Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.56316212 |
Taken together , we conclude that PKCzeta can regulate AMPK activity by increasing the Ser 428 phosphorylation of LKB 1 , resulting in association of LKB 1 with AMPK and consequent AMPK Thr 172 phosphorylation by LKB1 . . 0.56316212^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
We further show that the closely related mammalian LKB 1 kinase , which is associated with Peutz Jeghers cancer susceptibility syndrome , phosphorylates and activates AMPK in vitro . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
Second , both endogenous and recombinant complexes of LKB 1 , STRAD alpha / beta and MO 25 alpha / beta activate AMPK via phosphorylation of Thr 172 . ^^^ Fourth , the AMPK activating drugs AICA riboside and phenformin do not activate AMPK in HeLa cells ( which lack LKB 1 ) , but activation can be restored by stably expressing wild type , but not catalytically inactive , LKB 1 . ^^^ Fifth , AICA riboside and phenformin fail to activate AMPK in immortalized fibroblasts from LKB 1 knockout mouse embryos . ^^^ CONCLUSIONS : These results provide the first description of a physiological substrate for the LKB 1 tumor suppressor and suggest that it functions as an upstream regulator of AMPK . ^^^ Our findings indicate that the tumors in Peutz Jeghers syndrome could result from deficient activation of AMPK as a consequence of LKB 1 inactivation . . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
LKB 1 shares sequence similarity with Elm 1 , Pak 1 , and Tos 3 , and we demonstrated that LKB 1 phosphorylates AMPK on the activation loop threonine ( Thr 172 ) within the catalytic subunit and activates AMPK in vitro [ 9 ] . ^^^ AMPKK purified from rat liver corresponds to LKB 1 , and blocking LKB 1 activity in cells abolishes AMPK activation in response to different stimuli . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
Recent findings have identified LKB 1 a protein kinase that is mutated in a hereditary form of cancer as a candidate for the upstream kinase in the AMPK cascade . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
LKB 1 is a master kinase that activates 13 kinases of the AMPK subfamily , including MARK / PAR 1 . ^^^ We recently demonstrated that the LKB 1 tumour suppressor kinase , in complex with the pseudokinase STRAD and the scaffolding protein MO 25 , phosphorylates and activates AMP activated protein kinase ( AMPK ) . ^^^ Mutation of the T loop Thr phosphorylated by LKB 1 to Ala prevented activation , while mutation to glutamate produced active forms of many of the AMPK related kinases . ^^^ Neither LKB 1 activity nor that of AMPK related kinases was stimulated by phenformin or AICAR , which activate AMPK . ^^^ Our results show that LKB 1 functions as a master upstream protein kinase , regulating AMPK related kinases as well as AMPK . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
Here we present biochemical and genetic evidence indicating that the LKB 1 serine / threonine kinase , the gene inactivated in the Peutz Jeghers familial cancer syndrome , is the dominant regulator of AMPK activation in several mammalian cell types . ^^^ LKB 1 deficient murine embryonic fibroblasts show nearly complete loss of Thr 172 phosphorylation and downstream AMPK signaling in response to a variety of stimuli that activate AMPK . ^^^ Reintroduction of WT , but not kinase dead , LKB 1 into these cells restores AMPK activity . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
Furthermore , we show that LKB 1 activates TSC 2 through the AMP dependent protein kinase ( AMPK ) , indicating that LKB 1 plays a role in cell growth regulation in response to cellular energy levels . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
In addition , metformin significantly increased the co immunoprecipitation of AMPK and its upstream kinase , LKB 1 , in C57BL6 mice administered to metformin in vivo . ^^^ We conclude that activation of AMPK by metformin might be mediated by mitochondria derived RNS , and activation of the c Src / PI3K pathway might generate a metabolite or other molecule inside the cell to promote AMPK activation by the LKB 1 complex . . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
Neither the Thr 172 phosphorylating protein kinase LKB 1 nor the Thr 172 dephosphorylating PP , PP2C , were mobility shifted after treatment with toxins or AICAR , whereas a slight mobility shifting of the regulatory AMPK beta subunit was indicated . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
IGF 1 phosphorylates AMPK alpha subunit in ATM dependent and LKB 1 independent manner . ^^^ Interestingly , even an LKB 1 nonexpressing cancer cell line , HeLa , exhibited growth factor stimulated AMPK alpha subunit phosphorylation , suggesting the presence of an LKB 1 independent pathway for AMPK alpha subunit phosphorylation . ^^^ These results suggest that IGF 1 induces AMPK alpha subunit phosphorylation via an ATM dependent and LKB 1 independent pathway . . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
The repression was associated with the activation of protein kinase A and enhanced phosphorylation of LKB 1 and the AMP activated protein kinase ( AMPK ) . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
