Disease relevance of EEF2

• Farnesyltransferase inhibitor SCH66336 induces rapid phosphorylation of eukaryotic translation elongation factor 2 in head and neck squamous cell carcinoma cells [1].
• The ability of GA to inhibit the growth of glioma cells was abrogated by overexpressing EF-2 kinase [2].
• Disruption of the EF-2 kinase/Hsp90 protein complex: a possible mechanism to inhibit glioblastoma by geldanamycin [2].
• We have identified two types of mutants of Chinese hamster ovary cells in which the unique ADP-ribose attachment site in elongation factor 2 (EF-2) is altered, thereby rendering them resistant to diphtheria and Pseudomonas toxins (TOXR) [3].
• Muscle atrophy appears to be caused by changes in mRNA levels of specific regulators of proteolysis, protein synthesis, and contractile apparatus assembling, such as polyubiquitin, elongation factor 2, and nebulin [4].

Psychiatry related information on EEF2

• Increased phosphorylation of elongation factor 2 in Alzheimer's disease [5].

High impact information on EEF2

• Proliferating-cell nuclear antigen and c-myc mRNA concentrations and bromodeoxyuridine incorporation were decreased in the EF2-decoy group by medians of 73% [IQR 53-84], 70% [50-79], and 74% [56-83], respectively) but not in the scrambled-oligodeoxynucleotide group (p<0.0001) [6].
• There are two subclasses of cellular enzymes: the ectoenzymes that modify targets such as integrins, defensin and other cell surface molecules; and the intracellular enzymes that act on proteins involved in cell signalling and metabolism, such as the beta-subunit of heterotrimeric G proteins, GRP78/BiP and elongation factor 2 [7].
• The P-protein complex of eukaryotic ribosomes forms a lateral stalk structure in the active site of the large ribosomal subunit and is thought to assist in the elongation phase of translation by stimulating GTPase activity of elongation factor-2 and removal of deacylated tRNA [8].
• Increased phosphorylation of elongation factor 2 during mitosis in transformed human amnion cells correlates with a decreased rate of protein synthesis [9].
• Elongation factor 2 was identified in the two-dimensional gel patterns of asynchronous human amnion cells (AMA) by comigration with purified rabbit reticulocyte elongation factor 2 and by two-dimensional gel immunoblot analysis using a specific rabbit polyclonal antibody [9].

Chemical compound and disease context of EEF2

• Diphtheria toxin and Pseudomonas exotoxin A catalyze the transfer of an ADP-ribose residue from NAD to diphthamide, causing the inactivation of EF-2 [10].
• Two genes (EFT1 and EFT2) were isolated by screening a bacteriophage lambda yeast genomic DNA library with an oligonucleotide probe complementary to the domain of EF-2 that contains diphthamide, the unique posttranslationally modified histidine that is specifically ADP-ribosylated by diphtheria toxin [11].
• Mutations in the elongation factor 2 gene which confer resistance to diphtheria toxin and Pseudomonas exotoxin A. Genetic and biochemical analyses [12].
• On the other hand, the glycohydrolase did not hydrolyze ADP-ribosylated cysteine on the alpha-subunits of pertussis toxin-substrate GTP-binding proteins, ADP-ribosylated diphthamide on elongation factor 2, or ADP-ribosylated asparagine on rho GTP-binding proteins [13].
• Biotin- or digoxigenin-conjugated NAD has been used successfully to label EF-2 by diphtheria toxin, an alpha subunit of G protein by pertussis toxin, and poly(ADP-ribose) synthase through auto-poly(ADP-ribosyl)ation (J. Zhang, unpublished result, 1996) [14].

Biological context of EEF2

• We showed that SCH66336 induced phosphorylation (inactivation) of eukaryotic translation elongation factor 2 (eEF2), an important molecule for protein synthesis, as early as 3 hours after SCH66336 administration [1].
• These facts suggest that the gene encoding EF-2 is located on human chromosome 19 [15].
• The deduced amino-acid sequence of pHGR81, when compared with the known identical amino-acid sequences of hamster as well as rat EF-2 revealed a substitution of a glutamine by an alanine residue in the partially determined human sequence [16].
• Construction of a plasmid containing the complete coding region of human elongation factor 2 [17].
• Indirect immunofluorescent microscopy was used to study the distribution of elongation factor 2 (eEF-2) in fixed human skin diploid and mouse embryo fibroblasts [18].

