| 2003 |
TSC2 is a GTPase-activating protein (GAP) directly toward Rheb; TSC2 stimulates Rheb GTP hydrolysis, reducing active Rheb-GTP levels, and thereby inhibiting mTOR-dependent phosphorylation of S6K and 4EBP1. Rheb acts downstream of TSC1/TSC2 and upstream of mTOR. |
In vitro GAP activity assays, co-immunoprecipitation, dominant-negative and constitutively active mutant expression, genetic epistasis in mammalian cells |
Genes & development |
High |
12766775 12766776 12842888 12869586
|
| 2003 |
Rheb is an essential regulator of S6 kinase (S6K) activity downstream of Tsc1/Tsc2 and upstream of TOR in Drosophila; loss-of-function Rheb mutations arrest larval growth and prevent G1-S progression, and overexpression promotes cell and tissue growth in a rapamycin-sensitive manner. |
Drosophila genetic screen, loss-of-function mutations, overexpression, rapamycin sensitivity assay |
Nature cell biology |
High |
12766775 12766776 12893813
|
| 2004 |
TSC2 GAP activity toward Rheb requires a catalytic 'asparagine thumb' (Asn residues in TSC2) rather than the arginine finger found in Ras-GAPs; Arg15 of Rheb (equivalent to Gly12 in Ras) is important for Rheb to serve as a TSC2 GAP substrate. Farnesylation and membrane localization of Rheb are not essential for Rheb to stimulate S6K phosphorylation. |
Site-directed mutagenesis, in vitro GAP activity assay, cell-based S6K phosphorylation assay |
Molecular and cellular biology |
High |
15340059
|
| 2005 |
Rheb binds directly to the mTOR catalytic domain and to LST8 within mTOR complex 1 (TOR complex 1), independently of its ability to bind TSC2. Rheb-GTP binding enables activation of the TOR kinase; mTOR polypeptides bound to Rheb(Gln64Leu) (near-90% GTP-charged) exhibit substantially higher kinase activity, while nucleotide-deficient Rheb mutants bind mTOR but trap it in an inactive state. |
Co-immunoprecipitation (in vivo and in vitro), in vitro kinase assay, switch-I domain mutagenesis, nucleotide-charging analysis |
Current biology : CB |
High |
15854902
|
| 2005 |
Amino acid withdrawal reversibly inhibits binding of Rheb to endogenous and recombinant mTOR without altering Rheb GTP-charging. The inhibitory effect is exerted through an action on mTOR at a site largely distinct from the Rheb-binding region; deletion of the C-terminal lobe of the mTOR catalytic domain abolishes the inhibitory effect of amino acid withdrawal on Rheb binding. |
Co-immunoprecipitation, mTOR deletion mutants, GTP-charging assays, amino acid withdrawal/re-addition experiments |
The Journal of biological chemistry |
High |
15878852
|
| 1994 |
Rheb is a novel Ras-family small GTPase that binds and hydrolyzes GTP and contains a C-terminal CAAX box predicted to signal farnesylation for membrane targeting. It is rapidly and transiently induced in hippocampal neurons by seizures and NMDA-dependent synaptic activity. |
Differential cloning, bacterial fusion protein GTP-binding and GTPase activity assay, Northern blot, sequence analysis |
The Journal of biological chemistry |
Medium |
8206940
|
| 1997 |
Rheb is farnesylated in vitro and in vivo and is sensitive to farnesyltransferase inhibition. Unlike Ras, Rheb does not transform NIH 3T3 cells but instead antagonizes oncogenic Ras transformation and signaling, similar to KRev-1/Rap1A. |
In vitro and in vivo farnesylation assays, NIH 3T3 transformation assay, oncogenic Ras co-expression |
The Journal of biological chemistry |
Medium |
9099708
|
| 1997 |
Rheb interacts with Raf-1 kinase; unlike H-Ras, the Rheb-Raf-1 interaction is potentiated by growth factors combined with cAMP-elevating agents. Protein kinase A-dependent phosphorylation of Ser43 in Raf-1 reciprocally potentiates Raf-1 binding to Rheb and decreases its interaction with H-Ras. A single amino acid in the G2 effector domain is critical for the differential binding properties of Rheb versus Ras. |
