| 2000 |
The C-terminal region of eIF2Bε (residues 518–712 in yeast) is required for both catalytic GEF activity and interaction with eIF2, while the N-terminal half is an activation domain that mediates enhancement of nucleotide exchange rate upon eIF2B complex formation. Missense mutations in the N-terminal region impair complex formation-stimulated activity without affecting basal GEF activity of eIF2Bε alone. |
In vitro GEF assays, in-frame deletion and missense mutation analysis of yeast eIF2Bε (GCD6), binding assays with eIF2B subunits and eIF2 |
Molecular and cellular biology |
High |
10805739
|
| 2001 |
DYRK1A and DYRK2 phosphorylate eIF2Bε at Ser539 (rat; equivalent Ser535 context), and this phosphorylation primes the subsequent inhibitory phosphorylation of Ser535 by GSK3 in vitro. eIF2Bε is highly phosphorylated at Ser539 in vivo, establishing a two-kinase sequential phosphorylation cascade that inhibits eIF2Bε GEF activity. |
In vitro kinase assays with recombinant DYRK isoforms and GSK3; phospho-specific immunoblotting; in vivo phosphorylation confirmed by metabolic labeling |
The Biochemical journal |
High |
11311121
|
| 2002 |
During sepsis, eIF2B kinase activity is elevated and eIF2Bε Ser535 phosphorylation is increased ~2–2.5-fold, correlating with reduced eIF2B GEF activity and impaired skeletal muscle protein synthesis. GSK3 phosphorylation (Ser9, inactivating) is decreased, consistent with activated GSK3 driving eIF2Bε phosphorylation. TNF-binding protein treatment prevents these changes, implicating TNF in the pathway. |
Phospho-specific immunoblotting in rat gastrocnemius; eIF2B kinase/phosphatase activity assays; pharmacological inhibition with TNF-binding protein |
American journal of physiology. Endocrinology and metabolism |
Medium |
12376332
|
| 2005 |
EIF2B5 is required for the generation of GFAP+ astrocytes from glial progenitors. RNAi knockdown of EIF2B5 in normal human glial progenitors severely compromised induction of GFAP+ cells, and cultures from a VWM patient with EIF2B5 mutations produced few morphologically normal astrocytes despite normal oligodendrocyte generation. |
RNAi knockdown of EIF2B5 in primary human glial progenitors; immunocytochemistry for GFAP; primary cell cultures from VWM patient brain |
Nature medicine |
High |
15723074
|
| 2008 |
A splice-site mutation in EIF2B5 causing exon 6 deletion abolishes detectable protein from that allele and severely reduces eIF2B GEF activity, demonstrating that the non-catalytic domain encoded by exon 6 is required for eIF2B complex formation and activity. |
RT-PCR of patient lymphoblastoid cells; eIF2B GEF activity assay; protein detection by immunoblot |
Annals of human genetics |
Medium |
18294360
|
| 2008 |
Resistance exercise reduces phosphorylation of eIF2Bε at Ser540 in human skeletal muscle, suggesting exercise-induced activation of eIF2B GEF activity contributes to stimulation of muscle protein synthesis. |
Muscle biopsy; phospho-specific immunoblotting in young men under fasted/fed and exercise/rest conditions |
American journal of physiology. Regulatory, integrative and comparative physiology |
Medium |
18565837
|
| 2010 |
Ectopic expression of eIF2Bε in rat tibialis anterior increased eIF2B GEF activity, and expression of eIF2Bε in septic rats rescued the deficit in eIF2B GEF activity and skeletal muscle protein synthesis, demonstrating that eIF2Bε expression level is rate-limiting for GEF activity and protein synthesis in skeletal muscle. |
Plasmid transfection into rat tibialis anterior in vivo; GEF activity assay; [3H]phenylalanine incorporation to measure protein synthesis |
American journal of physiology. Endocrinology and metabolism |
High |
20484009
|
| 2013 |
DYRK2 acts as a priming kinase for GSK3β-mediated inhibitory phosphorylation of eIF2Bε in cardiomyocytes. siRNA knockdown of DYRK2 decreased p(S535)-eIF2Bε levels, while adenoviral overexpression of DYRK2 increased eIF2Bε phosphorylation. Constitutively active eIF2Bε-S535A (non-phosphorylatable) promoted cardiac hypertrophy, whereas DYRK2 overexpression reduced cardiomyocyte size and diminished hypertrophic response. |
siRNA knockdown; adenoviral overexpression in cultured cardiomyocytes; transgenic mice with cardiac-specific eIF2Bε or eIF2Bε-S535A; immunoblotting; cardiomyocyte size measurement; isoproterenol treatment and aortic banding |
