Affinage · Toxoplasma gondii

AP2IX7

AP2 domain transcription factor AP2IX-7 · UniProt S8GHU6

Annotated
2026-09-10
10 papers in source corpus 2 papers cited in narrative 2 extracted findings

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

AP2IX-7 is an ApiAP2 transcription factor in Toxoplasma gondii implicated in GCN5b-mediated epigenetic gene regulation (PMID:31381949). Reciprocal co-immunoprecipitation coupled to mass spectrometry places AP2IX-7 in a physical association with the lysine acetyltransferase GCN5b and additional AP2 factors, defining it as a component of at least two distinct GCN5b-containing complexes (PMID:31381949). Beyond this complex membership (PMID:31381949) and a cell cycle-timed expression pattern (PMID:20865045), the specific target genes and direct functional role of AP2IX-7 have not been characterized in the available corpus.

Mechanistic history

Synthesis pass · year-by-year structured walk · 2 steps
  1. 2010 Low

    It was unknown whether AP2IX-7 expression was constitutive or dynamically regulated; profiling across the tachyzoite cell cycle established that its mRNA and protein peak sharply within a defined cell cycle window, framing its activity as temporally gated.

    Evidence Genome-wide transcriptional profiling with protein expression analysis across the tachyzoite cell cycle

    PMID:20865045

    Open questions at the time
    • No direct functional manipulation of AP2IX-7 to test the significance of its cyclical expression
    • The promoter targets and DNA-binding specificity of the AP2 domain were not defined
    • Cell cycle stage of the expression peak inferred from population profiling, not single-cell resolution
  2. 2019 Medium

    The molecular context of AP2IX-7 was unresolved until reciprocal Co-IP mass spectrometry showed it physically associates with the essential acetyltransferase GCN5b and other AP2 factors in at least two distinct multisubunit complexes, placing it within an epigenetic gene-regulatory machinery.

    Evidence Reciprocal co-immunoprecipitation followed by mass spectrometry proteomics in T. gondii

    PMID:31381949

    Open questions at the time
    • Direct target genes of AP2IX-7 within the GCN5b complexes are not identified
    • Whether AP2IX-7 recruits GCN5b to chromatin or is recruited by it is undetermined
    • Functional consequence of complex membership was not tested by genetic ablation

Open questions

Synthesis pass · forward-looking unresolved questions
  • The direct functional role of AP2IX-7 — its genomic binding sites, target genes, and the phenotypic consequence of its loss — remains undefined.
  • No knockout or conditional-depletion phenotype reported
  • No ChIP or genome-wide DNA-binding map for AP2IX-7
  • The distinct roles of the two GCN5b complexes containing AP2IX-7 are not resolved

Mechanism profile

Synthesis pass · controlled-vocabulary classification
Partners
GCN5BOTHER APIAP2 FACTORS
Complex memberships
GCN5b lysine acetyltransferase complex (at least two distinct GCN5b-containing complexes)

Evidence

Reading pass · 2 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2019 AP2IX-7 (AP2IX7) was identified as a component of a GCN5b lysine acetyltransferase complex in Toxoplasma gondii. Reciprocal co-immunoprecipitation of AP2IX-7 delineated its interactome, showing it associates with GCN5b and other AP2 factors as part of at least two distinct GCN5b-containing complexes involved in epigenetic gene regulation. Co-immunoprecipitation (reciprocal Co-IP) followed by mass spectrometry proteomics Molecular and biochemical parasitology Medium 31381949
2010 AP2IX-7 mRNA and protein show a cyclical expression pattern during the tachyzoite cell cycle, with a sharp peak of protein expression in a defined timeframe, suggesting its activity is timed by AP2 domain promoter recognition specificities during cell cycle progression. Genome-wide transcriptional profiling and protein expression analysis across the tachyzoite cell cycle PloS one Low 20865045

Source papers

Stage 0 corpus · 10 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2010 Coordinated progression through two subtranscriptomes underlies the tachyzoite cycle of Toxoplasma gondii. PloS one 234 20865045
2018 The Epigenome, Cell Cycle, and Development in Toxoplasma. Annual review of microbiology 51 29932347
2010 The construction and use of log-odds substitution scores for multiple sequence alignment. PLoS computational biology 48 20657661
2012 Cactin is essential for G1 progression in Toxoplasma gondii. Molecular microbiology 23 22486860
2014 Distinct strains of Toxoplasma gondii feature divergent transcriptomes regardless of developmental stage. PloS one 22 25393307
2019 A novel GCN5b lysine acetyltransferase complex associates with distinct transcription factors in the protozoan parasite Toxoplasma gondii. Molecular and biochemical parasitology 20 31381949
2008 New eukaryotic systematics: a phylogenetic perspective of developmental gene expression in the Apicomplexa. International journal for parasitology 12 18983845
2024 Apicomplexan mitoribosome from highly fragmented rRNAs to a functional machine. Nature communications 9 39690155
2022 Genomic insights into host and parasite interactions during intracellular infection by Toxoplasma gondii. PloS one 2 36178892
2026 Host-cell dependent epigenetic profiles associated with survival outcomes in T. gondii infection. Epigenetics & chromatin 0 42087241