocyte to commit to adipogenesis. It is primarily regulated through phosphorylation on multiple residues; its transcriptional activity is dependent on its phosphorylation state.

Tuberous sclerosis proteins 1 and 2, also known as TSC1 (hamartin) and TSC2 (tuberin), form a protein-complex. The encoding two genes are TSC1 and TSC2. The complex is known as a tumor suppressor. Mutations in these genes can cause tuberous sclerosis complex. Depending on the grade of the disease, mental retardation, epilepsy and tumors of the skin, retina, heart, kidney and the central nervous system can be symptoms.

PI3K/AKT/mTOR pathway

The PI3K/AKT/mTOR pathway is an intracellular signaling pathway important in regulating the cell cycle. Therefore, it is directly related to cellular quiescence, proliferation, cancer, and longevity. PI3K activation phosphorylates and activates AKT, localizing it in the plasma membrane. AKT can have a number of downstream effects such as activating CREB, inhibiting p27, localizing FOXO in the cytoplasm, activating PtdIns-3ps, and activating mTOR which can affect transcription of p70 or 4EBP1. There are many known factors that enhance the PI3K/AKT pathway including EGF, shh, IGF-1, insulin, and CaM. The pathway is antagonized by various factors including PTEN, GSK3B, and HB9. In many cancers, this pathway is overactive, thus reducing apoptosis and allowing proliferation. This pathway is necessary, however, to promote growth and proliferation over differentiation of adult stem cells, neural stem cells specifically. It is the difficulty in finding an appropriate amount of proliferation versus differentiation that researchers are trying to determine in order to utilize this balance in the development of various therapies. Additionally, this pathway has been found to be a necessary component in neural long term potentiation.

mTOR inhibitors class of pharmaceutical drugs

mTOR inhibitors are a class of drugs that inhibit the mammalian target of rapamycin (mTOR), which is a serine/threonine-specific protein kinase that belongs to the family of phosphatidylinositol-3 kinase (PI3K) related kinases (PIKKs). mTOR regulates cellular metabolism, growth, and proliferation by forming and signaling through two protein complexes, mTORC1 and mTORC2. The most established mTOR inhibitors are so-called rapalogs, which have shown tumor responses in clinical trials against various tumor types.

mTORC1

mTORC1, also known as mammalian target of rapamycin complex 1 or mechanistic target of rapamycin complex 1, is a protein complex that functions as a nutrient/energy/redox sensor and controls protein synthesis.

mTOR Complex 2 (mTORC2) is a protein complex that regulates cellular metabolism as well as the cytoskeleton. It is defined by the interaction of mTOR and the rapamycin-insensitive companion of mTOR (RICTOR), and also includes GβL, mammalian stress-activated protein kinase interacting protein 1 (mSIN1), as well as Protor 1/2, DEPTOR, and TTI1 and TEL2.

Triciribine chemical compound

Triciribine is a cancer drug which was first synthesized in the 1970s and studied clinically in the 1980s and 1990s without success. Following the discovery in the early 2000s that the drug would be effective against tumours with hyperactivated Akt, it is now again under consideration in a variety of cancers. As PTX-200, the drug is currently in two early stage clinical trials in breast cancer and ovarian cancer being conducted by the small molecule drug development company Prescient Therapeutics.