Co-immunoprecipitation, mutagenesis, cAMP stimulation, PKA phosphorylation assays |
Molecular and cellular biology |
Medium |
9001246
|
| 2002 |
Rheb is maintained in a high GTP-bound (activated) state in mammalian cells, much more so than Ras or Rap1, and its activation state is unaffected by changes in growth conditions. Rheb binds B-Raf kinase and inhibits B-Raf kinase activity and B-Raf-dependent Elk-1 transcriptional activation. |
GTP/GDP loading assays in three mammalian cell lines, co-immunoprecipitation of endogenous Rheb with B-Raf, in vitro kinase assay, Elk-1 reporter assay |
Oncogene |
Medium |
12214276
|
| 2003 |
TSC2 binds Rheb-GTP in vitro and reduces Rheb GTP levels in vivo; overexpression of Rheb but not Rap1 promotes S6 kinase activation in a rapamycin-dependent manner. Rheb-mediated S6 phosphorylation is blocked by a farnesyl transferase inhibitor. |
In vitro pulldown (Rheb-GTP binding), in vivo GTP-loading assay, S6K phosphorylation assay, FTI treatment |
The Journal of biological chemistry |
High |
12842888
|
| 2004 |
Constitutive activation of the Rheb/mTOR/S6K cassette (by TSC1/TSC2 deletion or ectopic Rheb expression) is sufficient to induce insulin resistance by downregulating IRS1 and IRS2, rendering Akt refractory to activation by IRS-dependent growth factor pathways. |
Genetic deletion of TSC1/TSC2 in mouse embryonic fibroblasts, ectopic Rheb overexpression, Western blot for IRS1/IRS2 protein levels and Akt phosphorylation |
Current biology : CB |
High |
15380067
|
| 2004 |
Rheb inhibits wild-type B-Raf kinase activity and this function is independent of mTOR/rapamycin (mTOR-independent). The interaction of endogenous Rheb with B-Raf is enhanced by serum and Ras overexpression. A farnesylation-defective Rheb mutant can still co-immunoprecipitate with and inhibit B-Raf, indicating that farnesylation is not required for B-Raf inhibition by Rheb. B-Raf inhibition and S6K activation are separable activities of Rheb. |
Co-immunoprecipitation, in vitro B-Raf kinase assay, rapamycin treatment, farnesylation-defective Rheb mutant |
The Journal of biological chemistry |
Medium |
15150271
|
| 2005 |
Rheb localizes to endomembranes (endoplasmic reticulum, Golgi) rather than the plasma membrane, dependent on C-terminal CAAX farnesylation but not palmitoylation. Rce1 and Icmt post-prenylation processing steps are required for proper Rheb endomembrane localization; without the polybasic region or palmitoylation sites, Rheb diffusely localizes when Rce1 or Icmt are absent. |
Confocal microscopy with fluorescent protein fusions, Rce1 and Icmt knockout fibroblasts, farnesyltransferase and geranylgeranyltransferase inhibitors, CAAX cysteine mutagenesis |
The Journal of biological chemistry |
High |
16046393
|
| 2005 |
Rheb farnesylation (via the C-terminal CAAX motif) is completely blocked by the FTI SCH66336 (lonafarnib) and Rheb is not alternatively geranylgeranylated. Rheb and Rheb2 C-terminal peptides are substrates for farnesyltransferase but not geranylgeranyltransferase-1 in vitro. FTI-mediated inhibition of mTOR/S6 signaling is reversed by a Rheb mutant engineered for geranylgeranylation, establishing Rheb as the critical FTI target for mTOR pathway inhibition. |
In vitro prenylation assay with purified enzymes, metabolic labeling in cell culture, S6 phosphorylation assay, Rheb CSVL geranylgeranylatable mutant rescue |
The Journal of biological chemistry |
High |
16006564
|
| 2006 |
