Affinage · Toxoplasma gondii

IMC27

inner membrane complex protein IMC27 · UniProt S8GC95

Annotated
2026-09-08
2 papers in source corpus 2 papers cited in narrative 2 extracted findings

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

IMC27 is a component of the inner membrane complex (IMC) of Toxoplasma gondii, localizing to the IMC suture subcompartment where it was identified by proximity labeling using the suture protein ISC4 as bait (PMID:27696623). Within the alveolin-based cytoskeletal network of the IMC, IMC27 physically interacts with the essential IMC protein ILP1 through ILP1's C-terminal coiled-coil domain, as captured by in-cell photo-crosslinking and domain mapping (PMID:31584943). Beyond this suture localization and ILP1 interaction, no functional role, essentiality, or downstream mechanism for IMC27 itself has been characterized in the available corpus.

Mechanistic history

Synthesis pass · year-by-year structured walk · 2 steps
  1. 2016 Medium

    Before this work the molecular composition of the IMC suture subcompartment was undefined; BioID from the suture bait ISC4 placed IMC27 in this compartment, establishing it as a suture-associated protein.

    Evidence Proximity-dependent biotin identification (BioID) with ISC4 as bait in Toxoplasma gondii

    PMID:27696623

    Open questions at the time
    • Single bait in one lab; proximity labeling does not distinguish direct from indirect neighbors
    • No functional or knockout follow-up on IMC27 itself
    • Sub-suture localization not resolved
  2. 2019 Medium

    It was unknown which cytoskeletal partners tether IMC27 within the IMC; in-cell photo-crosslinking and domain mapping showed IMC27 binds the essential protein ILP1 via ILP1's C-terminal coiled-coil, integrating IMC27 into the IMC protein-interaction network.

    Evidence Photoactivatable unnatural amino acid crosslinking with mass spectrometry and ILP1 domain-truncation mapping in the native intracellular environment

    PMID:31584943

    Open questions at the time
    • IMC27-specific functional consequence of the interaction not tested
    • Whether the interaction is direct versus bridged not fully resolved
    • Region of IMC27 mediating binding not mapped

Open questions

Synthesis pass · forward-looking unresolved questions
  • The functional role of IMC27 in IMC assembly, stability, or parasite viability remains uncharacterized.
  • No knockout or knockdown phenotype
  • No structural model of IMC27
  • Role in suture formation or daughter cell budding untested

Mechanism profile

Synthesis pass · controlled-vocabulary classification
Partners
ILP1 (VIA ILP1 C-TERMINAL COILED-COIL DOMAIN)ISC4 (PROXIMITY)
Complex memberships
IMC alveolin-based cytoskeletal network / suture subcompartment

Evidence

Reading pass · 2 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2016 IMC27 was identified as a component of the Toxoplasma IMC sutures through proximity-dependent biotin identification (BioID) using ISC4 as bait, placing it within the IMC suture subcompartment. Proximity-dependent biotin identification (BioID) / proximity labeling proteomics Cellular microbiology Medium 27696623
2019 IMC27 physically interacts with the essential IMC protein ILP1 via ILP1's C-terminal coiled-coil domain, as captured by photoactivatable unnatural amino acid crosslinking in the native intracellular environment, placing IMC27 within the cytoskeletal protein-interaction network of the IMC. Photoactivatable unnatural amino acid (UAA) crosslinking followed by mass spectrometry; domain-mapping experiments identifying the ILP1 C-terminal coiled-coil region as the binding interface PLoS biology Medium 31584943

Source papers

Stage 0 corpus · 2 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2016 Novel insights into the composition and function of the Toxoplasma IMC sutures. Cellular microbiology 59 27696623
2019 A photoactivatable crosslinking system reveals protein interactions in the Toxoplasma gondii inner membrane complex. PLoS biology 33 31584943