IFT122 notes

Summary

IFT122 is a core-subcomplex subunit of IFT-A (IFT122/IFT140/IFT144 core; IFT43/IFT121/IFT139 periphery).
- Subcomplex architecture: PMID:27932497
- Linchpin role: PMID:29220510
- Ciliogenesis: IFT122 KO is unusual among IFT-A subunits PMID:29220510
- Membrane cargo import with TULP3: PMID:20889716; structure PMID:36775821
- Hedgehog: PMID:20889716
- Disease: cranioectodermal dysplasia 1 (UniProt).

Curation decisions

• protein binding (IPI, IFT-A partners / HIV AP-MS / IFTAP): REMOVE as uninformative; IFT-A membership captured by GO:0030991.
• Mouse ISS developmental terms (neural tube closure, limb, heart tube, eye, D/V patterning): KEEP_AS_NON_CORE; embryonic body morphogenesis and intracellular signal transduction MARK_AS_OVER_ANNOTATED.
• NK-cell membrane HDA: MARK_AS_OVER_ANNOTATED.
• Intraciliary anterograde transport IDA (20889716, 40472089): ACCEPT; IFT-A mediates ciliary entry of membrane cargo. The 40472089 full text only shows TULP3-dependent GPR45 entry and cites IFT-A as the TULP3 partner PMID:40472089; deferred to curator.
• protein carrier activity (contributes_to): ACCEPT, core (GO now labels GO:0140597 "protein carrier chaperone").

HPA cilium atlas vs module role

• HPA v25 (Hansen et al. 2025, PMID:41005307): Primary cilium transition zone (Supported); main locations Cytosol; Mid piece; Primary cilium transition zone.
• Module (primary_cilium_life_cycle, stage 4 axoneme_extension_ift): IFT-A subunit, process intraciliary retrograde transport, function "IFT cargo adaptor", location non-motile cilium.
• Assessment: consistent. Transition-zone/base staining fits IFT-A docking and train assembly at the ciliary base; the antibody does not resolve the axonemal pool. core_functions match the module (retrograde IFT, cargo import with TULP3) and add cilium assembly, because IFT122 KO abolishes ciliogenesis. One point to note: the module lists only retrograde transport for IFT-A, but IFT122/IFT-A also mediates membrane-protein entry (PMID:27932497). The role_description covers this.

Deep research

See below.
Falcon deep research succeeded (IFT122-deep-research-falcon.md). It is consistent with the review:
- [file:human/IFT122/IFT122-deep-research-falcon.md "It joins IFT-A subassemblies, helps incorporate IFT-A into intraflagellar transport trains and provides part of the binding surface for the membrane-cargo adaptor TULP3."]
- It also reports IFT-A/IFT-B coupling via IFT122-IFT144 and IFT88-IFT52 (Kobayashi 2021, not cached), and that IFT122 CED mutants mislocalize ARL13B and INPP5E (not used for annotations).