| 1994 |
PHAS-I (4E-BP1) binds to eIF4E and inhibits protein synthesis when unphosphorylated; MAP kinase phosphorylates Ser-64, which prevents PHAS-I from binding eIF4E, linking MAP kinase signaling to translational control. |
In vitro binding assay with immobilized PHAS-I, mRNA cap affinity resin, and kinase assays in adipocyte extracts |
Science |
High |
7939721
|
| 1994 |
PHAS-I (4E-BP1) is a 117-amino-acid heat-stable protein that is phosphorylated in response to insulin and growth factors; it is expressed at highest levels in fat and skeletal muscle. |
cDNA cloning, in vitro translation, SDS-PAGE, Western blot, Northern blot |
Proceedings of the National Academy of Sciences of the United States of America |
Medium |
8170978
|
| 1995 |
Phosphorylation of PHAS-I by growth factors (PDGF, IGF-I) promotes dissociation of the PHAS-I·eIF-4E complex; both effects are abolished by rapamycin, placing PHAS-I downstream of the rapamycin-sensitive (mTOR/p70S6K) pathway in smooth muscle cells. |
Co-immunoprecipitation, phosphorylation assay, rapamycin treatment, p70S6K activity assay in rat aortic smooth muscle cells |
Proceedings of the National Academy of Sciences of the United States of America |
Medium |
7638171
|
| 1996 |
Rapamycin blocks 4E-BP1 phosphorylation and specifically inhibits cap-dependent (but not cap-independent) translation; dephosphorylation/activation of 4E-BP1 is the mechanistic basis for rapamycin's suppression of cap-dependent translation. |
In vitro translation assays comparing cap-dependent vs. IRES-driven reporters; Western blot of 4E-BP1 phosphorylation in rapamycin-treated NIH 3T3 cells; FK506 competition |
The EMBO journal |
High |
8599949
|
| 1996 |
4E-BP1 phosphorylation is mediated by the FRAP/mTOR–p70S6K pathway and is independent of MAP kinase (ERK/p42mapk), established by insulin stimulation studies in cells lacking MAP kinase activation and use of MEK inhibitors. |
Pharmacological inhibitors (rapamycin, wortmannin, SQ20006), receptor point mutants (PDGFR 740F/751F), kinase activity assays in multiple cell types |
Proceedings of the National Academy of Sciences of the United States of America |
High |
8633019
|
| 1996 |
Both insulin and diabetes regulate PHAS-I·eIF-4E complex formation in rat skeletal muscle through changes in PHAS-I phosphorylation (not eIF-4E phosphorylation), directly demonstrating this axis controls muscle protein synthesis in vivo. |
Western blot and co-immunoprecipitation of eIF-4E/PHAS-I complexes in rat skeletal muscle; insulin and alloxan-diabetes models |
The American journal of physiology |
Medium |
8779938
|
| 1997 |
mTOR (FRAP) directly phosphorylates PHAS-I (4E-BP1) on serine and threonine residues in vitro; this phosphorylation inhibits 4E-BP1 binding to eIF-4E and the rapamycin-sensitive kinase activity of mTOR is required for PHAS-I phosphorylation in cells. |
In vitro kinase assay with mTOR immunoprecipitate; phospho-amino acid analysis; in vivo rapamycin treatment of insulin-stimulated HEK293 cells |
Science |
High |
9204908
|
| 1997 |
mTOR mutants resistant to rapamycin·FKBP12 protect eIF4E-BP1 from rapamycin-induced dephosphorylation, and this protection requires an active mTOR catalytic domain, demonstrating that mTOR directly regulates 4E-BP1 phosphorylation (parallel to, not downstream of, S6K1). |
Transient transfection of rapamycin-resistant mTOR and kinase-dead mTOR mutants; Western blot of 4E-BP1 phosphorylation |
The Journal of biological chemistry |
High |
9334222
|
| 1998 |
RAFT1/mTOR directly phosphorylates 4E-BP1 on Thr-36 and Thr-45 in vitro; serum stimulates RAFT1 kinase activity with kinetics parallel to 4E-BP1 phosphorylation; phosphorylation of Thr-45 is identified as the major regulator of the 4E-BP1–eIF-4E interaction in vivo. |
In vitro kinase assay with immunoprecipitated RAFT1; phosphopeptide mapping; in vivo phosphorylation analysis |
Proceedings of the National Academy of Sciences of the United States of America |
High |
9465032
|
| 1998 |
