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"In vivo 32P labeling and mutagenesis demonstrated that m/p-PKBalpha activity was due to phosphorylation on Thr308 and Ser473, that are normally induced on PKB following stimulation of the cells with insulin or insulin-like growth factor-1 (IGF-1).... Following activation the kinase detached from the membrane and translocated to the nucleus."

"Thrombin induces the activation of platelet serine/threonine kinase Akt. Akt activation is dependent on its phosphorylation at threonine 308 and serine 473. "

"Fig. 1. Insulin-like growth factor 1 (IGF-1)-mediated signaling pathways relevant to hypertrophy. Binding of IGF-1 activates the IGF-1 receptor (purple), which then recruits insulin-receptor substrate (IRS-1). This leads to the activation of two signaling pathways: the Ras-Raf-MEK-ERK pathway and the phosphatidylinositol 3-kinase (PI3K)- Akt pathway. The PI3K-Akt pathway recapitulates hypertrophy caused by IGF-1 stimulation. Akt1 activity can be modulated either by directly controlling its phosphorylation state or by altering the levels of the lipid that it binds at the cell membrane, phosphatidylinositol (3,4,5)-trisphosphate [PtdIns(3,4,5)P3] (orange). Signaling molecules that have been shown to have a negative effect on hypertrophy are colored red, and proteins whose activation induces hypertrophy are shown in green. Proteins that have not been assayed for their role in hypertrophy are shown in blue. Abbreviations: eIF-2B, eukaryotic translation initiation factor 2B; ERK, extracellular-signal-regulated kinase; GSK3b, glycogen-synthase kinase 3b; mTOR, mammalian target of rapamycin; p70S6K, p70 S6 kinase; PDK, phosphoinositide-dependent protein kinase; PtdIns(3,4)P2, phosphatidylinositol (3,4)-bisphosphate; PtdIns(4,5)P2, phosphatidylinositol (4,5)-bisphosphate; PHAS-1, phosphorylated heat- and acid-stable protein 1; PP2A, protein phosphatase 2A; PTEN, phosphatase and tensin homologous on chromosome 10; SHIP2, SH2-domain-containing inositol phosphatase; Tsc1/2, tuberous sclerosis complex 1 and 2. Modified from Ref. [87]. Akt1 activity can be modulated either by directly controlling its phosphorylation state or by altering the levels of the lipid that it binds at the cell membrane, PtdIns(3,4,5)P3 [22] (Fig. 1). Akt1 activity depends on phosphorylation at two sites: Ser473 and Thr309 [29]."

"Activation of PKB alpha and beta is then achieved at the plasma membrane by phosphorylation of Thr308/309 in the A-loop of the kinase domain and Ser473/474 in the carboxy-terminal regulatory region, respectively. The upstream kinase that phosphorylates PKB on Thr308, termed PI-dependent protein kinase-1, has been identified and extensively characterised. A candidate for the Ser473/474 kinase, termed the integrin-linked kinase, has been identified recently."

"Stimulation of platelets with a PAR1-activating peptide (SFLLRN), PAR4-activating peptide (AYPGKF), and thrombin resulted in Thr308 and Ser473 phosphorylation of Akt, which results in its activation."

"As shown in Fig. 2 B, subconfluent HeLa cultures have relatively low levels of active PKB, as detected by antibodies specifically recognizing PKB phosphorylated on serine 473. Phosphorylation of PKB is fully inhibitable by treatment with the specific PI 3-kinase inhibitor LY294002. Sparse cultures have barely detectable levels of phosphorylated PKB; however, dense cultures have much more activated PKB, whereas the total levels of PKB protein remain constant under all conditions examined."

"Furthermore, we show that inhibition of mTOR by rapamycin induces the activation of Akt as shown by increased Akt phosphorylation at Ser(473) and the inhibition of 6-TG-induced apoptosis and cell death. Activated Akt is a well-known inhibitor of autophagy."

