Affinage · Plasmodium

EIF5A

PF3D7_1204300 · eukaryotic translation initiation factor 5A

Annotated
2026-09-08
26 papers in source corpus 9 papers cited in narrative 11 extracted findings

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

EIF5A (PF3D7_1204300) is a translation factor whose activity in Plasmodium depends on an essential two-step post-translational modification, hypusination, that is required for asexual blood-stage proliferation (PMID:22694849, PMID:31024761). Recombinant P. falciparum EIF5A serves as the direct acceptor substrate for deoxyhypusine synthase (DHS), which transfers an aminobutyl moiety from spermidine to the EIF5A precursor (PMID:15279952, PMID:17591443), after which P. falciparum DOHH hydroxylates the deoxyhypusine intermediate to complete formation of the mature hypusine residue (PMID:19740108). This modification depends on intracellular spermidine: pharmacological depletion of spermidine suppresses EIF5A protein levels (PMID:19949824), and genetic disruption of spermidine biosynthesis abolishes hypusination and kills the parasite (PMID:40531988). Hypusinated EIF5A is functionally required for parasite proliferation—in vivo silencing in P. berghei eliminates the hypusinated form and reduces parasitemia (PMID:22694849), and the gene is refractory to knockout, consistent with essentiality for asexual blood-stage development (PMID:27516964). Attenuation of the upstream modifying enzyme DHS reduces hypusinated EIF5A and causes a growth defect without affecting global protein synthesis, indicating that hypusinated EIF5A regulates translation of specific mRNAs rather than bulk protein production (PMID:31024761). Beyond its role as the hypusinated substrate in this pathway, the specific mRNA targets and translational mechanism of EIF5A have not been characterized in the available corpus.

Mechanistic history

Synthesis pass · year-by-year structured walk · 10 steps
  1. 2004 Medium

    Establishing that P. falciparum encodes a bona fide hypusination substrate answered whether the parasite possesses the eIF5A/hypusine axis at all.

    Evidence cDNA cloning, recombinant His-tagged expression, and in vitro [3H]spermidine incorporation with human DHS

    PMID:15279952

    Open questions at the time
    • Used human DHS rather than the parasite enzyme
    • Did not identify the modified lysine position
    • No cellular function established
  2. 2004 Low

    Transcript profiling asked whether EIF5A expression is stage-restricted, showing it is constitutively transcribed across the erythrocytic cycle.

    Evidence Quantitative real-time PCR of synchronized ring, trophozoite, and schizont stages

    PMID:15279952

    Open questions at the time
    • Transcript-level only, no protein or activity correlation
    • No functional consequence tested
  3. 2007 Medium

    Demonstrating modification by the parasite's own DHS confirmed EIF5A is the direct endogenous substrate of plasmodial deoxyhypusine synthase, not merely of a heterologous enzyme.

    Evidence Recombinant P. vivax EIF5A modified in vitro by truncated P. falciparum NF54 DHS, Western blot with anti-eIF5A antiserum

    PMID:17591443

    Open questions at the time
    • Substrate protein was P. vivax ortholog, not P. falciparum EIF5A directly
    • Full-length DHS not used
    • No in-parasite validation
  4. 2008 Low

    Proteomic detection of multiple EIF5A isoforms asked whether the protein is post-translationally modified in vivo, consistent with hypusination during development.

    Evidence 2D-DIGE and mass spectrometry of schizont-stage P. falciparum across a synchronized time-course

    PMID:19091060

    Open questions at the time
    • Isoform differences not molecularly assigned to hypusination
    • No functional readout
  5. 2009 Medium

    Identifying DOHH activity on EIF5A resolved the second enzymatic step, placing EIF5A hydroxylation downstream of DHS and completing the hypusine pathway.

    Evidence In vitro DOHH hydroxylase assay on EIF5A deoxyhypusine substrate

    PMID:19740108

    Open questions at the time
    • In vitro reconstitution only
    • No demonstration that DOHH step is rate-limiting or essential in the parasite
  6. 2009 Low

    Linking spermidine availability to EIF5A levels placed polyamine metabolism upstream of EIF5A maturation in the parasite.