Although AMPK phosphorylation was increased by severe ischemia , the protein abundance and activity of the recently identified AMPKK , LKB 1 , were similar between aerobic and severely ischemic hearts . ^^^ In summary , we demonstrate that myocardial ischemia stimulates AMPK via an AMPKK other than LKB 1 . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
AMP binding causes activation by a sensitive mechanism involving phosphorylation of AMPK by the tumour suppressor LKB 1 . ^^^ The LKB 1 > AMPK > TSC 2 pathway negatively regulates the target of rapamycin ( TOR ) , and this appears to be responsible for limiting protein synthesis and cell growth , and protecting against apoptosis , during cellular stresses such as glucose starvation . . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
While energy depletion inhibits mTOR through a process involving the activation of AMP activated protein kinase ( AMPK ) by LKB 1 and subsequent phosphorylation of TSC 2 , the mechanism of mTOR inhibition by hypoxia is not known . ^^^ In contrast to energy depletion , mTOR inhibition by hypoxia does not require AMPK or LKB 1 . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
Recent work indicates that LKB 1 exerts effects on metabolism , polarity and proliferation by phosphorylating and activating protein kinases belonging to the AMPK subfamily . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
We conclude that metabolizable amino acids regulate AMPK in the beta cell via increases in the cytosolic ATP / AMP ratio and via phosphorylation by the upstream kinase LKB 1 . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
LKB 1 , which was recently identified as a direct upstream kinase of AMPK , was not detected in DU 145 cells . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
Thus , it has been demonstrated recently that the tumor suppressor LKB 1 is a kinase that has a major role in phosphorylating and activating AMPK , and that another tumor suppressor , tuberous sclerosis complex 2 , is phosphorylated and activated by AMPK . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
Recent work has shown that the LKB 1 tumour suppressor protein kinase phosphorylates and activates protein kinases belonging to the AMP activated kinase ( AMPK ) subfamily . ^^^ In this study , we identify the sucrose non fermenting protein ( SNF 1 ) related kinase ( SNRK ) , a largely unstudied AMPK subfamily member , as a novel substrate for LKB 1 . ^^^ We also present evidence that two other AMPK related kinases more distantly related to AMPK than SNRK , namely NIM 1 and testis specific serine / threonine kinase 1 ( TSSK 1 ) are not substrates for LKB 1 . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
Reduced activation of AMPK signaling and fatty acid oxidation in obese and obese diabetic myotubes was not associated with reduced protein expression of AMPKalpha and ACCbeta or the expression and activity of the upstream AMPK kinase , LKB 1 . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
New roles for the LKB 1 > AMPK pathway . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
Functional analysis of Peutz Jeghers mutations reveals that the LKB 1 C terminal region exerts a crucial role in regulating both the AMPK pathway and the cell polarity . ^^^ However , these naturally occuring mutations lessened LKB 1 mediated activation of the AMP activated protein kinase ( AMPK ) and impaired downstream signaling . ^^^ Our findings further indicate that LKB 1 tumor suppressor activity is likely to depend on the regulation of AMPK signaling and cell polarization . . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
The only established mammalian AMPK kinase is LKB 1 . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
Deficiency of LKB 1 in skeletal muscle prevents AMPK activation and glucose uptake during contraction . ^^^ Recent studies indicate that the LKB 1 tumour suppressor protein kinase is the major `` upstream ' ' activator of the energy sensor AMP activated protein kinase ( AMPK ) . ^^^ These studies establish the importance of LKB 1 in regulating AMPK activity and cellular energy levels in response to contraction and phenformin . . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
We have employed three cell lines deficient in LKB 1 to study AMPK regulation and phosphorylation , HeLa , A 549 , and murine embryo fibroblasts derived from LKB ( / ) mice . ^^^ Lastly , the activation of AMPK in response to ionomycin and 2 deoxyglucose is not impaired in LKB 1 ( / ) murine embryo fibroblasts . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
AMPK is regulated by upstream kinases of which the tumor suppressor , LKB 1 , is the first to be identified . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
Two upstream kinases have been reported to activate AMPK in cell free assays , i . e . , the tumor suppressor LKB 1 and calmodulin dependent protein kinase kinase . ^^^ We now report that there is a significant basal activity and phosphorylation of AMPK in LKB 1 deficient cells that can be stimulated by Ca2+ ionophores , and studies using the CaMKK inhibitor STO 609 and isoform specific siRNAs show that CaMKKbeta is required for this effect . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
Recently , LKB 1 was shown to activate AMPK . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