"three isoforms, AKT1 (PKBalpha), AKT2 (PKBbeta) and AKT3 (PKBgamma) they all contain a central kinase domain with an activation-loop phosphorylation site, Thr308, and a conserved, regulatory C-terminal phosphorylation site, Ser473"

"mTORC2 can be activated by PI3K directly and phosphorylates Akt at S473, which together with phosphorylation at T308 results in the full activation of Akt [12,13]."

"Upon stimulation with insulin, AKT is recruited to cellular membranes by binding of its amino terminal pleckstrin (PH) domain to membrane bound phosphatidylinositol 3,4,5, trisphosphate (PIP3) [3]. The membrane bound form of AKT then becomes phosphorylated on two regulatory residues, a threonine within the activation loop (Thr308 in AKT1,Thr309 in AKT2, Thr305 in AKT3) and a serine in the C-terminus of the enzyme (Ser473 in AKT1,Ser474 in AKT2, Ser472 in AKT3), and both phosphorylations are considered to be required for AKT to reach maximum kinase activity [1]. The kinase responsible for phosphorylation of Thr308/309/305 has been identified as phosphoinositide-dependent kinase 1 (PDK1) [3]."

"Thrombin induces the activation of platelet serine/threonine kinase Akt. Akt activation is dependent on its phosphorylation at threonine 308 and serine 473."

"Furthermore, we show that inhibition of mTOR by rapamycin induces the activation of Akt as shown by increased Akt phosphorylation at Ser(473) and the inhibition of 6-TG-induced apoptosis and cell death. Activated Akt is a well-known inhibitor of autophagy. "

"Phosphorylation at Ser473 in the hydrophobic motif, along with Thr308 in its activation loop, is considered necessary for Akt function."

"The impact of IL-8 binding to AAT or HSA on its ability to stimulate Akt Ser473 phosphorylation, a key step in IL-8? mediated neutrophil chemotaxis (27), was explored. Figure 7D shows that IL-8 (1 ng) stimulated adequate Akt phosphorylation after just 10 minutes and that this effect was unaffected by prebinding of IL-8 to HSA (27.5 uM)."

"Akt becomes activated upon phosphorylation of Ser473 and Thr308. In the absence of insulin, dexamethasone reduced Ser473 phosphorylation by 33% (P < 0.05 vs. no treatment, n = 3)."

"Overexpressed IRS-3 as well as IRS-1 enhanced phosphoinositide (PI) 3-kinase activity in response to insulin and increased phosphorylation of protein kinase B (PKB) at S473 and phosphorylation of one of the members of the forkhead transcription factor FKHRL1 on T32 in both insulin-untreated and -treated states."

"Fig. 1. Insulin-like growth factor 1 (IGF-1)-mediated signaling pathways relevant to hypertrophy. Binding of IGF-1 activates the IGF-1 receptor (purple), which then recruits insulin-receptor substrate (IRS-1). This leads to the activation of two signaling pathways: the Ras-Raf-MEK-ERK pathway and the phosphatidylinositol 3-kinase (PI3K)- Akt pathway. The PI3K-Akt pathway recapitulates hypertrophy caused by IGF-1 stimulation. Akt1 activity can be modulated either by directly controlling its phosphorylation state or by altering the levels of the lipid that it binds at the cell membrane, phosphatidylinositol (3,4,5)-trisphosphate [PtdIns(3,4,5)P3] (orange). Signaling molecules that have been shown to have a negative effect on hypertrophy are colored red, and proteins whose activation induces hypertrophy are shown in green. Proteins that have not been assayed for their role in hypertrophy are shown in blue. Abbreviations: eIF-2B, eukaryotic translation initiation factor 2B; ERK, extracellular-signal-regulated kinase; GSK3b, glycogen-synthase kinase 3b; mTOR, mammalian target of rapamycin; p70S6K, p70 S6 kinase; PDK, phosphoinositide-dependent protein kinase; PtdIns(3,4)P2, phosphatidylinositol (3,4)-bisphosphate; PtdIns(4,5)P2, phosphatidylinositol (4,5)-bisphosphate; PHAS-1, phosphorylated heat- and acid-stable protein 1; PP2A, protein phosphatase 2A; PTEN, phosphatase and tensin homologous on chromosome 10; SHIP2, SH2-domain-containing inositol phosphatase; Tsc1/2, tuberous sclerosis complex 1 and 2. Modified from Ref. [87]. Akt1 activity can be modulated either by directly controlling its phosphorylation state or by altering the levels of the lipid that it binds at the cell membrane, PtdIns(3,4,5)P3 [22] (Fig. 1). Akt1 activity depends on phosphorylation at two sites: Ser473 and Thr309 [29]."

