Affinage · Toxoplasma gondii

STX12

SNARE domain-containing protein · UniProt S8GE00

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

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

TgStx12 is a SNARE protein of Toxoplasma gondii that localizes to the endosomal-like compartment and functions in the vesicular trafficking required for biogenesis of the parasite's apical secretory organelles (PMID:33082261, PMID:34340555). Conditional ablation studies show that TgStx12 is needed for correct delivery of proteins to the rhoptries and micronemes as well as to the apicoplast, linking endosomal SNARE-mediated transport to the maturation of these organelles (PMID:33082261). Beyond this endosomal localization and organelle-trafficking role, no further mechanistic detail — including specific SNARE partners, cognate vesicle populations, or fusion machinery — has been characterized in the available corpus.

Mechanistic history

Synthesis pass · year-by-year structured walk · 2 steps
  1. 2020 Medium

    It was unknown which trafficking factors support biogenesis of the apical secretory organelles; conditional ablation established TgStx12 as an endosomal SNARE required for protein delivery to rhoptries, micronemes, and the apicoplast.

    Evidence conditional genetic ablation and localization of SNARE proteins with organelle-biogenesis and trafficking readouts in T. gondii

    PMID:33082261

    Open questions at the time
    • no cognate SNARE partners or fusion complex identified
    • the specific transport step (donor and acceptor membranes) is not resolved
    • mechanistic detail beyond phenotypic trafficking defects is limited
  2. 2021 Medium

    A distinct experimental series confirmed that TgStx12, together with TgStx10, resides in the endosome-like compartment, reinforcing its assignment to the endosomal trafficking machinery.

    Evidence fluorescence localization of tagged SNARE proteins and conditional ablation in T. gondii

    PMID:34340555

    Open questions at the time
    • functional relationship between TgStx12 and TgStx10 not defined
    • no reciprocal interaction or complex assembly demonstrated

Open questions

Synthesis pass · forward-looking unresolved questions
  • The molecular SNARE complex in which TgStx12 operates, its cognate vesicle populations, and the precise membrane fusion step it catalyzes remain undefined.
  • no identified SNARE binding partners
  • no structural or biochemical reconstitution
  • mechanism of recruitment to the endosomal compartment unknown

Mechanism profile

Synthesis pass · controlled-vocabulary classification
Partners
TGSTX10 (CO-LOCALIZING SNARE IN THE ENDOSOME-LIKE COMPARTMENT)

Evidence

Reading pass · 2 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2020 TgStx12 (Stx12) localizes to the endosomal-like compartment in Toxoplasma gondii and is involved in trafficking of proteins to the apical secretory organelles rhoptries and micronemes as well as to the apicoplast. Conditional ablation/localization studies of SNARE proteins including Stx12 in T. gondii, with functional readout of organelle biogenesis and protein trafficking defects mBio Medium 33082261
2021 TgStx12 (TgStx10 and TgStx12) localizes to the endosome-like compartment in Toxoplasma gondii, as determined by subcellular localization analysis of SNARE proteins. Fluorescence localization of tagged SNARE proteins; conditional ablation experiments in T. gondii mBio Medium 34340555

Source papers

Stage 0 corpus · 5 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2011 Sec22b regulates phagosomal maturation and antigen crosspresentation by dendritic cells. Cell 253 22153078
2020 The ZIP Code of Vesicle Trafficking in Apicomplexa: SEC1/Munc18 and SNARE Proteins. mBio 32 33082261
2021 The Dissection of SNAREs Reveals Key Factors for Vesicular Trafficking to the Endosome-like Compartment and Apicoplast via the Secretory System in Toxoplasma gondii. mBio 20 34340555
2024 Apical annuli are specialised sites of post-invasion secretion of dense granules in Toxoplasma. eLife 10 38270431
2015 Phosphorylation of αSNAP is Required for Secretory Organelle Biogenesis in Toxoplasma gondii. Traffic (Copenhagen, Denmark) 8 26566590