This finding suggests that phosphorylation of AMPK by LKB 1 is regulated by allosteric mechanisms . ^^^ The purpose of this study was to determine whether creatine phosphate would inhibit 1 ) phosphorylation of AMPK by LKB 1 and 2 ) AMPK activity after phosphorylation by LKB 1 . ^^^ We found that creatine phosphate did not inhibit phosphorylation of either recombinant or purified rat liver AMPK by LKB 1 . ^^^ In conclusion , these results suggest that creatine phosphate is not a direct regulator of LKB 1 or AMPK activity . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
The LKB 1 tumour suppressor kinase phosphorylates and activates a number of protein kinases belonging to the AMP activated protein kinase ( AMPK ) subfamily . ^^^ We have used a modified tandem affinity purification strategy to identify proteins that interact with AMPKalpha , as well as the twelve AMPK related kinases that are activated by LKB 1 . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
The Peutz Jegher syndrome tumor suppressor gene encodes a protein threonine kinase , LKB 1 , which phosphorylates and activates AMPK [ adenosine monophosphate ( AMP ) activated protein kinase ] . ^^^ The deletion of LKB 1 in the liver of adult mice resulted in a nearly complete loss of AMPK activity . ^^^ Adenoviral small hairpin RNA ( shRNA ) for TORC 2 reduced PGC 1alpha expression and normalized blood glucose levels in mice with deleted liver LKB 1 , indicating that TORC 2 is a critical target of LKB1 / AMPK signals in the regulation of gluconeogenesis . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
Recent studies indicate that the LKB 1 is a key regulator of the AMP activated protein kinase ( AMPK ) , which plays a crucial role in protecting cardiac muscle from damage during ischemia . ^^^ Phosphorylation of AMPKalpha 2 at the site of LKB 1 phosphorylation ( Thr 172 ) or phosphorylation of acetyl CoA carboxylase 2 , a downstream substrate of AMPK , was ablated in ischemic heart lacking cardiac LKB 1 . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
We identified distinct gene homologues for AMPK alpha , beta and gamma subunits and for LKB 1 , MO 25 and STRAD . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
LKB 1 AMPK signaling in muscle from obese insulin resistant Zucker rats and effects of training . ^^^ We compared AMPK and ACC phosphorylation and the protein content of the upstream AMPK kinase LKB 1 and the AMPK regulated transcriptional coactivator PPARgamma coactivator 1 ( PGC 1 ) in gastrocnemius of sedentary obese Zucker rats and sedentary lean Zucker rats . ^^^ Protein expression of the AMPK kinase LKB 1 was also reduced in the muscle from obese rats by 43 % . ^^^ In summary , obese insulin resistant rodents have abnormalities in the LKB 1 AMPK PGC 1 pathway in muscle , and these abnormalities can be restored by training . . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
Following the recent identification of the tumor suppressor kinase LKB 1 as an AMPKK , a broader role for AMPK in metabolic economy has been unveiled by a new body of work from three groups that implicates the Ca ( 2+ ) / calmodulin dependent protein kinase kinases as AMPKKs . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
The ubiquitin associated domain of AMPK related protein kinases allows LKB 1 induced phosphorylation and activation . ^^^ Of the 12 human AMPK related protein kinase family members , 11 can be activated following phosphorylation of their T loop threonine residue by the LKB 1 complex . ^^^ Nine of these AMPK related kinases activated by LKB 1 contain an UBA ( ubiquitin associated ) domain immediately C terminal to the kinase catalytic domain . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
Inhibition of germline proliferation during C . elegans dauer development requires PTEN , LKB 1 and AMPK signalling . ^^^ We show here that the C . elegans orthologues of LKB 1 and AMPK cooperate during conditions of reduced insulin like signalling to establish cell cycle quiescence in the germline stem cell population , in addition to prolonging lifespan . ^^^ Our data suggest that these two signalling pathways converge on the C . elegans PTEN orthologue to coordinate germline proliferation with somatic development during dauer formation , via the regulation of AMPK and its upstream activator LKB 1 , rather than through the canonical insulin like signalling cascade . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
It has recently been shown that Akt directly phosphorylates AMPKalpha ( 1 ) / alpha ( 2 ) on Ser ( 485 / 491 ) in vitro and prevents the AMPK kinase ( AMPKK ) LKB 1 from phosphorylating AMPKalpha at its primary activation site , Thr ( 172 ) ( S Horman , D Vertommen , R Heath , D Neumann , 5 Mouton , A Woods , U Schlattner , T Wallimann , D Carling , L Hue , and MH Rider . ^^^ Expression of myrAkt 1 blunted LKB 1 induced phosphorylation of AMPKalpha at Thr ( 172 ) , which resulted in a dramatic decrease in phosphorylation of AMPK ' s target , acetyl CoA carboxylase . ^^^ Taken together , our data show that activation of Akt 1 is able to prevent activation of cardiac AMPK by LKB 1 and at least one other AMPKK , likely by prior phosphorylation of AMPKalpha ( 1 ) / alpha ( 2 ) at Ser ( 485 / 491 ) . . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
Recent work using a muscle specific knockout of the upstream kinase , LKB 1 , has confirmed that the LKB 1 > AMPK cascade is the signaling pathway responsible for many of these effects . . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