"three isoforms, AKT1 (PKBalpha), AKT2 (PKBbeta) and AKT3 (PKBgamma) they all contain a central kinase domain with an activation-loop phosphorylation site, Thr308, and a conserved, regulatory C-terminal phosphorylation site, Ser473"

"Phosphorylation at Ser473 in the hydrophobic motif, along with Thr308 in its activation loop, is considered necessary for Akt function."

"IL-4 induces PI-3K activity, as shown by Western blotting analysis, demonstrating the specific phosphorylation of PKB, a downstream substrate of PI-3K, at residues Ser473 and Thr308."

"As shown in Fig. 2 B, subconfluent HeLa cultures have relatively low levels of active PKB, as detected by antibodies specifically recognizing PKB phosphorylated on serine 473. Phosphorylation of PKB is fully inhibitable by treatment with the specific PI 3-kinase inhibitor LY294002. Sparse cultures have barely detectable levels of phosphorylated PKB; however, dense cultures have much more activated PKB, whereas the total levels of PKB protein remain constant under all conditions examined."

"Overexpressed IRS-3 as well as IRS-1 enhanced phosphoinositide (PI) 3-kinase activity in response to insulin and increased phosphorylation of protein kinase B (PKB) at S473 and phosphorylation of one of the members of the forkhead transcription factor FKHRL1 on T32 in both insulin-untreated and -treated states."

"In vivo 32P labeling and mutagenesis demonstrated that m/p-PKBalpha activity was due to phosphorylation on Thr308 and Ser473, that are normally induced on PKB following stimulation of the cells with insulin or insulin-like growth factor-1 (IGF-1).... Following activation the kinase detached from the membrane and translocated to the nucleus."

"Akt becomes activated upon phosphorylation of Ser473 and Thr308. In the absence of insulin, dexamethasone reduced Ser473 phosphorylation by 33% (P < 0.05 vs. no treatment, n = 3)."

"In this paper, we present a comprehensive pathway map of EGFR signaling and other related pathways."

"Upon stimulation with insulin, AKT is recruited to cellular membranes by binding of its amino terminal pleckstrin (PH) domain to membrane bound phosphatidylinositol 3,4,5, trisphosphate (PIP3) [3]. The membrane bound form of AKT then becomes phosphorylated on two regulatory residues, a threonine within the activation loop (Thr308 in AKT1,Thr309 in AKT2, Thr305 in AKT3) and a serine in the C-terminus of the enzyme (Ser473 in AKT1,Ser474 in AKT2, Ser472 in AKT3), and both phosphorylations are considered to be required for AKT to reach maximum kinase activity [1]. The kinase responsible for phosphorylation of Thr308/309/305 has been identified as phosphoinositide-dependent kinase 1 (PDK1) [3]."

"Stimulation of platelets with a PAR1-activating peptide (SFLLRN), PAR4-activating peptide (AYPGKF), and thrombin resulted in Thr308 and Ser473 phosphorylation of Akt, which results in its activation."

