Affinage · Toxoplasma gondii

PAF1

RNA polymerase II associated Paf1 complex component PAF1 · UniProt A0A125YK22

Annotated
2026-09-10
20 papers in source corpus 1 papers cited in narrative 1 extracted findings

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

In Toxoplasma gondii, PAF1 (the LEO1/Paf1 polymerase-associated factor subunit) has been identified as a component of the GCN5b lysine acetyltransferase 'core complex', which also contains the co-activator ADA2-A, TFIID subunits, and RRM proteins, based on co-immunoprecipitation and proteomics of GCN5b (PMID:24391497). This places PAF1 within a machinery linked to transcriptional and chromatin regulation, but no direct functional experiments on PAF1 itself have been reported in the available corpus.

Mechanistic history

Synthesis pass · year-by-year structured walk · 1 step
  1. 2014 Medium

    To define the composition of the GCN5b acetyltransferase machinery in Toxoplasma, this work established that PAF1/LEO1 associates with a GCN5b 'core complex' alongside ADA2-A, TFIID subunits, and RRM proteins, placing PAF1 in a transcription/chromatin-remodeling context.

    Evidence Co-immunoprecipitation of HA-tagged GCN5b followed by mass spectrometry proteomics in Toxoplasma gondii

    PMID:24391497

    Open questions at the time
    • Single Co-IP/proteomics pulldown; no reciprocal PAF1 pulldown to confirm the interaction
    • No direct functional characterization of PAF1's role within the complex
    • Whether PAF1 is required for GCN5b activity, transcription, or parasite viability is untested

Open questions

Synthesis pass · forward-looking unresolved questions
  • The molecular function of PAF1 itself, its requirement for GCN5b complex integrity or activity, and its role in transcription and chromatin regulation remain uncharacterized.
  • No knockout or knockdown phenotype for PAF1
  • No demonstration of a direct enzymatic or regulatory activity
  • No structural or reciprocal interaction data

Mechanism profile

Synthesis pass · controlled-vocabulary classification
Partners
ADA2-AGCN5BRRM PROTEINSTFIID SUBUNITS
Complex memberships
GCN5b acetyltransferase core complex

Evidence

Reading pass · 1 per-paper finding extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2014 Toxoplasma gondii PAF1 (LEO1 polymerase-associated factor / Paf1 subunit) was identified as a component of the GCN5b acetyltransferase 'core complex' that includes the co-activator ADA2-A, TFIID subunits, LEO1/PAF1, and RRM proteins, as determined by proteomics studies of GCN5b co-immunoprecipitation. Co-immunoprecipitation followed by proteomics (mass spectrometry) of HA-tagged GCN5b PLoS pathogens Medium 24391497

Source papers

Stage 0 corpus · 20 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2016 Dendrimer-RNA nanoparticles generate protective immunity against lethal Ebola, H1N1 influenza, and Toxoplasma gondii challenges with a single dose. Proceedings of the National Academy of Sciences of the United States of America 318 27382155
2016 Id2 reinforces TH1 differentiation and inhibits E2A to repress TFH differentiation. Nature immunology 100 27213691
2014 Lysine acetyltransferase GCN5b interacts with AP2 factors and is required for Toxoplasma gondii proliferation. PLoS pathogens 63 24391497
2011 Protein arginine methylation in parasitic protozoa. Eukaryotic cell 50 21685318
2006 Different neurotropic pathogens elicit neurotoxic CCR9- or neurosupportive CXCR3-expressing microglia. Journal of immunology (Baltimore, Md. : 1950) 49 16951324
2006 Comparison between two real-time PCR assays and a nested-PCR for the detection of Toxoplasma gondii. Acta bio-medica : Atenei Parmensis 49 17172185
1998 Phylogenetic analysis of coccidia based on 18S rDNA sequence comparison indicates that Isospora is most closely related to Toxoplasma and Neospora. The Journal of eukaryotic microbiology 49 9561772
2017 Voltage-dependent calcium channel signaling mediates GABAA receptor-induced migratory activation of dendritic cells infected by Toxoplasma gondii. PLoS pathogens 48 29216332
1992 Physical and genetic mapping of cloned ribosomal DNA from Toxoplasma gondii: primary and secondary structure of the 5S gene. Gene 48 1601300
2005 A novel class of dual-family immunophilins. The Journal of biological chemistry 47 15845546
2017 Induction of Protective Immunity against Toxoplasma gondii in Mice by Nucleoside Triphosphate Hydrolase-II (NTPase-II) Self-amplifying RNA Vaccine Encapsulated in Lipid Nanoparticle (LNP). Frontiers in microbiology 46 28424680
2009 Evidence for a Single Origin of the 35 kb Plastid DNA in Apicomplexans. Protist 45 23196113
1989 Cloning of cDNAs encoding a 28 kilodalton antigen of Toxoplasma gondii. Molecular and biochemical parasitology 45 2710166
1970 The RNA of toxoplasma gondii. Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N.Y.) 44 5414249
2014 Knockout of leucine aminopeptidase in Toxoplasma gondii using CRISPR/Cas9. International journal for parasitology 41 25444863
2003 Pleiotropic effect due to targeted depletion of secretory rhoptry protein ROP2 in Toxoplasma gondii. Journal of cell science 41 12711703
1998 Upstream elements required for expression of nucleoside triphosphate hydrolase genes of Toxoplasma gondii. Molecular and biochemical parasitology 41 9657328
2021 Direct Nanopore Sequencing of mRNA Reveals Landscape of Transcript Isoforms in Apicomplexan Parasites. mSystems 40 33688018
1994 Temporal differences in the expression of mRNA for IL-10 and IFN-gamma in the brains and spleens of C57BL/10 mice infected with Toxoplasma gondii. Parasite immunology 39 7970867
1974 Protection against Toxoplasma gondii in mice immunized with Toxoplasma cell fractions, RNA and synthetic polyribonucleotides. Immunology 38 4215743