    Evidence SAM486A (AdoMetDC inhibitor) treatment of P. falciparum cultures, 2D gels, Western blot, polyamine quantification

    PMID:19949824

    Open questions at the time
    • Indirect via upstream enzyme inhibition
    • Did not distinguish loss of hypusination from loss of total protein
  7. 2012 Medium

    In vivo silencing tested whether hypusinated EIF5A is actually required for parasite growth, showing loss of the hypusinated form and reduced parasitemia.

    Evidence shRNA silencing in transgenic P. berghei schizonts, murine infection, RT-PCR, Western blot

    PMID:22694849

    Open questions at the time
    • Knockdown, not clean loss-of-function
    • Mechanism connecting EIF5A to iNOS induction unclear
    • Specific mRNA targets not identified
  8. 2016 Medium

    Reverse genetics asked whether EIF5A is dispensable, and the failure to obtain a knockout established it as essential for asexual blood-stage development.

    Evidence Targeted disruption and knock-in in P. berghei with selection and genotyping

    PMID:27516964

    Open questions at the time
    • Essentiality inferred from failed disruption rather than conditional depletion
    • No stage-specific requirement mapped
  9. 2019 Medium

    Conditional attenuation of the modifying enzyme addressed whether hypusinated EIF5A acts globally or specifically in translation, revealing a growth defect without impaired bulk protein synthesis.

    Evidence glmS riboswitch knockdown of PfDHS, hypusination assay, nascent protein synthesis assay, competitive growth assay in P. falciparum

    PMID:31024761

    Open questions at the time
    • Perturbs DHS rather than EIF5A directly
    • Specific target mRNAs not identified
    • No structural or ribosome-profiling data
  10. 2025 Medium

    Genetic disruption of spermidine biosynthesis confirmed that EIF5A hypusination is a critical downstream function of spermidine and that its loss is lethal to the parasite.

    Evidence Genetic disruption of spermidine biosynthesis, hypusination assay, viability and ROS measurement in P. falciparum

    PMID:40531988

    Open questions at the time
    • Spermidine has functions beyond EIF5A that could contribute to lethality
    • Direct causal separation of hypusination loss from other spermidine effects not established

Open questions

Synthesis pass · forward-looking unresolved questions
  • The specific mRNAs whose translation depends on hypusinated EIF5A, and the molecular basis of that selectivity, remain unidentified.
  • No target mRNA set defined
  • No structural model of EIF5A-ribosome interaction
  • No mapping of the modified lysine in the parasite protein

Mechanism profile

Synthesis pass · controlled-vocabulary classification
Partners
DEOXYHYPUSINE HYDROXYLASE (DOHH) — HYDROXYLATES EIF5A DEOXYHYPUSINE IN THE SECOND STEP [#2]DEOXYHYPUSINE SYNTHASE (DHS) — MODIFIES EIF5A IN THE FIRST HYPUSINATION STEP [#0, #1, #7]