Anatomical context of EEF2

• It was confirmed by using two-dimensional gel electrophoresis that PA toxin resistance in hybrid cells was caused by the presence of EF-2 resistant to ADP-ribosylation by fragment A of diphtheria toxin [15].
• The use of two primers allowed the specific enzymatic amplification of elongation factor 2 starting with total double-stranded cDNA from human ovarian granulosa cells [19].
• 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 [2].
• Kinetic determination of the effects of ADP-ribosylation on the interaction of eukaryotic elongation factor 2 with ribosomes [20].
• Alcohol Regulates Eukaryotic Elongation Factor 2 Phosphorylation via an AMP-activated Protein Kinase-dependent Mechanism in C2C12 Skeletal Myocytes [21].

Associations of EEF2 with chemical compounds

• In competition studies with Tb(3+), the dissociation rates of Ca(2+) (k(off)) from the EF2 domains of S100B in the absence and presence of the p53 peptide was determined to be 60 and 7 s(-)(1), respectively [22].
• We postulate that this modification system is involved in the conversion of a single histidine residue in EF-2 to the specific target of toxin-catalyzed ADP-ribosylation, the novel amino acid X [3].
• Preliminary results also indicate that the isolated A chain is about an order of magnitude more active in incorporating adenosine diphosphoribose into translocase (elongation factor 2) than whole or nicked toxin is under identical conditions [23].
• NMR spectral analysis of the novel amino acid, diphthamide, in elongation factor 2 which is ADP-ribosylated by diphtheria toxin suggests that it is 2-[3-carboxyamido-3-(trimethylammonio)propyl]histidine [24].
• Furthermore, the addition of nicotinamide, which competes with NAD+ on the DTX action site of EF-2, also blocked DTX-mediated lysis [25].

Physical interactions of EEF2

• S100B is a dimeric Ca(2+)-binding protein that undergoes a 90 +/- 3 degrees rotation of helix 3 in the typical EF-hand domain (EF2) upon the addition of calcium [22].

Regulatory relationships of EEF2

• Mutation of Tyr307 and Leu309 in the protein phosphatase 2A catalytic subunit favors association with the alpha 4 subunit which promotes dephosphorylation of elongation factor-2 [26].
• Other protein synthesis inhibitory proteins act by their ADP-ribosyltransferase activity which modify and thus inactivate elongation factor-2 [27].

Other interactions of EEF2

• Paradoxically, activation of eEF2 kinase (eEF2K), the only known kinase that regulates eEF2, was observed only at 12 hours after SCH66336 treatment [1].
• The corresponding Ca(2+) association rate constants for S100B, k(on), for the EF2 domains in the absence and presence of the p53 peptide are 1.1 x 10(6) and 3.5 x 10(5) M(-)(1) s(-)(1), respectively [22].
• On the other hand, eEF2 and enolase I may be the downstream targets of the MAPK pathway [28].
• Activation of CaM kinase III leads to the selective phosphorylation of elongation factor 2 (eEF-2) and transient inhibition of protein synthesis [29].
• By contrast, U37 is encoded in elongation factor 2 gene [30].

Analytical, diagnostic and therapeutic context of EEF2

• Cloning and sequence analysis of a cDNA from human ovarian granulosa cells encoding the C-terminal part of human elongation factor 2 [16].
• The PCR was used to amplify the elongation factor 2 gene in both the tumor cells and the autologous B cell line, and DNA sequencing of the products revealed the presence of a heterozygous mutation in the tumor cells that accounts for the difference between the two peptide sequences [31].
• By using immunoblotting, immunoprecipitation and comigration assays, we identified one of the rapidly induced proteins (Mr 96,000; pI 6.8) as eukaryotic elongation factor 2 (EF-2), a major component of the protein translation apparatus [32].
• Western blot analysis showed that equal amounts of EF-2 were present in each of the cell strains, indicating that the mutations impaired the catalytic function of EF-2 [12].
• The hamster elongation factor 2 gene was isolated from genomic libraries of diphtheria toxin- and Pseudomonas aeruginosa exotoxin A-resistant cells containing non-ADP-ribosylatable elongation factor 2, and its structure was determined by a combination of restriction endonuclease mapping and DNA sequence analysis [33].

References