The PI3K/Akt pathway is required for 4E-BP1 phosphorylation: a dominant-negative Akt blocks insulin-induced 4E-BP1 phosphorylation; activated Akt induces 4E-BP1 phosphorylation on the same sites as serum, but this requires FRAP/mTOR activity downstream. |
Dominant-negative and constitutively-active Akt mutant expression; wortmannin/rapamycin inhibitors; phosphorylation-site analysis by Western blot and co-IP with eIF4E |
Genes & development |
High |
9472019
|
| 1999 |
4E-BP1 phosphorylation by FRAP/mTOR follows a hierarchical two-step mechanism: mTOR first phosphorylates Thr-37 and Thr-46 (priming events) even when 4E-BP1 is bound to eIF4E, and these are required for subsequent phosphorylation of carboxy-terminal serum-sensitive sites (Ser-65, Thr-70) that cause eIF4E release. |
In vitro FRAP/mTOR kinase assays; phosphopeptide mapping; mass spectrometry identification of phosphorylation sites; mutational analysis of Thr-37/Thr-46 |
Genes & development |
High |
10364159
|
| 1999 |
An mTOR-associated kinase (distinct from mTOR itself) phosphorylates 4E-BP1 within a peptide containing Ser-64 and Thr-69, and this phosphorylation (predominantly at Ser-64) is sufficient to dissociate 4E-BP1 from eIF-4E. |
mTOR immunoprecipitate fractionation; in vitro kinase assay; co-immunoprecipitation with eIF4E |
FEBS letters |
Medium |
10471835
|
| 1999 |
Akt (PKB), but not atypical PKCλ, is required for insulin-induced 4E-BP1 phosphorylation, demonstrated using an Akt mutant (Akt-AA) that blocks insulin activation. |
Dominant-negative Akt and kinase-defective PKCλ expression in L6 myotubes and CHO cells; Western blot for 4E-BP1 phosphorylation |
The Journal of biological chemistry |
Medium |
10400692
|
| 2002 |
UVB irradiation induces 4E-BP1 phosphorylation at Thr-36, Thr-45, Ser-64, and Thr-69 through the p38/MSK1 pathway (not PI3K/Akt), causing dissociation of 4E-BP1 from eIF-4E; dominant-negative p38 or MSK1 block this phosphorylation. |
p38 and MSK1 inhibitors; dominant-negative kinase mutant expression; in vivo phosphorylation analysis; co-immunoprecipitation with eIF4E |
The Journal of biological chemistry |
Medium |
11777913
|
| 2003 |
Both the N-terminal RAIP motif and the C-terminal TOS motif of PHAS-I/4E-BP1 are required for efficient phosphorylation by mTOR in vitro and in vivo; wild-type but not RAIP- or TOS-mutant PHAS-I co-immunoprecipitates with raptor, and raptor overexpression enhances mTOR phosphorylation of wild-type but not mutant PHAS-I. |
In vitro mTOR kinase assay with RAIP/TOS mutant recombinant proteins; co-immunoprecipitation with HA-tagged raptor; in vivo phosphorylation assay |
The Journal of biological chemistry |
High |
12665511
|
| 2003 |
A functional TOS motif in 4E-BP1 is required for binding to raptor (mTOR-associated protein), for efficient in vitro phosphorylation by the mTOR/raptor complex, for multisite in vivo phosphorylation, and for eIF4E release; a TOS-motif mutation (F114A) reduces cell size. |
In vitro mTOR/raptor complex kinase assay; co-immunoprecipitation of raptor and 4E-BP1; in vivo phosphorylation; cell size measurement |
Current biology |
High |
12747827
|
| 2003 |
Ser-64 and Ser-111 phosphorylation of PHAS-I are dispensable for insulin-stimulated dissociation from eIF4E; phosphorylation of the Thr sites (Thr-36/45, Thr-69) is the primary determinant of eIF4E release. |
Alanine substitution mutants (A64, A111) of PHAS-I; in vivo phosphorylation analysis; eIF4E binding assay |
The Journal of biological chemistry |
Medium |
14507920
|
| 2007 |
FOXO1 transcription factor binds the 4E-BP1 gene promoter and induces its expression in skeletal muscle; increased 4E-BP1 abundance reduces Raptor–mTOR association, decreases p70S6K phosphorylation, and attenuates protein synthesis, linking FOXO1 to translational repression via 4E-BP1 upregulation. |
Inducible FOXO1-ER fusion protein system; promoter-binding assay (ChIP); Western blot for 4E-BP1, Raptor, mTOR; [14C]phenylalanine incorporation; transgenic mouse model |
The Journal of biological chemistry |
Medium |
17510058
|
| 2007 |
