IFT88 (intraflagellar transport 88; mouse Tg737/polaris; C. elegans OSM-5) is a large tetratricopeptide-repeat (TPR) scaffold protein and a core subunit of the IFT-B1 (core) subcomplex of intraflagellar transport complex B, where it forms part of the IFT88/IFT70/IFT52/IFT46 module. IFT-B polymerises into anterograde IFT trains that are moved from the ciliary base to the tip by heterotrimeric kinesin-2 (KIF3A/KIF3B/KAP3), carrying axonemal and membrane cargo; at the tip trains are remodelled and returned by cytoplasmic dynein-2 with IFT-A. IFT88 accumulates at the basal body/ciliary base (where pre-docked IFT-B is released into the cilium by the CEP19-RABL2 module), along the axoneme and at the ciliary tip, and is required for assembly and maintenance of both primary and motile cilia and flagella. Loss of IFT88 abolishes flagella in Chlamydomonas and causes short or absent primary cilia, polycystic kidney disease, defective Hedgehog signalling and left-right patterning defects in mice; additional mouse studies implicate IFT88 in sperm manchette/flagellum formation and in cilium-dependent autophagy.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0001822 kidney development | IBA GO_REF:0000033 | KEEP AS NON CORE | Summary: Kidney development (IBA). Mouse Tg737/Ift88 hypomorphs develop polycystic kidney disease with short renal primary cilia; this is a downstream organ-level consequence of IFT88's ciliogenesis function. Reason: Phylogenetically supported and consistent with mouse genetics, but the kidney phenotype is a consequence of loss of renal primary cilia rather than a distinct IFT88 activity. Supporting Evidence: PMID:11062270 We show that the primary cilia in the kidney of Tg737 mutant mice are shorter than normal. |
| GO:0002177 manchette | ISS GO_REF:0000024 | KEEP AS NON CORE | Summary: Manchette localization transferred from mouse Ift88 (ISS), where IFT88 localizes to the manchette of elongating spermatids during sperm head shaping and flagellum formation. Reason: Plausible tissue-specific localization in spermatids, based on mouse data; not part of the core ciliary IFT role. |
| GO:0005515 protein binding | IPI PMID:25564561 The kinetochore protein, CENPF, is mutated in human ciliopat... | REMOVE | Summary: IPI with CENP-F (P49454). Endogenous IFT88 and CENP-F reciprocally co-immunoprecipitate in HEK293T cells. Reason: Generic protein binding is uninformative; the interaction itself is not disputed, but it does not identify an IFT88 molecular function. Supporting Evidence: PMID:25564561 Pairwise co-immunoprecipitation assays of mitotic and serum-starved HEKT293 cells confirmed that IFT88 precipitates with endogenous CENP-F |
| GO:0005515 protein binding | IPI PMID:26980730 Overall Architecture of the Intraflagellar Transport (IFT)-B... | REMOVE | Summary: IPI with IFT52 (Q9Y366) from the visible-immunoprecipitation mapping of the IFT-B complex. This interaction reflects IFT88's membership in the IFT-B core (IFT88/IFT70/IFT52/IFT46 module), already captured by the IFT-B complex annotation. Reason: Generic protein binding is uninformative; the IFT-B subunit interaction is better represented by part_of intraciliary transport particle B (GO:0030992), which is annotated from the same paper. Supporting Evidence: PMID:26980730 we determined the overall architecture of the IFT-B complex, which can be divided into core and peripheral subcomplexes composed of 10 and 6 subunits, respectively |
| GO:0005515 protein binding | IPI PMID:27767179 The serologically defined colon cancer antigen-3 (SDCCAG3) i... | REMOVE | Summary: IPI with SDCCAG3/ENTR1 (Q96C92); amino acids 400-550 of IFT88 bind SDCCAG3 by yeast two-hybrid and GST pulldown. Reason: Generic protein binding is uninformative and no specific IFT88 molecular function follows from this interaction. Supporting Evidence: PMID:27767179 Here we show that SDCCAG3 localizes also to primary cilia and interacts with the intraflagellar transport protein IFT88. |