PloS one |
High |
24023715
|
| 2013 |
The C-terminal catalytic domain of human eIF2Bε expressed in yeast has GEF activity, and CACH/VWM disease mutations within this domain reduce its GEF activity, as measured in a reconstituted assay with purified human eIF2 and human eIF2Bε C-terminal domain. |
Recombinant protein purification from yeast; in vitro GEF assay; comparison of wild-type and disease-mutant forms |
PloS one |
High |
23335982
|
| 2016 |
eIF2Bε is a downstream effector of the AKT-GSK3β signaling axis in CNS axon regeneration. Constitutive activation of eIF2Bε is sufficient to promote axon regeneration after optic nerve injury, and inactivation of eIF2Bε reduces both GSK3β- and AKT-mediated axon regeneration. This pathway acts independently of mTORC1. |
Conditional knockout and constitutively active knock-in alleles of eIF2Bε in mouse retinal ganglion cells; optic nerve crush injury model; axon counting; epistasis by genetic double mutants |
eLife |
High |
26974342
|
| 2017 |
Under hypoxia, intron retention in EIF2B5 creates a premature termination codon producing a 65 kDa truncated eIF2Bε isoform that opposes full-length eIF2Bε and inhibits global translation. Hypoxia-induced SRSF3 binding and increased phospho-Ser2 RNA Pol II at the retained intron promote its retention. Expression of the 65 kDa isoform increases cell survival under hypoxia. |
RNA-seq; RT-PCR; western blot to detect truncated protein; overexpression of truncated isoform; polysome profiling/translation assays; RIP for SRSF3; ChIP for RNA Pol II modifications |
PLoS biology |
High |
28961236
|
| 2019 |
The Eif2b5 p.Ile98Met mutation in mice decreases eIF2B guanine nucleotide exchange activity on eIF2, elevates ATF4 (integrated stress response marker), and causes neurological defects including epilepsy and shortened lifespan, establishing loss of GEF activity as the proximate biochemical defect in VWM. |
GEF activity assay on brain extracts; ATF4 immunoblotting; behavioral and histological analysis of spontaneous mutant mouse |
Journal of neurochemistry |
Medium |
31587290
|
| 2020 |
Intron 12 retention in zebrafish eif2b5 leads to expression of a truncated eif2b5 transcript; forced expression of this truncated form in wild-type zebrafish impairs motor behavior and activates the integrated stress response (ISR), implicating a feed-forward ISR activation as part of VWM pathophysiology. |
Zebrafish eif2b5 mutant characterization; mRNA injection of truncated eif2b5 into wild-type larvae; ISR reporter assays; motor behavior assays |
eLife |
Medium |
33300869
|
| 2021 |
eIF2Bε is required for Wnt-mediated clonogenicity and the associated increase in global translational capacity in intestinal epithelial cells. Using eIF2BεArg191His dysfunctional mice, eIF2Bε loss impairs crypt formation, stemness marker expression, and Paneth cell granule formation; Wnt hyperactivation by GSK3β inhibition requires eIF2Bε for clonogenic expansion. |
Eif2b5 Arg191His knock-in mice; intestinal organoid culture; GSK3β inhibitor treatment; immunofluorescence; polysome/translation capacity assays |
Stem cell research |
Medium |
34399164
|
| 2025 |
Cell-type-specific conditional Eif2b5 mutation in oligodendrocytes (but not neurons) recapitulates the major motor phenotype of VWM mice, with unmyelinated axons, immature cycling oligodendrocytes, and reactive astrocytes. Astrocyte-specific Eif2b5 mutation causes vacuolization and elevated ATF4 transcriptome but only mild ataxia. This establishes oligodendrocytes as the primary cell type driving ataxia in VWM, while astrocytes drive ISR/ATF4 pathology. |
Cell type-specific Cre-driven conditional Eif2b5 knock-in mice (astrocyte-, oligodendrocyte-, neuron-specific); motor behavior testing; immunohistochemistry; myelin/axon analysis; ATF4 transcriptome analysis |
Brain : a journal of neurology |
High |
40326783
|
| 2025 |
EIF2B5 directly interacts with ribosomal protein RPL6 (identified by mass spectrometry and confirmed by co-immunoprecipitation), and EIF2B5 overexpression promotes RPL6 expression and activates the PI3K/AKT/mTOR pathway, driving HCC cell proliferation and invasion. |
Mass spectrometry; co-immunoprecipitation; western blot; siRNA knockdown; overexpression; mouse ectopic tumor assay |
Cellular signalling |
Medium |
40246131
|