4E-BP1 is a substrate for polyubiquitination; hyperphosphorylated forms of 4E-BP1 are simultaneously polyubiquitinated, bind eIF4E poorly, and are subject to proteasomal degradation. Phosphatase inhibition (calyculin A) reduces 4E-BP1 half-life by promoting ubiquitination of phosphorylated forms. |
Proteasome inhibitor (MG132), phosphatase inhibitor (calyculin A), m7GTP-Sepharose affinity chromatography, cycloheximide chase |
Oncogene |
Medium |
17653084
|
| 2008 |
4E-BP1 gene is a direct transcriptional target of ATF4; ATF4-mediated induction of 4E-BP1 is required for beta cell survival under ER stress, as 4E-BP1 deletion increases susceptibility to ER stress-mediated apoptosis and exacerbates hyperglycemia in diabetic mouse models. |
Reporter gene assay for Eif4ebp1 promoter; Eif4ebp1 knockout mice; siRNA knockdown in MIN6 cells; ER stress induction with tunicamycin/thapsigargin |
Cell metabolism |
High |
18316032
|
| 2008 |
Rapamycin differentially inhibits S6K versus 4E-BP1: S6K activity is inhibited throughout rapamycin treatment, but 4E-BP1 phosphorylation recovers within 6 h despite continued rapamycin exposure; this recovered phosphorylation is rapamycin-resistant but still requires mTOR and Raptor (mTORC1 activity). |
Rapamycin time-course experiments; siRNA knockdown of Raptor and Rictor; mTOR kinase-dead mutants; phospho-Western blot in multiple cell types |
Proceedings of the National Academy of Sciences of the United States of America |
High |
18955708
|
| 2009 |
Smad4 directly binds a conserved element in the 4E-BP1 gene promoter and enhances its transcription; TGFβ-mediated antiproliferative signaling requires 4E-BP1, as knockdown or knockout of 4E-BP1 abolishes TGFβ growth inhibition. |
Promoter-binding/reporter assays; co-Smad manipulation; 4E-BP1 siRNA/shRNA knockdown in human cancer cells; 4E-BP1-/- mouse embryonic fibroblasts |
The EMBO journal |
High |
19834456
|
| 2009 |
RhoE inhibits 4E-BP1 phosphorylation in response to extracellular stimuli without affecting mTOR activity (as evidenced by normal S6K phosphorylation and mTOR/Raptor dynamics), prevents eIF4E release from 4E-BP1, and thereby inhibits cap-dependent translation including cyclin D1 and c-Myc expression. |
RhoE overexpression; co-immunoprecipitation of 4E-BP1/eIF4E; phospho-Western blot for mTOR substrates; cap-dependent translation reporter assays |
The Journal of biological chemistry |
Medium |
19850923
|
| 2010 |
4E-BP1 and ERK signaling pathways converge on cap-dependent translation; AKT independence in tumors with comutated PIK3CA/PTEN and ERK pathways is mediated by redundant 4E-BP1 regulation; 4E-BP1 knockdown reduces tumor dependence on AKT/ERK signaling, while dominant-active 4E-BP1 restores sensitivity. |
siRNA knockdown of 4E-BP1; dominant-active 4E-BP1 mutant expression; AKT and MEK inhibitor treatment; colony formation and proliferation assays in cancer cell lines with defined mutations |
Cancer cell |
Medium |
20609351
|
| 2010 |
In mouse cardiomyocytes, ablation of mTOR leads to accumulation of unphosphorylated (active) 4E-BP1, resulting in dilated cardiomyopathy; genetic co-ablation of 4E-BP1 together with mTOR markedly rescues apoptosis, cardiac function, and survival, demonstrating that excessive 4E-BP1 activity mediates the cardiac phenotype of mTOR loss. |
Cardiac-specific mTOR conditional knockout mice; double mTOR/4E-BP1 knockout mice; echocardiography; histology; apoptosis assays |
The Journal of clinical investigation |
High |
20644257
|
| 2012 |
Phosphorylated 4E-BP1 (Thr37/46) co-localizes with PLK1 at centrosomes during mitosis; 4E-BP1 directly interacts with PLK1 in vitro and in vivo via its C-terminal aa 77-118; PLK1 phosphorylates 4E-BP1 in vitro; 4E-BP1 depletion causes polyploidy, chromosomal misalignment, and multipolar spindles. |
Co-immunoprecipitation; in vitro kinase assay with PLK1; siRNA knockdown; immunofluorescence co-localization; flow cytometry |
Cell cycle |
Medium |
22918237
|
| 2013 |
mTOR/4E-BP1 signaling rhythmically controls VIP mRNA translation in the suprachiasmatic nucleus (SCN); 4E-BP1 KO increases VIP expression and amplitude of molecular rhythms, accelerates re-entrainment to shifted light/dark cycles, and increases resistance to constant-light disruption, while Mtor+/- mice show opposite effects. |