"After PIP3 binding, Akt1 is activated by phosphorylation on two critical residues, namely threonine %308 (T308) and serine 473 (S473); similar activation residues (S472 and S474, %respectively) are highly conserved in Akt2 and Akt3 Phosphoinositol-3-phosphate (PIP3) is a product of phosphoinositol 3-kinase enzymatic activity and has been shown to be a prerequisite lipid modulator of Akt activity Akt activity can be regulated by the PTEN tumour suppressor gene, which negatively regulates PIP3 levels PIP3 has been described as a downstream component of a wide range of receptors, including the c-Met receptor [5], the epidermal growth factor receptor family [6], fibroblast growth factor receptor [7], insulin growth factor receptor [8] and platelet-derived growth factor receptor"

"Furthermore, serum starvation-induced apoptosis caused a twofold increase in caspase 3 activity in C1-TEN-overexpressing cells vs. mock cells. In addition, C1-TEN-overexpressing cells showed a markedly reduced phosphorylation of Akt/PKB kinase and its substrate GSK3, as well as reduced Akt enzymatic activity. Equal amounts of total cell lysates were subjected to 10% SDSPAGE. The membrane was then probed with polyclonal antibody against GSK3 specifically phosphorylated at Ser21/9 (pGSK3?/?, CST), after which the membrane was stripped (stripping buffer, Pierce) and reprobed with polyclonal anti-total Akt antibody (CST). and Western blotting for detection of either Akt kinase specifically phosphorylated at Ser473 (pAkt) or both 42 and 44 kDa isoforms of phosphorylated ERK (pERK) using specific antibodies (Santa Cruz Biotechnology, Santa Cruz, CA)."

"After PIP3 binding, Akt1 is activated by phosphorylation on two critical residues, namely threonine %308 (T308) and serine 473 (S473); similar activation residues (S472 and S474, %respectively) are highly conserved in Akt2 and Akt3 Phosphoinositol-3-phosphate (PIP3) is a product of phosphoinositol 3-kinase enzymatic activity and has been shown to be a prerequisite lipid modulator of Akt activity Akt activity can be regulated by the PTEN tumour suppressor gene, which negatively regulates PIP3 levels PIP3 has been described as a downstream component of a wide range of receptors, including the c-Met receptor [5], the epidermal growth factor receptor family [6], fibroblast growth factor receptor [7], insulin growth factor receptor [8] and platelet-derived growth factor receptor"

"The impact of IL-8 binding to AAT or HSA on its ability to stimulate Akt Ser473 phosphorylation, a key step in IL-8? mediated neutrophil chemotaxis (27), was explored. Figure 7D shows that IL-8 (1 ng) stimulated adequate Akt phosphorylation after just 10 minutes and that this effect was unaffected by prebinding of IL-8 to HSA (27.5 uM)."

"Furthermore, serum starvation-induced apoptosis caused a twofold increase in caspase 3 activity in C1-TEN-overexpressing cells vs. mock cells. In addition, C1-TEN-overexpressing cells showed a markedly reduced phosphorylation of Akt/PKB kinase and its substrate GSK3, as well as reduced Akt enzymatic activity. Equal amounts of total cell lysates were subjected to 10% SDSPAGE. The membrane was then probed with polyclonal antibody against GSK3 specifically phosphorylated at Ser21/9 (pGSK3?/?, CST), after which the membrane was stripped (stripping buffer, Pierce) and reprobed with polyclonal anti-total Akt antibody (CST). and Western blotting for detection of either Akt kinase specifically phosphorylated at Ser473 (pAkt) or both 42 and 44 kDa isoforms of phosphorylated ERK (pERK) using specific antibodies (Santa Cruz Biotechnology, Santa Cruz, CA)."

"Activation of PKB alpha and beta is then achieved at the plasma membrane by phosphorylation of Thr308/309 in the A-loop of the kinase domain and Ser473/474 in the carboxy-terminal regulatory region, respectively. The upstream kinase that phosphorylates PKB on Thr308, termed PI-dependent protein kinase-1, has been identified and extensively characterised. A candidate for the Ser473/474 kinase, termed the integrin-linked kinase, has been identified recently."