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The eukaryotic translation elongation factor 1 (eEF1) family exhibits critical roles in RNA viral infection beyond its canonical function in protein synthesis. This review analyzes the structural characteristics of eEF1A and the eEF1B complex, and their regulatory mechanisms during viral infection. eEF1A impacts viral replication by stabilizing viral RNA-dependent RNA polymerase (RdRp) complexes, modulating genomic RNA synthesis, and facilitating viral assembly through cytoskeletal regulation. eEF1B subunits contribute through enhancing viral mRNA translation, regulating nuclear transport of viral components, and mediating post-translational modifications. The high conservation of eEF1 proteins across species and their involvement in multiple stages of viral replication establish them as promising broad-spectrum antiviral targets. Current eEF1-targeting compounds like plitidepsin demonstrate efficacy against diverse viral families, though therapeutic development faces challenges in balancing antiviral activity with host toxicity. This review provides a theoretical foundation for developing novel antiviral strategies targeting host–virus interaction interfaces and offers insights into addressing emerging infectious diseases.

Up-regulation of utrophin in muscles represents a promising therapeutic strategy for the treatment of Duchenne Muscular Dystrophy. We previously demonstrated that eEF1A2 associates with the 5’UTR of utrophin A to promote IRES-dependent translation. Here, we examine whether eEF1A2 directly regulates utrophin A expression and identify via an ELISA-based high-throughput screen, FDA-approved drugs that upregulate both eEF1A2 and utrophin A. Our results show that transient overexpression of eEF1A2 in mouse muscles causes an increase in IRES-mediated translation of utrophin A. Through the assessment of our screen, we reveal 7 classes of FDA-approved drugs that increase eEF1A2 and utrophin A protein levels. Treatment of mdx mice with the 2 top leads results in multiple improvements of the dystrophic phenotype. Here, we report that IRES-mediated translation of utrophin A via eEF1A2 is a critical mechanism of regulating utrophin A expression and reveal the potential of repurposed drugs for treating DMD via this pathway. One potential approach for the treatment of Duchenne muscular dysrophy is to increase expression of the dystrophin homolog utrophin. Here, the authors show that eEF1A2 regulates utrophin expression, and show that 2 FDA-approved drugs upregulate eEIF1A2 and utrophin level in mice, leading to improvement of the dystrophic phenotype.

Background: Eukaryotic translation elongation factor 1A2 (eEF1A2) is a known proto-oncogene. We proposed that stimulation of the eEF1A2 expression in cancer tissues is caused by the loss of miRNA-mediated control. Methods: Impact of miRNAs on eEF1A2 at the mRNA and protein levels was examined by qPCR and western blot, respectively. Dual-luciferase assay was applied to examine the influence of miRNAs on 3′-UTR of EEF1A2. To detect miRNA-binding sites, mutations into the 3′-UTR of EEF1A2 mRNA were introduced by the overlap extension PCR. Results: miR-663 and miR-744 inhibited the expression of luciferase gene attached to the 3′-UTR of EEF1A2 up to 20% and 50%, respectively. In MCF7 cells, overexpression of miR-663 and miR-744 reduced the EEF1A2 mRNA level by 30% and 50%. Analogous effects were also observed at the eEF1A2 protein level. In resveratrol-treated MCF7 cells the upregulation of mir-663 and mir-744 was accompanied by downregulation of EEF1A2 mRNA. Both miRNAs were able to inhibit the proliferation of MCF7 cells. Conclusion: miR-663 and miR-744 mediate inhibition of the proto-oncogene eEF1A2 expression that results in retardation of the MCF7 cancer cells proliferation. Antitumour effect of resveratrol may include stimulation of the miR-663 and miR-744 expression.