References

  1. PDB: 3MV5 ; Freeman-Cook KD, Autry C, Borzillo G, Gordon D, Barbacci-Tobin E, Bernardo V, Briere D, Clark T, Corbett M, Jakubczak J, Kakar S, Knauth E, Lippa B, Luzzio MJ, Mansour M, Martinelli G, Marx M, Nelson K, Pandit J, Rajamohan F, Robinson S, Subramanyam C, Wei L, Wythes M, Morris J (June 2010). "Design of selective, ATP-competitive inhibitors of Akt". J. Med. Chem. 53 (12): 4615–22. doi:10.1021/jm1003842. PMID   20481595.
  2. PDB: 3D0E ; Heerding DA, Rhodes N, Leber JD, Clark TJ, Keenan RM, Lafrance LV, Li M, Safonov IG, Takata DT, Venslavsky JW, Yamashita DS, Choudhry AE, Copeland RA, Lai Z, Schaber MD, Tummino PJ, Strum SL, Wood ER, Duckett DR, Eberwein D, Knick VB, Lansing TJ, McConnell RT, Zhang S, Minthorn EA, Concha NO, Warren GL, Kumar R (September 2008). "Identification of 4-(2-(4-amino-1,2,5-oxadiazol-3-yl)-1-ethyl-7-{[(3S)-3-piperidinylmethyl]oxy}-1H-imidazo[4,5-c]pyridin-4-yl)-2-methyl-3-butyn-2-ol (GSK690693), a novel inhibitor of AKT kinase". J. Med. Chem. 51 (18): 5663–79. doi:10.1021/jm8004527. PMID   18800763.
  3. Chen WS, Xu PZ, Gottlob K, Chen ML, Sokol K, Shiyanova T, Roninson I, Weng W, Suzuki R, Tobe K, Kadowaki T, Hay N (September 2001). "Growth retardation and increased apoptosis in mice with homozygous disruption of the Akt1 gene". Genes & Development. 15 (17): 2203–2208. doi:10.1101/gad.913901. PMC   312770 . PMID   11544177.
  4. Staal SP, Hartley JW, Rowe WP (July 1977). "Isolation of transforming murine leukemia viruses from mice with a high incidence of spontaneous lymphoma". Proc. Natl. Acad. Sci. U.S.A. 74 (7): 3065–7. doi:10.1073/pnas.74.7.3065. PMC   431413 . PMID   197531.
  5. Garofalo RS, Orena SJ, Rafidi K, Torchia AJ, Stock JL, Hildebrandt AL, Coskran T, Black SC, Brees DJ, Wicks JR, McNeish JD, Coleman KG (July 2003). "Severe diabetes, age-dependent loss of adipose tissue, and mild growth deficiency in mice lacking Akt2/PKB beta". J. Clin. Invest. 112 (2): 197–208. doi:10.1172/JCI16885. PMC   164287 . PMID   12843127.
  6. Hill MM, Hemmings BA (2002). "Inhibition of protein kinase B/Akt. implications for cancer therapy". Pharmacol. Ther. 93 (2–3): 243–51. doi:10.1016/S0163-7258(02)00193-6. PMID   12191616.
  7. Mitsiades CS, Mitsiades N, Koutsilieris M (2004). "The Akt pathway: molecular targets for anti-cancer drug development". Curr Cancer Drug Targets. 4 (3): 235–56. doi:10.2174/1568009043333032. PMID   15134532.
  8. Yang ZZ, Tschopp O, Baudry A, Dümmler B, Hynx D, Hemmings BA (April 2004). "Physiological functions of protein kinase B/Akt". Biochem. Soc. Trans. 32 (Pt 2): 350–4. doi:10.1042/BST0320350. PMID   15046607.
  9. Franke TF, Kaplan DR, Cantley LC, Toker A (January 1997). "Direct regulation of the Akt proto-oncogene product by phosphatidylinositol-3,4-bisphosphate". Science. 275 (5300): 665–8. doi:10.1126/science.275.5300.665. PMID   9005852.
  10. Sarbassov DD, Guertin DA, Ali SM, Sabatini DM (February 2005). "Phosphorylation and regulation of Akt/PKB by the rictor-mTOR complex". Science. 307 (5712): 1098–101. doi:10.1126/science.1106148. PMID   15718470.
  11. Jacinto E, Facchinetti V, Liu D, Soto N, Wei S, Jung SY, Huang Q, Qin J, Su B (October 2006). "SIN1/MIP1 maintains rictor-mTOR complex integrity and regulates Akt phosphorylation and substrate specificity". Cell. 127 (1): 125–37. doi:10.1016/j.cell.2006.08.033. PMID   16962653.
  12. 1 2 Mahajan K, Coppola D, Challa S, Fang B, Chen YA, Zhu W, Lopez AS, Koomen J, Engelman RW, Rivera C, Muraoka-Cook RS, Cheng JQ, Schönbrunn E, Sebti SM, Earp HS, Mahajan NP (March 2010). "Ack1 mediated AKT/PKB tyrosine 176 phosphorylation regulates its activation". PLoS ONE. 5 (3): e9646. doi:10.1371/journal.pone.0009646. PMC   2841635 . PMID   20333297.