4E-BP1 knockout mice; Mtor heterozygous mice; VIP protein and mRNA measurement; behavioral circadian assays; polysome fractionation |
Neuron |
High |
23972597
|
| 2013 |
Phosphorylated EIF4EBP1 (4E-BP1) localizes to the meiotic spindle in mouse oocytes; different phosphorylation-site variants (pThr37/46, pSer65, pThr70) appear at distinct spindle positions at different meiotic stages, suggesting spatially regulated translational control. 4E-BP1 is the only 4E-BP isoform present as protein in oocytes. |
cDNA microarray enrichment assay on isolated MII spindles; immunofluorescence with phospho-site-specific antibodies; Western blot |
Genetics |
Medium |
23852387
|
| 2016 |
CDK1 phosphorylates 4E-BP1 at Ser-83 during mitosis, generating a mitosis-specific hyperphosphorylated δ-isoform; pSer83 accumulates at centrosomes during prophase/metaphase; Ser83 phosphorylation does not affect general cap-dependent translation but the S83A mutant partially reverses Merkel cell polyomavirus small T antigen-induced cell transformation. |
Mass spectrometry identification of CDK1 phosphorylation sites; phospho-Ser83-specific antibody; co-localization imaging; S83A mutant expression; transformation assay |
Proceedings of the National Academy of Sciences of the United States of America |
Medium |
27402756
|
| 2016 |
Non-phosphorylated 4E-BP1 interacts with p21 (CDKN1A) and promotes its degradation; mTORC1-mediated phosphorylation of 4E-BP1 prevents this interaction, stabilizing p21 protein levels, thereby linking mTORC1 activity to p21-dependent cell cycle control. |
Co-immunoprecipitation; Western blot for p21 levels under mTORC1 inhibition; cell line and patient tissue correlation analysis |
Nature communications |
Medium |
26832959
|
| 2017 |
Snail transcription factor directly binds three E-boxes in the human 4E-BP1 promoter and represses 4E-BP1 transcription; Snail overexpression reduces 4E-BP1 expression, promotes cap-dependent translation, and confers resistance to mTOR kinase inhibitors; genetic or pharmacological Snail inhibition restores 4E-BP1 and resensitizes cancer cells. |
ChIP assay; promoter reporter assay; ectopic Snail expression and knockdown; Western blot; polysome profiling; tumor xenograft models |
Nature communications |
High |
29263324
|
| 2019 |
CDK12 phosphorylates 4E-BP1 at Ser-65 and Thr-70 (Ser-Pro sites) subsequent to mTORC1 priming phosphorylations at T37/T46, controlling 4E-BP1 exchange with eIF4G at 5'-caps of CHK1 and other mTORC1-target mRNAs; RIP-seq and Ribo-seq demonstrate CDK12 regulates a specific translation network including mitotic/centromere genes. |
In vitro CDK12 kinase assay; RIP-seq; ribosome profiling (Ribo-seq); CDK12 knockdown/knockout; confocal imaging of mitotic defects |
Genes & development |
High |
30819820
|
| 2019 |
4E-BP1 loss in pancreatic cancer cells results in selective upregulation of translational efficiency of mRNAs encoding DNA replication/repair proteins (RRM2, CDC6), rendering DNA replication insensitive to mTOR inhibitors; this is rescued by eIF4A inhibitors (silvestrol derivatives). |
Genome-wide polysome profiling; 4E-BP1 depletion; Western blot for CDC6/RRM2; patient sample correlation; 4E-BP1/2 DKO mouse pancreatitis model |
JCI insight |
Medium |
31672935
|
| 2019 |
The mitotic δ-isoform of 4E-BP1 (hyperphosphorylated at Thr-70, Ser-83, Ser-101) does not interact with eIF4E; a distinct EB-γ isoform phosphorylated at Thr-70/Ser-83/Ser-101 retains eIF4E binding during mitosis; eIF4E:eIF4G interaction is maintained or increased in mitosis, indicating active translation initiation during mitosis. |
2D gel electrophoresis; proximity ligation assays; phospho-site-specific analysis; single-cell nascent protein synthesis assay; eIF4G RIP-seq |
The Journal of biological chemistry |
Medium |
31201269
|
| 2019 |
O-GlcNAcylation of 4E-BP1 (within a PEST motif) stabilizes 4E-BP1 protein by reducing its ubiquitination and proteasomal degradation; elevated 4E-BP1 in diabetic retina sequesters eIF4E and alters mRNA translation selection; a CUL3-containing E3 ubiquitin ligase complex regulates 4E-BP1 polyubiquitination via the PEST motif. |
