ArticlePLoS pathogens2014
SUMOylation by the E3 ligase TbSIZ1/PIAS1 positively regulates VSG expression in Trypanosoma brucei.
Article in PLoS pathogens, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 37 papers.
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Who cites it
37 citing papers in PubMed, 59 citations in OpenAlex.
- Specialized RNA decay fine-tunes monogenic antigen expression in Trypanosoma brucei.Nature microbiology · 2026Article
- A factor integrating transcription and repression of surface antigen genes in African trypanosomes.Proceedings of the National Academy of Sciences of the United States of America · 2026Article
- ML-792 impairsFrontiers in cellular and infection microbiology · 2026Article
- Key Regulators of Parasite Biology Viewed Through a Post-Translational Modification Repertoire.Proteomics · 2025Review
- A non-coding role for trypanosome VSG transcripts in allelic exclusion.Nucleic acids research · 2025Article
- Metatranscriptomes-based sequence similarity networks uncover genetic signatures within parasitic freshwater microbial eukaryotes.Microbiome · 2025Article
- Depolymerization of SUMO chains induces slender to stumpy differentiation in T. brucei bloodstream parasites.PLoS pathogens · 2024Article
- Unwrap RAP1's Mystery at Kinetoplastid Telomeres.Biomolecules · 2024Review
- Decoding the impact of nuclear organization on antigenic variation in parasites.Nature microbiology · 2023Review
- Stage-specific transcription activator ESB1 regulates monoallelic antigen expression in Trypanosoma brucei.Nature microbiology · 2022Article
- Article
- An assembly of nuclear bodies associates with the active VSG expression site in African trypanosomes.Nature communications · 2022Article
- Nuclear Condensates: New Targets to Combat Parasite Immune Evasion?Frontiers in cellular and infection microbiology · 2022Article
- Pedal to the Metal: Nuclear Splicing Bodies Turbo-Charge VSG mRNA Production in African Trypanosomes.Frontiers in cell and developmental biology · 2022Review
- DNA double strand break position leads to distinct gene expression changes and regulates VSG switching pathway choice.PLoS pathogens · 2021Article
- A nuclear enterprise: zooming in on nuclear organization and gene expression control in the African trypanosome.Parasitology · 2021Review
- Regulation of Antigenic Variation byPathogens (Basel, Switzerland) · 2021Review
- SUMO and Transcriptional Regulation: The Lessons of Large-Scale Proteomic, Modifomic and Genomic Studies.Molecules (Basel, Switzerland) · 2021Review
- May the Odds Be Ever in Your Favor: Non-deterministic Mechanisms Diversifying Cell Surface Molecule Expression.Frontiers in cell and developmental biology · 2021Review
- Ubiquitin-Like Modifiers: Emerging Regulators of Protozoan Parasites.Biomolecules · 2020Review
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Authors and funding
4 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Bloodstream form trypanosomes avoid the host immune response by switching the expression of their surface proteins between Variant Surface Glycoproteins (VSG), only one of which is expressed at any given time. Monoallelic transcription of the telomeric VSG Expression Site (ES) by RNA polymerase I (RNA pol I) localizes to a unique nuclear body named the ESB. Most work has focused on silencing mechanisms of inactive VSG-ESs, but the mechanisms involved in transcriptional activation of a single VSG-ES remain largely unknown. Here, we identify a highly SUMOylated focus (HSF) in the nucleus of the bloodstream form that partially colocalizes with the ESB and the active VSG-ES locus. SUMOylation of chromatin-associated proteins was enriched along the active VSG-ES transcriptional unit, in contrast to silent VSG-ES or rDNA, suggesting that it is a distinct feature of VSG-ES monoallelic expression. In addition, sequences upstream of the active VSG-ES promoter were highly enriched in SUMOylated proteins. We identified TbSIZ1/PIAS1 as the SUMO E3 ligase responsible for SUMOylation in the active VSG-ES chromatin. Reduction of SUMO-conjugated proteins by TbSIZ1 knockdown decreased the recruitment of RNA pol I to the VSG-ES and the VSG-ES-derived transcripts. Furthermore, cells depleted of SUMO conjugated proteins by TbUBC9 and TbSUMO knockdown confirmed the positive function of SUMO for VSG-ES expression. In addition, the largest subunit of RNA pol I TbRPA1 was SUMOylated in a TbSIZ-dependent manner. Our results show a positive mechanism associated with active VSG-ES expression via post-translational modification, and indicate that chromatin SUMOylation plays an important role in the regulation of VSG-ES. Thus, protein SUMOylation is linked to active gene expression in this protozoan parasite that diverged early in evolution.
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