  13. Stuenaes JT, Bolling A, Ingvaldsen A, Rommundstad C, Sudar E, Lin FC, Lai YC, Jensen J (May 2010). "Beta-adrenoceptor stimulation potentiates insulin-stimulated PKB phosphorylation in rat cardiomyocytes via cAMP and PKA". Br. J. Pharmacol. 160 (1): 116–29. doi:10.1111/j.1476-5381.2010.00677.x. PMC   2860212 . PMID   20412069.
  14. Fan CD, Lum MA, Xu C, Black JD, Wang X (November 2012). "Ubiquitin-dependent regulation of phospho-AKT dynamics by the ubiquitin E3 ligase, NEDD4-1, in the IGF-1 response". J. Biol. Chem. 288 (3): 1674–84. doi:10.1074/jbc.M112.416339. PMC   3548477 . PMID   23195959.
  15. Cooper, Geoffrey M. (2000). "Figure 15.37: PTEN and PI3K". The cell: a molecular approach. Washington, D.C: ASM Press. ISBN   978-0-87893-106-4.
  16. Song G, Ouyang G, Bao S (2005). "The activation of Akt/PKB signaling pathway and cell survival". J. Cell. Mol. Med. 9 (1): 59–71. doi:10.1111/j.1582-4934.2005.tb00337.x. PMID   15784165.
  17. Alberts B, Johnson A, Lewis J, Raff M, Roberts K, Walter P (2002). "Figure 15-60: BAD phosphorylation by Akt". Molecular biology of the cell. New York: Garland Science. ISBN   978-0-8153-3218-3.
  18. Lodish H, Berk A, Zipursky LS, Matsudaira P, Baltimore D, Darnell J (1999). "Figure 23-50: BAD interaction with Bcl-2". Molecular cell biology. New York: Scientific American Books. ISBN   978-0-7167-3136-8.
  19. Faissner A, Heck N, Dobbertin A, Garwood J (2006). DSD-1-Proteoglycan/Phosphacan and receptor protein tyrosine phosphatase-beta isoforms during development and regeneration of neural tissues. Adv. Exp. Med. Biol. Advances in Experimental Medicine and Biology. 557. pp. 25–53, Figure 2: regulation of NF–κB. doi:10.1007/0-387-30128-3_3. ISBN   978-0-306-47859-8. PMID   16955703.
  20. Ramaswamy S, Nakamura N, Vazquez F, Batt DB, Perera S, Roberts TM, Sellers WR (March 1999). "Regulation of G1 progression by the PTEN tumor suppressor protein is linked to inhibition of the phosphatidylinositol 3-kinase/Akt pathway". Proc. Natl. Acad. Sci. U.S.A. 96 (5): 2110–5. doi:10.1073/pnas.96.5.2110. PMC   26745 . PMID   10051603.
  21. Kandel ES, Skeen J, Majewski N, Di Cristofano A, Pandolfi PP, Feliciano CS, Gartel A, Hay N (November 2002). "Activation of Akt/protein kinase B overcomes a G(2)/m cell cycle checkpoint induced by DNA damage". Mol. Cell. Biol. 22 (22): 7831–41. doi:10.1128/MCB.22.22.7831-7841.2002. PMC   134727 . PMID   12391152.
  22. Sardiello M, Palmieri M, di Ronza A, Medina DL, Valenza M, Gennarino VA, Di Malta C, Donaudy F, Embrione V, Polishchuk RS, Banfi S, Parenti G, Cattaneo E, Ballabio A (Jul 2009). "A gene network regulating lysosomal biogenesis and function". Science. 325 (5939): 473–7. doi:10.1126/science.1174447. PMID   19556463.
  23. 1 2 3 Palmieri M, Pal R, Nelvagal HR, Lotfi P, Stinnett GR, Seymour ML, Chaudhury A, Bajaj L, Bondar VV, Bremner L, Saleem U, Tse DY, Sanagasetti D, Wu SM, Neilson JR, Pereira FA, Pautler RG, Rodney GG, Cooper JD, Sardiello M (Feb 2017). "mTORC1-independent TFEB activation via Akt inhibition promotes cellular clearance in neurodegenerative storage diseases". Nature Communications. 8: 14338. doi:10.1038/ncomms14338. PMC   5303831 . PMID   28165011.
  24. Chen J, Somanath PR, Razorenova O, Chen WS, Hay N, Bornstein P, Byzova TV (November 2005). "Akt1 regulates pathological angiogenesis, vascular maturation and permeability in vivo". Nat. Med. 11 (11): 1188–96. doi:10.1038/nm1307. PMC   2277080 . PMID   16227992.
  25. Somanath PR, Razorenova OV, Chen J, Byzova TV (March 2006). "Akt1 in endothelial cell and angiogenesis". Cell Cycle. 5 (5): 512–8. doi:10.4161/cc.5.5.2538. PMC   1569947 . PMID   16552185.
  26. "Tumor Genetics; AKT Function and Oncogenic Activity" (PDF). Scientific Report. Fox Chase Cancer Center. 2005.
