Evidence map›Paper›PMID 40053537›Full record

ArticlePloS one2025

Trypanosomes lack a canonical EJC but possess an UPF1 dependent NMD-like pathway.

Bernardo Papini Gabiatti, Eden Ribeiro Freire, Johanna Odenwald, Janaina de Freitas Nascimento, Fabiola Holetz, Mark Carrington, Susanne Kramer, Martin Zoltner

Abstract read
In one paragraph

Article in PloS one, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Article
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors.

Bernardo Papini GabiattiDepartment of Cell and Developmental Biology, University of Würzburg, Würzburg, Germany.
Eden Ribeiro FreireDepartment of Biochemistry, Cambridge University, Cambridge, United Kingdom.
Johanna OdenwaldDepartment of Cell and Developmental Biology, University of Würzburg, Würzburg, Germany.
Janaina de Freitas NascimentoDepartment of Biochemistry, Cambridge University, Cambridge, United Kingdom.
Fabiola HoletzCarlos Chagas Institute (ICC), FIOCRUZ/PR, Curitiba, Brazil.
Mark CarringtonDepartment of Biochemistry, Cambridge University, Cambridge, United Kingdom.
Susanne KramerDepartment of Cell and Developmental Biology, University of Würzburg, Würzburg, Germany.
Martin ZoltnerDepartment of Parasitology, Faculty of Science, Charles University in Prague, Biocev, Vestec, Czech Republic.ORCID https://orcid.org/0000-0002-0214-285X

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

The exon junction complex (EJC) is a key player in metazoan mRNA quality control and is placed upstream of the exon-exon junction after splicing. Its inner core is composed of Magoh, Y14, eIF4AIII and BTZ and the outer core of proteins involved in mRNA splicing (CWC22), export (Yra1), translation (PYM) and nonsense mediated decay (NMD, UPF1/2/3). Trypanosoma brucei encodes only two genes with introns, but all mRNAs are processed by trans-splicing. The presence of three core EJC proteins and a potential BTZ homologue (Rbp25) in trypanosomes has been suggested to adapt of the EJC function to mark trans-spliced mRNAs. We analysed trypanosome EJC components and noticed major differences between eIF4AIII and Magoh/Y14: (i) whilst eIF4AIII is essential, knocking out both Magoh and Y14 elicits only a mild growth phenotype (ii) eIF4AIII localization is mostly nucleolar, while Magoh and Y14 are nucleolar and nucleoplasmic but excluded from the cytoplasm (iii) eIF4AIII associates with nucleolar proteins and the splicing factor CWC22, but not with Y14 or Magoh, while Magoh and Y14 associate with each other, but not with eIF4AIII, CWC22 or nucleolar proteins. Our data argue against the presence of a functional EJC in trypanosomes, but indicate that eIF4AIII adopted non-EJC related, essential functions, while Magoh and Y14 became redundant. Trypanosomes also possess homologues to the NMD proteins UPF1 and UPF2. Depletion of UPF1 causes only a minor reduction in growth and phylogenetic analyses show several independent losses of UPF1 and UPF2, as well as complete loss of UPF3 in the Kinetoplastida group, indicating that UPF1-dependent NMD is not essential. Regardless, we demonstrate that UPF1 depletion restores the mRNA levels of a PTC reporter. Altogether, we show that the almost intron-less trypanosomes are in the process of losing the canonical EJC/NMD pathways: Y14 and Magoh have become redundant and the still-functional UPF1-dependent NMD pathway is not essential.

Indexed as

Nonsense Mediated mRNA DecayProtozoan ProteinsRNA HelicasesTrypanosoma brucei bruceiEukaryotic Initiation Factor-4AExonsRNA, MessengerRNA SplicingEukaryotic Initiation Factor-4AProtozoan ProteinsRNA HelicasesRNA, Messenger

Identifiers

PMID40053537
PMCPMC11888146

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.