Evidence

Reading pass · 11 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2004 A cDNA encoding P. falciparum EIF5A was cloned and expressed as a His-tagged fusion protein in E. coli; radioactive incorporation studies with [1,8-3H] spermidine demonstrated that the recombinant protein can serve as a substrate for human deoxyhypusine synthase (DHS), establishing its role as the acceptor protein in hypusine biosynthesis. cDNA cloning, recombinant protein expression, in vitro radioactive spermidine incorporation assay with human DHS Molecular and biochemical parasitology Medium 15279952
2007 Recombinant EIF5A from P. vivax (97% amino acid identity to P. falciparum EIF5A) was expressed and purified, and shown to be modified in vitro by a truncated recombinant DHS from P. falciparum NF54, confirming EIF5A as the direct substrate of plasmodial DHS in the first step of hypusine biosynthesis. Recombinant protein expression, Nickel affinity chromatography purification, in vitro DHS modification assay, Western blot with anti-eIF5A antiserum Bioorganic & medicinal chemistry Medium 17591443
2009 Recombinant DOHH from P. falciparum was shown by in vitro enzymatic assay to hydroxylate deoxyhypusine in EIF5A, completing the two-step hypusine modification of EIF5A (DHS acting first, DOHH acting second). In vitro DOHH hydroxylase activity assay with EIF5A substrate; enzymatic studies documented via MINT interaction database The FEBS journal Medium 19740108
2008 Mass spectrometry identification of protein spots from 2D-DIGE analysis of schizont-stage P. falciparum revealed that EIF5A is represented by more than one isoform with different expression patterns, indicating it undergoes post-translational modifications during intra-erythrocytic development. 2D differential gel electrophoresis (2D-DIGE), mass spectrometry protein identification, synchronized culture time-course Genome biology Low 19091060
2009 Treatment of P. falciparum in vitro cultures with 10 µM SAM486A (an AdoMETDC inhibitor that depletes spermidine) suppressed EIF5A protein levels as detected by 2D gel electrophoresis and Western blot, establishing that intracellular spermidine availability is required upstream of EIF5A hypusination in the parasite. In vitro P. falciparum culture drug treatment, 2D gel electrophoresis, Western blot, intracellular polyamine quantification Amino acids Low 19949824
2012 In vivo silencing of P. berghei EIF5A via expressed shRNA in transgenic schizonts resulted in absence of hypusinated EIF5A (confirmed by Western blot) and reduced parasitemia, demonstrating that hypusinated EIF5A is required for proliferation of the malaria parasite during blood-stage infection; the hypusine pathway was also linked to host iNOS induction. shRNA-mediated gene silencing in transgenic Plasmodium schizonts, murine infection model, RT-PCR, Western blot BMC microbiology Medium 22694849
2016 Targeted gene disruption of EIF5A in P. berghei was not achievable (full knockout not obtained); instead, only episome-carrying parasites were recovered, and knock-in of the endogenous EIF5A gene yielded viable recombinant parasites, indicating EIF5A is essential for asexual blood-stage development. Targeted gene disruption and knock-in strategy in Plasmodium berghei, selection and genotyping of transgenic parasites FEBS open bio Medium 27516964
2019 Attenuation of PfDHS (the enzyme that catalyzes the first step of EIF5A hypusination) by glmS riboswitch in transgenic P. falciparum led to a significant reduction of hypusinated EIF5A protein (assessed by hypusination assay) without affecting global protein synthesis, and caused a significant parasite growth defect, supporting that hypusinated EIF5A has a specific rather than global role in translation. glmS riboswitch conditional knockdown, Western blot, hypusination assay, nascent protein synthesis assay, competitive growth assay in P. falciparum PeerJ Medium 31024761
2025 In P. falciparum, spermidine is indispensable for hypusination of EIF5A and thereby for regulating protein translation; depletion of spermidine (via disruption of spermidine biosynthesis) leads to parasite death, demonstrating that EIF5A hypusination is a critical downstream function of spermidine in intraerythrocytic development. Genetic disruption of spermidine biosynthesis, hypusination assay, parasite viability assay, reactive oxygen species measurement Science advances Medium 40531988
2007 EIF5A transcription in P. vivax was detected in both trophozoite and ring developmental stages, indicating the gene is expressed throughout the erythrocytic cycle. Transcription analysis of staged parasite cultures (developmental stage assessment) Bioorganic & medicinal chemistry Low 17591443
2004 Quantitative real-time PCR of synchronized erythrocytic stages of P. falciparum showed no significant induction or downregulation of EIF5A mRNA across ring, trophozoite, and schizont stages, indicating the gene is constitutively transcribed without major stage-specific variation. Quantitative real-time PCR on synchronized P. falciparum cultures Molecular and biochemical parasitology Low 15279952