| GO:0005515 protein binding | IPI PMID:30388400 Biallelic Mutations in LRRC56, Encoding a Protein Associated... | REMOVE | Summary: IPI with LRRC56 (Q8IYG6), a protein needed for distal outer dynein arm assembly in motile cilia. Reason: Generic protein binding is uninformative; the interaction suggests a cargo-adaptor relationship but does not by itself define an IFT88 molecular function. Supporting Evidence: PMID:30388400 LRRC56 interacts with the intraflagellar transport (IFT) protein IFT88. |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | REMOVE | Summary: High-throughput binary Y2H interaction (HuRI) with A0A0C4DGQ7. Reason: Generic protein binding from a large-scale binary interactome screen; uninformative about IFT88 function. |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | REMOVE | Summary: High-throughput binary Y2H interaction (HuRI) with P27987 (ITPKB). Reason: Generic protein binding from a large-scale binary interactome screen; uninformative about IFT88 function. |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | REMOVE | Summary: High-throughput binary Y2H interaction (HuRI) with Q969G3. Reason: Generic protein binding from a large-scale binary interactome screen; uninformative about IFT88 function. |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | REMOVE | Summary: High-throughput binary Y2H interaction (HuRI) with Q96G04. Reason: Generic protein binding from a large-scale binary interactome screen; uninformative about IFT88 function. |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | REMOVE | Summary: High-throughput binary Y2H interaction (HuRI) with Q96HB5. Reason: Generic protein binding from a large-scale binary interactome screen; uninformative about IFT88 function. |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | REMOVE | Summary: High-throughput binary Y2H interaction (HuRI) with Q9NZV6. Reason: Generic protein binding from a large-scale binary interactome screen; uninformative about IFT88 function. |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | REMOVE | Summary: High-throughput binary Y2H interaction (HuRI) with Q9Y6W3. Reason: Generic protein binding from a large-scale binary interactome screen; uninformative about IFT88 function. |
| GO:0005737 cytoplasm | IEA GO_REF:0000120 | KEEP AS NON CORE | Summary: Cytoplasm (IEA). IFT88 has a cytoplasmic pool, concentrated around the basal body/centrosome, from which IFT-B is recruited into cilia. Reason: Correct but very general; the specific ciliary-base and basal-body locations are the informative ones. |
| GO:0005737 cytoplasm | ISS GO_REF:0000024 | KEEP AS NON CORE | Summary: Cytoplasm (ISS from mouse Ift88). As above. Reason: Correct but very general parent location. |
| GO:0005813 centrosome | IDA PMID:27767179 The serologically defined colon cancer antigen-3 (SDCCAG3) i... | ACCEPT | Summary: Centrosome (IDA). IFT88 co-localizes with SDCCAG3 at centrosomes and primary cilia. Reason: Direct immunofluorescence evidence; centrosome/basal body is where IFT-B is concentrated before entering the cilium. Supporting Evidence: PMID:27767179 SDCCAG3 and IFT88 both localize at centrosomes and cilia |
| GO:0005813 centrosome | IEA GO_REF:0000120 | ACCEPT | Summary: Centrosome (IEA, UniProt subcellular location). Consistent with the IDA annotation. Reason: Corroborated by IDA (PMID:27767179). |
