Disease relevance of Eef2

• The ability of GA to inhibit the growth of glioma cells was abrogated by overexpressing EF-2 kinase [1].
• Disruption of the EF-2 kinase/Hsp90 protein complex: a possible mechanism to inhibit glioblastoma by geldanamycin [1].
• Pseudomonas exotoxin A is a single chain toxin with three structural domains that inhibits protein synthesis in eukaryotic cells by catalyzing ADP ribosylation of elongation factor 2 [2].
• The 133,000 X g supernatant fraction prepared from ascites cells in 20 mM KCl (low CKl supernatant) contained the initiation factors EIF-1 and EIF-2 (and the elongation factore EF-1 and EF-2) but lacked EIF-3; thus, low KCl supernatant could be used to assay for EIF-3 [3].
• Elongation factor 2 (EF-2) from S. acidocaldarius was cloned in E. coli and the expressed gene product was used in order to adsorb all anti-EF-2 antibodies which do not contain the ADP-ribosyl group within their epitopes, as E. coli is unable to synthesize the ADP-ribosyl acceptor diphthamide [4].

High impact information on Eef2

• We previously showed that a chromosome 6 locus, IgK-Ef2, controls a pair of prominent bands in normal mouse light-chain isoelectric focusing profiles [5].
• Yeast dph2 mutants are resistant to diphtheria toxin, which catalyses ADP ribosylation of EF-2 at diphthamide [6].
• Phosphorylation of eEF2 halts protein synthesis and may prepare cells to translate a new set of mRNAs [7].
• N-methyl-D-aspartate receptor activation and visual activity induce elongation factor-2 phosphorylation in amphibian tecta: a role for N-methyl-D-aspartate receptors in controlling protein synthesis [7].
• Diphtheria toxin (DT), a bacterial protein exotoxin, inactivates mammalian cell elongation factor 2 after toxin internalization by receptor-mediated endocytosis [8].

Chemical compound and disease context of Eef2

• The translation elongation factor 2 in eukaryotes (eEF-2) contains a unique posttranslationally modified histidine residue, termed diphthamide, which serves as the only target for diphtheria toxin and Pseudomonas aeruginosa exotoxin A [9].
• Mechanism of action of Pseudomonas aeruginosa exotoxin A in experimental mouse infections: adenosine diphosphate ribosylation of elongation factor 2 [10].
• Pseudomonas toxin was assayed by measurement of its ability to catalyze the transfer of radioactivity from [14C]adenine-labeled nicotinamide adenine dinucleotide to elongation factor 2 (adenosine diphosphate ribosylation activity) [11].

Biological context of Eef2

• We also show that the phosphorylation of eEF-2 and the activity of eEF-2K are insulin-regulated in adipocytes [12].
• The mouse genome contains one copy of the functional gene for elongation factor 2 (EF2) per haploid genome and multiple copies of the EF2-related gene [13].
• Simplified cosmid vectors for gene transfer to cultured mammalian cells: isolation of the gene for elongation factor 2 from the mouse [13].
• A major group of mouse kappa chains controlled by the chromosome 6 locus, IgK-Ef2 [14].
• We also found a group of nuclear factors, collectively called delta EF2, which bound to the 5'-located positive element. delta EF2a and -b were the major species in lens cells, whereas delta EF2c and -d predominated in nonlens cells [15].

Anatomical context of Eef2

• Treatment of cell lines for 24-48 h of GA or 17-AAG disrupted EF-2-kinase/Hsp90 interactions as measured by coimmunoprecipitation, resulting in a decreased amount of recoverable kinase in cell lysates [1].
• All are resistant due to a defect in the process of internalization and delivery of toxin to its target in the cytosol, elongation factor 2 [16].
• Fibroblast attachment to EF-2 and EF-4 was mediated by syndecan-2 [17].
• Thus, a high polyribosomes/monomers ratio and both increased proteolysis and decreased ADP-ribosylatable concentration of elongation factor 2 (EF-2) were shown [18].
• Domain I is responsible for cell recognition, II for translocation of PE across membranes and III for ADP ribosylation of elongation factor 2 [19].

Associations of Eef2 with chemical compounds

• Glutamate-dependent phosphorylation of elongation factor-2 and inhibition of protein synthesis in neurons [20].
• 2-Deoxyglucose and NMDA inhibit protein synthesis in neurons and regulate phosphorylation of elongation factor-2 by distinct mechanisms [21].
• We propose that Mg(2+) binding at EF-2 may structurally bridge DREAM to DNA targets and that Ca(2+)-induced protein dimerization disrupts DNA binding [22].
• Here we present structural and binding studies on single-site mutants of DREAM designed to disable Ca(2+) binding to each of the functional EF-hands (EF-2: D150N; EF-3: E186Q; and EF-4: E234Q) [22].
• In the present structure-function analysis, deletion of EF1 and EF2 of the N-terminal four EF-hand domains caused marked reduction of phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2)-hydrolyzing activity in vitro and loss of Ca2+ oscillation-inducing activity in mouse eggs after injection of RNA encoding the mutant [23].

Physical interactions of Eef2

• Antibodies to this epitope blocked the ADP-ribosyltransferase activity of ETA and appeared to interfere with binding of the substrate elongation factor 2 to the enzymatic active site of the ETA molecule [24].

Enzymatic interactions of Eef2

• The elongation factor-2 (eEF-2) is selectively phosphorylated by the eEF-2 kinase (calmodulin-dependent kinase III) [25].

Regulatory relationships of Eef2

• Prothymosin alpha stimulates Ca2+-dependent phosphorylation of elongation factor 2 in cellular extracts [26].

Other interactions of Eef2

• Additional isoforms of the translation elongation factors Eef2 and Eef1a1 were induced [27].
• Neither group showed any change in total eIF2alpha, phosphorylated eukaryotic elongation factor 2 or total eukaryotic elongation factor 2 levels [28].
• The phosphorylation state of phospholamban, troponin inhibitor, and eukaryotic elongation factor 2 was reduced significantly [29].
• The histidine derivative diphthamide occurs uniquely in eukaryotic elongation factor 2 (EF-2), and is the specific target for the diphtheria toxin mono(ADP-ribosyl)transferase [30].

Analytical, diagnostic and therapeutic context of Eef2

• Western blotting analysis confirmed that the 100 kDa protein was EF-2 [31].
• One of these loci, IgK-Ef2, was shown to control two major bands in normal light chain isoelectric focusing (IF) profiles [14].
• Moreover, eEF2 phosphorylation is induced by visual stimulation, and NMDAR blockade before stimulation eliminates this effect [7].
• Isothermal titration calorimetry (ITC) analysis of Ca(2+) binding to the various mutants revealed that, in the absence of Mg(2+), Ca(2+) binds independently and sequentially to EF-3 (DeltaH = -2.4 kcal/mol), EF-4 (DeltaH = +5.2 kcal/mol), and EF-2 (DeltaH = +1 kcal/mol) [22].
• Quantitative Southern blotting analysis has demonstrated that mouse cells contain about 70 copies per haploid genome of a DNA sequence related to the gene for elongation factor 2 [32].

References