Two years into the pandemic, the COVID-19 drugs pipeline is primed to pump out novel treatments — and fresh uses for familiar therapies. Two years into the pandemic, the COVID-19 drugs pipeline is primed to pump out novel treatments — and fresh uses for familiar therapies.

eEF1A2 is one of the isoforms of the alpha subunit of the eukaryotic Elongation Factor 1. It is overexpressed in human tumors and is endowed with oncogenic properties, favoring tumor cell proliferation while inhibiting apoptosis. We demonstrate that plitidepsin, an antitumor agent of marine origin that has successfully completed a phase-III clinical trial for multiple myeloma, exerts its antitumor activity by targeting eEF1A2. The drug interacts with eEF1A2 with a K D of 80 nM and a target residence time of circa 9 min. This protein was also identified as capable of binding [ 14 C]-plitidepsin in a cell lysate from K-562 tumor cells. A molecular modelling approach was used to identify a favorable binding site for plitidepsin at the interface between domains 1 and 2 of eEF1A2 in the GTP conformation. Three tumor cell lines selected for at least 100-fold more resistance to plitidepsin than their respective parental cells showed reduced levels of eEF1A2 protein. Ectopic expression of eEF1A2 in resistant cells restored the sensitivity to plitidepsin. FLIM-phasor FRET experiments demonstrated that plitidepsin localizes in tumor cells sufficiently close to eEF1A2 as to suggest the formation of drug-protein complexes in living cells. Altogether, our results strongly suggest that eEF1A2 is the primary target of plitidepsin.

Eukaryotic elongation factor 1A (eEF1A), the second most abundant intracellular protein, not only plays a key role in peptide elongation, but is also capable of numerous moonlighting functions. Within malignant cells, eEF1A is by no means a neutral bystander but instead actively participates in oncogenic transformations via a myriad of molecular pathways. Thus far, a broad range of small-molecule inhibitors have been identified, which, despite their structural diversity, suppress tumor growth by targeting eEF1A. Interestingly, just as eEF1A enables its oncogenic potential far beyond boosting protein translation, these targeted agents disrupt this oncoprotein via multiple axes distinct from mere protein synthesis inhibition. Whereas the oncogenic mechanisms of eEF1A has been well documented, there lacks a systemic survey of the eEF1A-targeting agents in terms of their mechanisms. Accordingly, the present work aims to examine their multifaceted modes of action more than just blocking protein synthesis. By unveiling these insights, our deepened knowledge of these eEF1A-binding inhibitors will inform the development of future eEF1A-targeted drugs for cancer treatment.

The natural product didemnin B inhibits PPT1 and the antiapoptotic protein Mcl-1 in particular types of cancer cells containing a unique genetic profile that correlates with drug sensitivity. Modern cancer treatment employs many effective chemotherapeutic agents originally discovered from natural sources. The cyclic depsipeptide didemnin B has demonstrated impressive anticancer activity in preclinical models. Clinical use has been approved but is limited by sparse patient responses combined with toxicity risk and an unclear mechanism of action. From a broad-scale effort to match antineoplastic natural products to their cellular activities, we found that didemnin B selectively induces rapid and wholesale apoptosis through dual inhibition of PPT1 and EEF1A1. Furthermore, empirical discovery of a small panel of exceptional responders to didemnin B allowed the generation of a regularized regression model to extract a sparse-feature genetic biomarker capable of predicting sensitivity to didemnin B. This may facilitate patient selection in a fashion that could enhance and expand the therapeutic application of didemnin B against neoplastic disease.