| GO:0005814 centriole | IBA GO_REF:0000033 | ACCEPT | Summary: Centriole (IBA). IFT88 is concentrated at the mother centriole/basal body and is seen at centrioles in multiple species. Reason: Phylogenetically supported and consistent with experimental centriole/basal-body localization in human cells (PMID:27623382, PMID:25564561). |
| GO:0005814 centriole | IDA PMID:27623382 A Conserved Role for Girdin in Basal Body Positioning and Ci... | ACCEPT | Summary: Centriole (IDA) from a study of Girdin in basal body positioning in C. elegans and RPE-1 cells. The cached abstract does not mention IFT88, but IFT88 is routinely used as a basal body/centriole marker in RPE-1 cells and the curator read the full text. Reason: Deferring to the curator's reading of the full text; centriole/basal-body localization of IFT88 is well established. |
| GO:0005814 centriole | IEA GO_REF:0000120 | ACCEPT | Summary: Centriole (IEA). Consistent with IDA/IBA annotations. Reason: Corroborated by IDA (PMID:27623382) and IBA. |
| GO:0005814 centriole | ISS GO_REF:0000024 | ACCEPT | Summary: Centriole (ISS from mouse Ift88). Consistent with human data. Reason: Corroborated by human IDA. |
| GO:0005829 cytosol | TAS Reactome:R-HSA-9641096 | KEEP AS NON CORE | Summary: Cytosol (TAS, Reactome R-HSA-9641096) from the aggrephagy pathway, where IFT88 is listed among "misfolded cilia proteins" that are ubiquitinated by Parkin. Here IFT88 is a substrate of a quality-control pathway, not an active participant; nevertheless IFT88 does have a genuine cytoplasmic/cytosolic pool. Reason: Cytosolic presence is plausible but the location is not where IFT88 functions; the reactions describe IFT88 as a misfolded substrate. Supporting Evidence: Reactome:R-HSA-9641096 Stress factors damage and misfold cilia proteins, which are then translocated to the cytosol. |
| GO:0005829 cytosol | TAS Reactome:R-HSA-9641109 | KEEP AS NON CORE | Summary: Cytosol (TAS, Reactome aggrephagy reaction R-HSA-9641109); IFT88 as a misfolded ciliary protein substrate. Reason: As for the other aggrephagy-derived cytosol annotations; not a functional location for IFT88. |
| GO:0005829 cytosol | TAS Reactome:R-HSA-9641111 | KEEP AS NON CORE | Summary: Cytosol (TAS, Reactome aggrephagy reaction R-HSA-9641111); IFT88 as a misfolded ciliary protein substrate. Reason: As above. |
| GO:0005829 cytosol | TAS Reactome:R-HSA-9641127 | KEEP AS NON CORE | Summary: Cytosol (TAS, Reactome aggrephagy reaction R-HSA-9641127); IFT88 as a misfolded ciliary protein substrate. Reason: As above. |
| GO:0005829 cytosol | TAS Reactome:R-HSA-9646348 | KEEP AS NON CORE | Summary: Cytosol (TAS, Reactome aggrephagy reaction R-HSA-9646348); IFT88 as a misfolded ciliary protein substrate bound by HDAC6/dynein. Reason: As above. |
| GO:0005829 cytosol | TAS Reactome:R-HSA-9646679 | KEEP AS NON CORE | Summary: Cytosol (TAS, Reactome aggrephagy reaction R-HSA-9646679); IFT88 as a misfolded ciliary protein substrate. Reason: As above. |
| GO:0005829 cytosol | TAS Reactome:R-HSA-9646685 | KEEP AS NON CORE | Summary: Cytosol (TAS, Reactome aggrephagy reaction R-HSA-9646685); IFT88 as a misfolded ciliary protein substrate. Reason: As above. |
| GO:0005856 cytoskeleton | IEA GO_REF:0000044 | KEEP AS NON CORE | Summary: Cytoskeleton (IEA, UniProt subcellular location). Generic parent of the centriole/basal body/axoneme locations. Reason: Correct but uninformative general term. |
| GO:0005929 cilium | IDA GO_REF:0000052 | ACCEPT | Summary: Cilium (IDA, immunofluorescence curation). Reason: IFT88 is a resident IFT-B subunit of cilia, seen within cilia as well as at the ciliary base. Supporting Evidence: PMID:28428259 In the majority of control RPE1 cells, IFT88 is found within cilia as well as at the ciliary base |