Source papers

Stage 0 corpus · 26 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2008 Quantitative protein expression profiling reveals extensive post-transcriptional regulation and post-translational modifications in schizont-stage malaria parasites. Genome biology 99 19091060
2018 Polyamines in protozoan pathogens. The Journal of biological chemistry 36 30333232
2003 Targeting enzymes involved in spermidine metabolism of parasitic protozoa--a possible new strategy for anti-parasitic treatment. Parasitology research 25 14530966
2008 The guanylhydrazone CNI-1493: an inhibitor with dual activity against malaria-inhibition of host cell pro-inflammatory cytokine release and parasitic deoxyhypusine synthase. Parasitology research 23 18256853
2007 Modification of eukaryotic initiation factor 5A from Plasmodium vivax by a truncated deoxyhypusine synthase from Plasmodium falciparum: An enzyme with dual enzymatic properties. Bioorganic & medicinal chemistry 20 17591443
2015 A novel inhibitor of Plasmodium falciparum spermidine synthase: a twist in the tail. Malaria journal 16 25651815
2004 Translation initiation factor eIF-5A from Plasmodium falciparum. Molecular and biochemical parasitology 15 15279952
2013 Deoxyhypusine hydroxylase from Plasmodium vivax, the neglected human malaria parasite: molecular cloning, expression and specific inhibition by the 5-LOX inhibitor zileuton. PloS one 14 23505486
2012 In vitro and in vivo silencing of plasmodial dhs and eIf-5a genes in a putative, non-canonical RNAi-related pathway. BMC microbiology 13 22694849
2009 Completing the hypusine pathway in Plasmodium. The FEBS journal 13 19740108
2009 Assessment of deoxyhypusine hydroxylase as a putative, novel drug target. Amino acids 13 19956997
2006 Structural and mechanistic insights into the action of Plasmodium falciparum spermidine synthase. Bioorganic & medicinal chemistry 13 17196392
2015 New insights into novel inhibitors against deoxyhypusine hydroxylase from plasmodium falciparum: compounds with an iron chelating potential. Amino acids 12 25715757
2006 Piperidones with activity against Plasmodium falciparum. Parasitology research 12 16550432
2009 Down-regulation of hypusine biosynthesis in Plasmodium by inhibition of S-adenosyl-methionine-decarboxylase. Amino acids 11 19949824
2020 Inhibition of EIF-5A prevents apoptosis in human cardiomyocytes after malaria infection. Amino acids 9 32367435
2019 Validation of Plasmodium falciparum deoxyhypusine synthase as an antimalarial target. PeerJ 9 31024761
2016 A suggested vital function for eIF-5A and dhs genes during murine malaria blood-stage infection. FEBS open bio 9 27516964
2013 Chemical profiling of deoxyhypusine hydroxylase inhibitors for antimalarial therapy. Amino acids 8 23943044
2006 Inhibition of hypusine biosynthesis in plasmodium: a possible, new strategy in prevention and therapy of malaria. Mini reviews in medicinal chemistry 8 17100634
2003 Spermidine metabolism in parasitic protozoa--a comparison to the situation in prokaryotes, viruses, plants and fungi. Folia parasitologica 7 12735718
2011 A rapid and robust assay for the determination of the amino acid hypusine as a possible biomarker for a high-throughput screening of antimalarials and for the diagnosis and therapy of different diseases. Amino acids 6 21360085
2025 Spermidine is a key polyamine required by intracellular parasites for survival within host erythrocytes. Science advances 5 40531988
2023 An Undefined Interaction between Polyamines and Heat Shock Proteins Leads to Cellular Protection in Plasmodium falciparum and Proliferating Cells in Various Organisms. Molecules (Basel, Switzerland) 5 36838674
2024 An experimental target-based platform in yeast for screening Plasmodium vivax deoxyhypusine synthase inhibitors. PLoS neglected tropical diseases 2 39621767
2022 Investigation of an Allosteric Deoxyhypusine Synthase Inhibitor in P. falciparum. Molecules (Basel, Switzerland) 0 35458660