The ubiquitin associated domain of AMPK related kinases regulates conformation and LKB 1 mediated phosphorylation and activation . ^^^ Recent work indicates that the LKB 1 tumour suppressor protein kinase , which is mutated in Peutz Jeghers cancer syndrome , phosphorylates and activates a group of protein kinases that are related to AMPK ( AMP activated protein kinase ) . ^^^ Ten of the 14 AMPK related protein kinases activated by LKB 1 , including SIK ( salt induced kinase ) , MARK ( microtubule affinity regulating kinase ) and BRSK ( brain specific kinase ) isoforms , possess a ubiquitin associated ( UBA ) domain immediately C terminal to the kinase catalytic domain . ^^^ Instead , the UBA domains appear to play an essential conformational role and are required for the LKB 1 mediated phosphorylation and activation of AMPK related kinases . ^^^ This is based on the findings that mutation or removal of the UBA domains of several AMPK related kinases , including isoforms of MARK , SIK and BRSK , markedly impaired the catalytic activity and LKB 1 mediated phosphorylation of these enzymes . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
The nucleotide induced phosphorylation of AMPK was affected by changes in the concentration of intracellular Ca2+ and by Ca2+ / calmodulin dependent kinase kinase ( CaMKK ) , although most likely it was not dependent on LKB 1 kinase . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
The recent discovery that the tumour suppressor LKB 1 is an upstream kinase in the AMP activated protein kinase ( AMPK ) cascade provided a molecular link between energy metabolism and cancer . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
The activity of LKB 1 , the upstream kinase of AMPK , and the phosphorylation of eNOS at Ser 1179 were concomitant with AMPK activation responding to changes in flow rate or pulsatility . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
The AMPK signalling network contains a number of tumour suppressor genes including LKB 1 , p 53 , TSC 1 and TSC 2 , and overcomes growth factor signalling from a variety of stimuli ( via growth factors and by abnormal regulation of cellular proto oncogenes including PI3K , Akt and ERK ) . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
The LKB 1 > AMPK cascade is switched on by metabolic stresses that either inhibit ATP production ( e . g . hypoxia , hypoglycaemia ) or that accelerate ATP consumption ( e . g . muscle contraction ) . ^^^ Some hormones may activate AMPK by an LKB 1 independent mechanism involving Ca2+ / calmodulin dependent protein kinase kinases . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
The activity of the upstream kinase LKB 1 was decreased by fatty acid treatment indicating that AMPK activation was not a consequence of LKB 1 activation . ^^^ Instead , fatty acids enhanced LKB 1 phosphorylation of AMPK . ^^^ Fatty acids did not alter LKB 1 activity when either synthetic peptide or AMPK alpha ( 1 312 ) catalytic fragment was used as substrate indicating that the betagamma subunits were required for the fatty acid activation . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
Neither LKB 1 nor AMPK are the direct targets of metformin . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
When GST TPS 5 was expressed in human HEK 293 cells , Thr 49 was phosphorylated in response to 2 deoxyglucose or phenformin , stimuli that activate the AMPK via the upstream kinase LKB 1 . 2 deoxyglucose stimulated Thr 49 phosphorylation of endogenous TPS 5 in Arabidopsis cells , whereas phenformin did not . ^^^ The plant kinase was inactivated by dephosphorylation and reactivated by phosphorylation with human LKB 1 , indicating that elements of the SnRK1 / AMPK pathway are conserved in Arabidopsis and human cells . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
Treatment with staurosporine completely inhibited SIK kinase activity without any significant effect on the phosphorylation level at the LKB 1 phosphorylatable site in SIK or the activity of AMPK , another target of LKB 1 . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
The upstream kinases are also functionally conserved , and the AMPK kinases LKB 1 and Ca2+ / calmodulin dependent protein kinase kinase activate Snf 1 in mutant yeast cells lacking the native Snf 1 activating kinases , Sak 1 , Tos 3 , and Elm 1 . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
AMPK is controlled by upstream kinases which have recently been identified as LKB 1 or Ca2+ / calmodulin dependent protein kinase kinase beta ( CaMKKbeta ) . ^^^ In contrast , downregulation of LKB 1 did not affect thrombin induced AMPK activation but abolished phosphorylation of AMPK with 5 aminoimidazole 4 carboxamide ribonucleoside . ^^^ |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
NA |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
NA |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
NA |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
NA |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
NA |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
NA |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
NA |
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Interacting proteins: Q15831 and P54646 |
Pubmed |
SVM Score :0.0 |
NA |
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