Ribosome profiling (retina); O-GlcNAcase inhibitor (Thiamet G); 4E-BP1/2 knockout mice; cycloheximide chase; CUL3 co-immunoprecipitation |
The Journal of biological chemistry |
High |
30733333
|
| 2021 |
4E-BP1 is tethered to mTORC1 via dual binding: its N-terminal RAIP motif and C-terminal TOS motif bind to two separate sites on Raptor, creating avidity-based tethering that orients the central region of intrinsically disordered 4E-BP1 toward the mTOR kinase site. Phosphorylation-induced conformational switching of 4E-BP1 explains the hierarchy of site phosphorylation and the differential rapamycin sensitivity of individual sites; mTORC1 recognizes both free and eIF4E-bound 4E-BP1. |
NMR spectroscopy monitoring of 4E-BP1/Raptor interaction; in vitro phosphorylation assays; structural analysis of intrinsically disordered 4E-BP1 |
Molecular cell |
High |
33852892
|
| 2019 |
4E-BP1 in mTOR-ablated cardiomyocytes inhibits translation initiation; genetic co-ablation of 4E-BP1 with mTOR rescues cardiac apoptosis, heart function, and survival, establishing 4E-BP1 as the key downstream effector of mTOR-dependent cardiomyocyte viability. |
Cardiac-specific double KO (mTOR + 4E-BP1) mice; echocardiography; apoptosis and autophagy assays; pressure overload model |
The Journal of clinical investigation |
High |
20644257
|
| 2013 |
mTOR-independent phosphorylation of 4E-BP1 occurs during muscle contraction (high-frequency electrical stimulation), is associated with release of 4E-BP1 from eIF4E, and is not blocked by the mTOR inhibitor Torin1; MEK/ERK/RSK1 pathway mediates mTOR-independent phosphorylation of eIF4B during contraction. |
In situ electrical stimulation of rat skeletal muscle; Torin1 (mTOR inhibitor) treatment; MEK/ERK/RSK1 inhibitors; Western blot; co-immunoprecipitation |
Cellular signalling |
Medium |
23707523
|
| 2016 |
ERK and p38 MAP kinases decrease 4E-BP1 protein and mRNA expression through induction of the transcription factor Egr-1, which represses the 4e-bp1 promoter; this identifies a new pathway whereby ERK/p38 regulate translational capacity through transcriptional control of 4E-BP1 levels. |
PMA/GM-CSF stimulation; ERK/p38 inhibitors; dominant-negative Egr (ZnEgr) expression; 4e-bp1 promoter reporter assay; Northern and Western blot |
The Journal of biological chemistry |
Medium |
12618431
|
| 2017 |
During mouse oocyte meiotic resumption, CDK1 and mTOR both phosphorylate 4E-BP1 at the spindle; CDK1 acts via phosphorylation and activation of mTOR; pThr70 of 4E-BP1 co-localizes with CDK1 and phospho-mTOR on the spindle; dominant-negative 4E-BP1 impairs translation and causes spindle abnormalities; PLK1 does not phosphorylate 4E-BP1 in this context. |
Immunofluorescence with phospho-site-specific antibodies; dominant-negative 4E-BP1 expression; CDK1/mTOR/PLK1 inhibitors; in vitro translation assay |
Cell cycle |
Medium |
28272965
|
| 2023 |
4E-BP1 expression decreases during human mesenchymal stem cell (hMSC) senescence; 4E-BP1 knockout destabilizes mitochondrial respiration complex III subunits (including UQCRC2), increases mitochondrial ROS, and accelerates senescence; ectopic 4E-BP1 expression rescues these defects in both 4E-BP1-deficient and physiologically aged hMSCs. |
CRISPR-Cas9 4E-BP1 knockout in hMSCs; ectopic overexpression; mitochondrial respiration assay; Western blot for complex III subunits; ROS measurement; senescence assays |
Protein & cell |
Medium |
36929036
|
| 2015 |
Muscle-specific 4E-BP1 transgenic expression directly increases PGC-1α translation and enhances mitochondrial respiratory function; it also promotes FGF21 secretion, preserving brown adipose tissue metabolism and protecting against age- and diet-induced insulin resistance and metabolic decline. |
Transgenic mice with skeletal muscle-specific 4E-BP1 expression; polysome fractionation for PGC-1α translation; metabolic phenotyping; FGF21 ELISA; adipose tissue analysis |
The Journal of clinical investigation |
High |
26121750
|