Rheb inhibits both B-Raf and C-Raf kinase activities and inhibits B-Raf/C-Raf heterodimerization; these effects are rapamycin-insensitive (mTOR-independent). Rheb activation is associated with decreased B-Raf (Ser-446) and C-Raf (Ser-338) phosphorylation and inhibits the association of B-Raf with H-Ras. |
In vitro kinase assay, co-immunoprecipitation of B-Raf/C-Raf heterodimers, rapamycin treatment |
The Journal of biological chemistry |
Medium |
16803888
|
| 2006 |
Drosophila Rheb (dRheb) has an inhibitory effect on dTORC2 activity in Drosophila S2 cells; this appears to be mediated by a feedback mechanism involving dTORC1 and dS6K rather than direct Rheb-TORC2 interaction. Mammalian Rheb does not activate TORC2 in HEK293 cells. TSC1/TSC2 have opposite effects on TORC1 and TORC2. |
S2 cell RNAi, Akt and S6K phosphorylation as TORC2/TORC1 functional readouts, Drosophila genetics |
Proceedings of the National Academy of Sciences of the United States of America |
Medium |
16627617
|
| 2007 |
Rheb activates mTOR by antagonizing FKBP38, an endogenous inhibitor of mTOR structurally related to FKBP12; Rheb interacts directly with FKBP38 in a GTP-dependent manner and prevents FKBP38 association with mTOR. |
Co-immunoprecipitation, in vitro binding assay, RNAi knockdown, mTOR kinase assay |
Science (New York, N.Y.) |
Medium |
17991864
|
| 2009 |
The Rheb-FKBP38 interaction proposed in Science 2007 was not detected in three independent in vitro assay systems; cell biological experiments show FKBP38 plays only a very minor role, if any, in mTORC1 activation. FKBP38 is therefore not the long-sought Rheb effector linking Rheb to mTORC1 activation. |
Three independent in vitro binding assays, cell biological experiments |
FEBS letters |
Medium |
19222999
|
| 2009 |
Rheb specifically activates mTORC1 but not mTORC2 in a GTP-dependent manner in vitro; the activation requires the effector domain of Rheb and a raptor-containing mTORC1 complex. Rheb increases binding of the substrate 4E-BP1 to mTORC1. Other GTPases (KRas, RalA/B, Cdc42) do not activate mTORC1. Rheb does not induce mTOR autophosphorylation. FKBP38-depleted mTORC1 preparations are still activated by Rheb. |
In vitro mTORC1 kinase assay using immunoprecipitated mTORC1 from nutrient-starved cells, recombinant Rheb addition, effector domain mutants, substrate binding assay |
The Journal of biological chemistry |
High |
19299511
|
| 2008 |
Rheb directly binds and activates PLD1 (but not PLD2) in a GTP-dependent manner in vitro, establishing PLD1 as a bona fide effector of Rheb. PLD1 is required (by RNAi) for Rheb activation of the mTOR pathway; TSC2 overexpression suppresses PLD1 activation, and TSC2 deletion elevates basal PLD activity. |
In vitro binding and PLD activity assay with recombinant proteins, RNAi knockdown, PLD activity assay, PI3K/AMPK pharmacological inhibitors |
Proceedings of the National Academy of Sciences of the United States of America |
High |
18550814
|
| 2009 |
Rheb inhibits aggresome formation and sensitizes cells to death upon misfolded protein accumulation by disrupting the interaction between dynein and misfolded protein cargos, thereby blocking dynein-dependent retrograde transport. This function is independent of mTOR complex 1. |
Genetic TSC1/TSC2 knockout cells, Rheb overexpression/knockdown, co-immunoprecipitation of dynein with misfolded protein cargos, rapamycin treatment to distinguish mTOR-dependent from mTOR-independent effects |
Proceedings of the National Academy of Sciences of the United States of America |
Medium |
19458266
|
| 2009 |
Rheb localizes primarily to endoplasmic reticulum and Golgi apparatus (Rheb1 and Rheb2). Post-prenylation processing by Rce1 and Icmt is required for proper Rheb localization but dispensable for Rheb-induced activation of S6K; farnesylthiosalicylic acid (FTS) blocks S6K activation induced by constitutively active mTOR downstream of Rheb, suggesting FTS inhibits mTOR downstream of Rheb. |