Cyclic peptide natural products have evolved to exploit diverse protein targets, many of which control essential cellular processes. Inspired by a series of cyclic peptides with partially elucidated structures, we designed synthetic variants of ternatin, a cytotoxic and anti-adipogenic natural product whose molecular mode of action was unknown. The new ternatin variants are cytotoxic toward cancer cells, with up to 500-fold greater potency than ternatin itself. Using a ternatin photo-affinity probe, we identify the translation elongation factor-1A ternary complex (eEF1A·GTP·aminoacyl-tRNA) as a specific target and demonstrate competitive binding by the unrelated natural products, didemnin and cytotrienin. Mutations in domain III of eEF1A prevent ternatin binding and confer resistance to its cytotoxic effects, implicating the adjacent hydrophobic surface as a functional hot spot for eEF1A modulation. We conclude that the eukaryotic elongation factor-1A and its ternary complex with GTP and aminoacyl-tRNA are common targets for the evolution of cytotoxic natural products. Many plants, fungi, and bacteria have evolved to produce small molecules that have powerful effects on the cells of other living organisms, and can even kill them. These naturally produced compounds are often used as starting points for developing new drugs. One such class of compounds are the cyclic peptides, which can be relatively easily produced in the laboratory and are able to penetrate cells. Some cyclic peptides have also proved to be useful for treating cancer and immune diseases, so researchers are keen to identify others that have similar effects. One promising prospect, called ternatin, is produced by several species of fungi. In high doses, ternatin can kill mammalian cells, but it was not clear how it does so. To learn more, Carelli et al. searched a chemical database for cyclic peptides related to ternatin and identified several similar compounds that were reported to kill cancer cells. Inspired by the structures of these cyclic peptides, Carelli et al. synthesized modified versions of ternatin. One of these was 500 times more potent than ternatin, which means a much lower dose of the compound is still able to kill cancer cells. Further experiments showed that ternatin blocks the production of new proteins in cells. Specifically, ternatin binds to a complex that includes a protein called elongation factor-1A (eEF1A). Mutations in a particular region of eEF1A prevent ternatin from killing cells, suggesting a potential binding site for ternatin. The next challenge is to dissect the mechanism by which compounds binding to this site on eEF1A block protein synthesis and kill cells. A related challenge is to understand why certain cancer cells are hypersensitive to ternatin and other eEF1A inhibitors, while other cancer cells are relatively resistant. These questions are relevant to the development of eEF1A inhibitors as cancer treatments.

Hypoxia is a key feature of the tumor microenvironment that leads to the failure of many chemotherapies and induces more aggressive and resistant cancer phenotypes. Up to date, there are very few compounds and treatments that can target hypoxia. BE-43547A from Streptomyces sp. was one of the most hypoxia-selective compounds against PANC-1, MCF-7, and K562 cell lines. In this study, we investigated the molecular mechanism underlying the hypoxia selectivity of BE-43547A in human pancreatic cancer cells. We showed that BE-43547A displayed hypoxia-selective cytotoxicity in five pancreatic cancer cells (PANC-1, Capan-2, MIA PaCa-2, AsPC-1, and PaTu8988T) with IC values under hypoxia considerably lower than those under normoxia. We demonstrated that BE-43547A is directly bound to eEF1A1 protein in PaTu8988T cells under hypoxia. Furthermore, we revealed that hypoxia significantly elevated the expression levels of HIF1α, FoxO1, and eEF1A1 in the five pancreatic cancer cells; eEF1A1 interacted with FoxO1 in the cytoplasm, which was disrupted by BE-43547A followed by the nuclear translocation of FoxO1 and ultimate inhibition of JAK/STAT3 signaling pathway under hypoxia. This study reveals that BE-43547A , targeting eEF1A1, disrupts its interaction with FoxO1 in human pancreatic cancer cells under hypoxia. This compound could serve as a potential hypoxia-selective therapy.

Legionella pneumophila, the causal agent of Legionnaires' disease, is an intracellular parasite and invades and proliferates within different eukaryotic cells, including human alveolar macrophages. After several 100-fold multiplication within host cells, the pathogens are released for new invasion by induction of apoptosis or necrosis. Here we report that L. pneumophila produces a glucosyltransferase, which selectively modifies an ᅈ50-kDa mammalian protein by using UDP-glucose as a cosubstrate. MS analysis identified the protein substrate as the mammalian elongation factor (EF)1A. Legionella glucosyltransferase modifies its eukaryotic protein substrate at serine-53, which is located in the GTPase domain of the EF. Glucosylation of EF1A results in inhibition of eukaryotic protein synthesis and death of target cells. Our findings show a mode of inhibition of protein synthesis by microbial pathogens and offer a perspective for understanding of the host-pathogen interaction of L. pneumophila.