  27. Lindhurst MJ, Sapp JC, Teer JK, Johnston JJ, Finn EM, Peters K, Turner J, Cannons JL, Bick D, Blakemore L, Blumhorst C, Brockmann K, Calder P, Cherman N, Deardorff MA, Everman DB, Golas G, Greenstein RM, Kato BM, Keppler-Noreuil KM, Kuznetsov SA, Miyamoto RT, Newman K, Ng D, O'Brien K, Rothenberg S, Schwartzentruber DJ, Singhal V, Tirabosco R, Upton J, Wientroub S, Zackai EH, Hoag K, Whitewood-Neal T, Robey PG, Schwartzberg PL, Darling TN, Tosi LL, Mullikin JC, Biesecker LG (August 2011). "A mosaic activating mutation in AKT1 associated with the Proteus syndrome". N. Engl. J. Med. 365 (7): 611–9. doi:10.1056/NEJMoa1104017. PMC   3170413 . PMID   21793738.
  28. "VioQuest Pharmaceuticals Announces Phase I/IIa Trial For Akt Inhibitor VQD-002". Apr 2007.
  29. Ghobrial IM, Roccaro A, Hong F, Weller E, Rubin N, Leduc R, Rourke M, Chuma S, Sacco A, Jia X, Azab F, Azab AK, Rodig S, Warren D, Harris B, Varticovski L, Sportelli P, Leleu X, Anderson KC, Richardson PG (February 2010). "Clinical and translational studies of a phase II trial of the novel oral Akt inhibitor perifosine in relapsed or relapsed/refractory Waldenstrom's macroglobulinemia". Clin. Cancer Res. 16 (3): 1033–41. doi:10.1158/1078-0432.CCR-09-1837. PMC   2885252 . PMID   20103671.
  30. Cheshenko N, Trepanier JB, Stefanidou M, Buckley N, Gonzalez P, Jacobs W, Herold BC (March 2013). "HSV activates Akt to trigger calcium release and promote viral entry: novel candidate target for treatment and suppression". FASEB J. 27 (7): 2584–99. doi:10.1096/fj.12-220285. PMC   3688744 . PMID   23507869. Lay summary Sci-News.
  31. Yap TA, Yan L, Patnaik A, Fearen I, Olmos D, Papadopoulos K, Baird RD, Delgado L, Taylor A, Lupinacci L, Riisnaes R, Pope LL, Heaton SP, Thomas G, Garrett MD, Sullivan DM, de Bono JS, Tolcher AW (2011). "First-in-man clinical trial of the oral pan-AKT inhibitor MK-2206 in patients with advanced solid tumors". J Clin Oncol. 29 (35): 4688–95. doi:10.1200/JCO.2011.35.5263. PMID   22025163.
  32. MK-2206 phase-2 trials
  33. AKT inhibitor AZD5363 well tolerated, yielded partial response in patients with advanced solid tumors
  34. PARP/AKT Inhibitor Combination Active in Multiple Tumor Types. April 2016
  35. The inhibitor is derived from the Human Genome, 5'- ATGGACCAAAGAGTTTCAGGGA-3' and is available under open access for all scientists to use.
  36. Ipatasertib plus paclitaxel versus placebo plus paclitaxel as first-line therapy for metastatic triple-negative breast cancer (LOTUS): a multicentre, randomised, double-blind, placebo-controlled, phase 2 trial. 2017
  37. Sykes SM, Lane SW, Bullinger L, Kalaitzidis D, Yusuf R, Saez B, Ferraro F, Mercier F, Singh H, Brumme KM, Acharya SS, Scholl C, Schöll C, Tothova Z, Attar EC, Fröhling S, DePinho RA, Armstrong SA, Gilliland DG, Scadden DT (September 2011). "AKT/FOXO signaling enforces reversible differentiation blockade in myeloid leukemias". Cell. 146 (5): 697–708. doi:10.1016/j.cell.2011.07.032. PMC   3826540 . PMID   21884932.
  38. Bessière L, Todeschini AL, Auguste A, Sarnacki S, Flatters D, Legois B, Sultan C, Kalfa N, Galmiche L, Veitia RA (March 2015). "A Hot-spot of In-frame Duplications Activates the Oncoprotein AKT1 in Juvenile Granulosa Cell Tumors". EBioMedicine. 2 (5): 421–31. doi:10.1016/j.ebiom.2015.03.002. PMC   4485906 . PMID   26137586.
  39. Auguste A, Bessière L, Todeschini AL, Caburet S, Sarnacki S, Prat J, D'angelo E, De La Grange P, Ariste O, Lemoine F, Legois B, Sultan C, Zider A, Galmiche L, Kalfa N, Veitia RA (Dec 2015). "Molecular analyses of juvenile granulosa cell tumors bearing AKT1 mutations provide insights into tumor biology and therapeutic leads". Hum Mol Genet. 24 (23): 6687–98. doi:10.1093/hmg/ddv373. PMID   26362254.

Further reading