Immunofluorescence microscopy, Rce1 and Icmt knockout cells, S6K phosphorylation assay, FTS treatment |
Oncogene |
Medium |
19838215
|
| 2011 |
PRAK (p38-regulated/activated kinase) directly phosphorylates Rheb at Ser130, which impairs the nucleotide-binding ability of Rheb and inhibits Rheb-mediated mTORC1 activation. This operates downstream of a p38β-PRAK cascade activated by energy starvation, independently of AMPK-mediated TSC2 and Raptor phosphorylation. |
In vitro kinase assay (PRAK phosphorylating Rheb), site-directed mutagenesis of Ser130, nucleotide binding assay, mTORC1 activity assay, PRAK/p38β depletion experiments |
Nature cell biology |
High |
21336308
|
| 2008 |
Rheb overexpression induces multiple axon formation in hippocampal neurons via mTOR; Rheb suppression by RNAi blocks axon specification. mTOR acts through 4E-BP1 translation control; downstream of Rheb-mTOR, Rap1B levels are maintained by counteracting Smurf2-mediated degradation. |
Neuronal overexpression/RNAi in dissociated hippocampal neurons, morphological readout (axon number), rapamycin inhibition, 4E-BP1 mutant expression, Smurf2 RNAi rescue |
The Journal of biological chemistry |
Medium |
18842593
|
| 2008 |
ATF6α transcription factor induces Rheb expression, which activates mTOR signaling independently of Akt, promoting survival of quiescent/dormant tumor cells. Knockdown of ATF6α or Rheb reverts dormant tumor cell resistance to rapamycin. |
shRNA knockdown of ATF6α and Rheb, rapamycin treatment, in vivo dormancy model, mTOR activity assays |
Proceedings of the National Academy of Sciences of the United States of America |
Medium |
18650380
|
| 2010 |
Tsc2–Rheb signaling controls EphA receptor-dependent axon guidance; EphA receptor activation by ephrin-A ligands decreases ERK1/2-mediated inhibition of Tsc2, thereby inactivating the mTOR pathway. Tsc2 deficiency with hyperactive Rheb constitutively activates mTOR and inhibits ephrin-induced growth cone collapse. |
Tsc2 haploinsufficient mice (retinogeniculate projection analysis), ERK1/2 activity assay in neurons, growth cone collapse assay, mTOR activity assays |
Nature neuroscience |
High |
20062052
|
| 2017 |
Cryo-EM structure of RHEB-mTORC1 at 3.4 Å shows RHEB binds to mTOR distally from the kinase active site and causes a global conformational change that allosterically realigns active-site residues to accelerate catalysis. Cancer-associated hyperactivating mutations map to elements that maintain the inactive state and biochemically mimic RHEB relieving auto-inhibition. |
Cryo-EM structure determination (3.0 Å mTORC1; 3.4 Å RHEB-mTORC1), crystal structures of RAPTOR-TOS and mTOR FRB-substrate complexes, in vitro kinase assays, biochemical characterization of cancer mutations |
Nature |
High |
29236692
|
| 2018 |
Ubiquitination of Rheb by the lysosome-anchored E3 ligase RNF152 promotes Rheb binding to the TSC complex and keeps Rheb inactive. EGF activates AKT-dependent phosphorylation of USP4, causing deubiquitination of Rheb and its release from the TSC complex, enabling mTORC1 activation. |
Co-immunoprecipitation, ubiquitination assays, RNF152 and USP4 knockdown/overexpression, AKT inhibition, mTORC1 activity assays |
Cell research |
Medium |
30514904
|
| 2015 |
MCRS1 is required for amino acid-dependent mTORC1 activation by maintaining Rheb at lysosome surfaces; MCRS1 suppression promotes Rheb/TSC2 interaction, renders Rheb inactive, and relocalizes Rheb from lysosomes to recycling endocytic vesicles. |
siRNA knockdown, inducible Cre/lox MEFs, co-immunoprecipitation (Rheb-TSC2, Rheb-MCRS1), immunofluorescence localization of Rheb |
Developmental cell |
Medium |
25816988
|
| 2015 |
Rheb inhibits protein synthesis by enhancing phosphorylation of eIF2α through activation of the ER kinase PERK, in a manner independent of mTORC1. |
Rheb overexpression and knockdown, eIF2α phosphorylation assays, PERK inhibition/knockdown, protein synthesis assays |
Cell reports |
Medium |
25660019
|
| 2013 |
GTP-bound Rheb interacts with BACE1 (β-secretase) and promotes its degradation through proteasomal and lysosomal pathways, independently of mTOR signaling. Rheb overexpression depletes BACE1 protein and reduces Aβ generation, while Rheb knockdown promotes BACE1 accumulation. |
Co-immunoprecipitation (GTP-Rheb with BACE1), proteasome and lysosome inhibitor experiments, Rheb overexpression/RNAi, Aβ measurement |
The Journal of biological chemistry |
Medium |
24368770
|
| 2016 |
Arginine suppresses lysosomal localization of the TSC complex and its interaction with Rheb, thereby relieving allosteric inhibition of Rheb by TSC and enabling maximal mTORC1 activation by growth factors. This mechanism does not involve regulation of mTORC1 lysosomal localization. |
Lysosomal fractionation, co-immunoprecipitation of TSC2 with Rheb under arginine-replete vs. -depleted conditions, mTORC1 activity assays in multiple cell types including hESC-derived lineages |
eLife |
High |
26742086
|
| 2021 |
Structural analysis at near-atomic resolution reveals the TSC complex has an arch-shaped 2:2:1 (TSC1:TSC2:TBC1D7) stoichiometry. Structural and biochemical analysis of the TSC2 GAP domain–Rheb interface confirms that the TSC2 asparagine thumb (N1643) stabilizes the γ-phosphate of GTP to accelerate Rheb GTP hydrolysis. |
Cryo-EM structure of human TSC complex, biochemical GAP activity assays, mutagenesis of catalytic residues |
Nature communications |
High |
33436626
|
| 2021 |
Rheb is dynamically trafficked to the mitochondrial matrix through its interaction with Tom20 in response to neuronal activity and lactate. Mitochondria-localized Rheb activates pyruvate dehydrogenase (PDH) by physically associating with PDH phosphatase (PDP), enhancing PDP activity and its association with the catalytic E1α-subunit of PDH to reduce PDH phosphorylation and increase acetyl-CoA and ATP production. This function is independent of mTORC1. |
SC-specific Rheb knockout mice and gain-of-function models, mitochondrial fractionation, co-immunoprecipitation (Rheb-Tom20, Rheb-PDP), PDH activity assay, acetyl-CoA and ATP measurement, rapamycin comparison |
Developmental cell |
High |
33725483
|
| 2021 |
SC-specific Rheb knockout suppresses pyruvate dehydrogenase (PDH) activity independently of mTORC1 and shifts pyruvate metabolism toward lactate production in Schwann cells, causing age-dependent peripheral axon degeneration. |
Schwann cell-specific Rheb knockout mice, PDH activity assay, lactate measurement, peripheral nerve function tests |
Developmental cell |
High |
34619097
|
| 2019 |
ATF6 transcription factor directly transcriptionally induces RHEB expression (confirmed by chromatin immunoprecipitation) in cardiac myocytes, which activates mTORC1 to promote compensatory cardiac hypertrophy. ATF6 cardiac-specific knockout blunts hypertrophy and is rescued by ectopic RHEB. |
Chromatin immunoprecipitation (ATF6 on RHEB promoter), cardiac-specific ATF6 knockout mice (TAC and exercise models), AAV9-RHEB rescue, mTORC1 activity assays |
Circulation research |
High |
30582446
|
| 2018 |
A small molecule (NR1) binds Rheb in the switch II domain and selectively blocks mTORC1 signaling (inhibits S6K1 phosphorylation) without inhibiting AKT or ERK. Unlike rapamycin, NR1 does not cause prolonged mTORC2 inhibition. Rheb switch II domain point mutations that impair mTORC1 activation are mimicked by NR1 binding. |
Small molecule binding assay (NR1 binding to Rheb switch II), S6K1/AKT/ERK phosphorylation assays in cells, in vivo mouse kidney and muscle mTORC1 assay, comparison with rapamycin |
Nature communications |
Medium |
29416044
|
| 2017 |
Rheb inhibits beiging of white adipose tissue through an mTORC1-independent mechanism involving stabilization of PDE4D5, which degrades cAMP and reduces PKA activity and UCP1 expression. Adipose-specific Rheb knockout increases cAMP, PKA activity, and UCP1; partial, but not complete, rescue by rapamycin confirms the mTORC1-independent component. |
Adipose-specific Rheb knockout mice, cAMP measurement, PKA activity assay, PDE4D5 protein stability assay, rapamycin treatment comparison, primary adipocyte overexpression |
Diabetes |
Medium |
28242620
|
| 2011 |
Rheb knockout mice die around midgestation, most likely due to impaired cardiovascular development; Rheb-null embryonic fibroblasts show decreased TORC1 activity, reduced cell size, and impaired proliferation. Rheb heterozygosity extends the lifespan of Tsc1-null embryos, establishing genetic interaction between Tsc1 and Rheb in vivo. |
Rheb knockout mouse generation, embryonic phenotype analysis, embryonic fibroblast TORC1 activity and cell size assays, Tsc1/Rheb double-mutant epistasis |
Molecular and cellular biology |
High |
21321084
|
| 2019 |
In Treg cells, Rheb1 and Rheb2 (Rheb GTPases) are central regulators of amino acid-dependent mTORC1 activation; mice with Rheb1/Rheb2-deficient Treg cells develop fatal autoimmune disease with reduced effector Treg accumulation. Rheb1/Rheb2 enforce the eTreg cell suppressive gene signature, whereas Rag GTPases regulate mitochondrial and lysosomal fitness. |
Conditional Treg-specific Rheb1/Rheb2 double-knockout mice, mTORC1 activity assays, immune phenotyping, gene expression profiling |
Immunity |
High |
31668641
|
| 2010 |
NMR structure of Rheb-GDP shows the canonical Ras GTPase fold with GDP-dependent dynamics in the switch I and II regions. NMR revealed Ras effector-like binding of activated Rheb to the c-Raf Ras-binding domain (RBD) but with ~1000-fold lower affinity than Ras/RBD, suggesting lack of functional interaction with c-Raf. |
NMR structure determination of Rheb-GDP, NMR binding assay (Rheb to c-Raf RBD), affinity measurement |
The Journal of biological chemistry |
Medium |
20685651
|
| 2011 |
Rheb and raptor negatively regulate skeletal myogenic differentiation through suppression of IRS1; knockdown of Rheb enhances myogenic differentiation with increased Akt activation and elevated IRS1 protein levels and reduced IRS1 Ser307 phosphorylation. IRS1 knockdown eliminates the enhancement elicited by Rheb knockdown, placing IRS1 downstream of the Rheb-mTOR/raptor inhibitory pathway in myogenesis. |
C2C12 myoblast siRNA knockdown and overexpression, myogenic differentiation assays, IRS1/Akt phosphorylation Western blots, epistasis by IRS1 co-knockdown |
The Journal of biological chemistry |
Medium |
21852229
|
| 2019 |
Brain somatic doublet mutation RHEB p.Y35L increases Rheb GTPλS-binding activity, elevates mTOR/S6 phosphorylation in cells, and when expressed via in utero electroporation in mice causes cytomegalic neurons, dysregulated neuron migration, abnormal EEG, and seizures recapitulating focal cortical dysplasia type II; rapamycin rescues the EEG and seizure phenotype. |
Whole exome sequencing, GTPλS binding assay, in utero electroporation in mice, S6 phosphorylation assay, EEG recording, rapamycin treatment |
Experimental & molecular medicine |
High |
31337748
|