| GO:0005929 cilium | IDA PMID:24421332 The CP110-interacting proteins Talpid3 and Cep290 play overl... | ACCEPT | Summary: Cilium (IDA). IFT88 was used as a ciliary marker in Talpid3/Cep290 depletion studies in RPE1 cells. Reason: Direct immunofluorescence of IFT88 in primary cilia. Supporting Evidence: PMID:24421332 we found a significant reduction in primary cilia assembly using four canonical markers, glutamylated tubulin (GT335), detyrosinated tubulin, IFT88, and Arl13b |
| GO:0005929 cilium | IDA PMID:27727273 Zfp423 Regulates Sonic Hedgehog Signaling via Primary Cilium... | ACCEPT | Summary: Cilium (IDA). IFT88 ciliary localization was scored in Zfp423-deficient cerebellar granule precursors. Reason: Consistent with abundant evidence for ciliary IFT88. Supporting Evidence: PMID:27727273 primary cilia abnormalities that include diminished frequency of both Smoothened and IFT88 localization |
| GO:0005929 cilium | IDA PMID:28428259 RABL2 interacts with the intraflagellar transport-B complex ... | ACCEPT | Summary: Cilium (IDA); IFT88 within cilia of RPE1 cells. Reason: Direct immunofluorescence evidence. Supporting Evidence: PMID:28428259 In the majority of control RPE1 cells, IFT88 is found within cilia as well as at the ciliary base |
| GO:0005929 cilium | IEA GO_REF:0000044 | ACCEPT | Summary: Cilium (IEA, UniProt subcellular location). Reason: Corroborated by multiple IDA annotations. |
| GO:0005929 cilium | ISS GO_REF:0000024 | ACCEPT | Summary: Cilium (ISS from mouse Ift88). Reason: Corroborated by human IDA. |
| GO:0005929 cilium | NAS PMID:26980730 Overall Architecture of the Intraflagellar Transport (IFT)-B... | ACCEPT | Summary: Cilium (NAS) from the IFT-B architecture paper. Reason: Correct; IFT-B components localize to cilia. |
| GO:0005929 cilium | TAS Reactome:R-HSA-5624949 | ACCEPT | Summary: Cilium (TAS, Reactome anterograde IFT train assembly). Reason: Correct; IFT88 is a component of anterograde IFT trains within the cilium. Supporting Evidence: Reactome:R-HSA-5624949 Isolation and characterization of IFT particles revealed that they consist of 2 biochemically distinct subcomplexes, IFT A and IFT B |
| GO:0005929 cilium | TAS Reactome:R-HSA-5625416 | ACCEPT | Summary: Cilium (TAS, Reactome anterograde IFT). Reason: Correct. |
| GO:0005929 cilium | TAS Reactome:R-HSA-5625424 | ACCEPT | Summary: Cilium (TAS, Reactome retrograde IFT train dissociation). Reason: Correct. |
| GO:0005929 cilium | TAS Reactome:R-HSA-5625426 | ACCEPT | Summary: Cilium (TAS, Reactome retrograde IFT). Reason: Correct. |
| GO:0019894 kinesin binding | IBA GO_REF:0000033 | ACCEPT | Summary: Kinesin binding (IBA). IFT-B is the complex that couples to the anterograde kinesin-2 motor; early work proposed IFT88 as a link between the IFT particle and kinesin-II. Reason: Phylogenetic inference consistent with IFT-B coupling to kinesin-2; the precise IFT-B subunit(s) contacting kinesin-2 may include others, but the IBA node placement is not contradicted. Supporting Evidence: PMID:11062270 Alternatively, IFT88 may have a vital role in the attachment of the IFT particle to its cargo or to the anterograde IFT motor FLA10-kinesin-II. |
| GO:0030991 intraciliary transport particle A | IDA PMID:26980730 Overall Architecture of the Intraflagellar Transport (IFT)-B... | REMOVE | Summary: Part of IFT-A (IDA) from the IFT-B architecture paper. IFT88 is a canonical IFT-B core subunit, and this paper mapped the IFT-B complex; IFT88 is not an IFT-A subunit (IFT-A = IFT144/WDR19, IFT140, IFT139/TTC21B, IFT122, IFT121/WDR35, IFT43). Reason: Contradicted by the well-established subunit composition of IFT-A and IFT-B; the same paper supports the IFT-B (GO:0030992) annotation, which is retained. This looks like a wrong-complex term choice. Supporting Evidence: PMID:11062270 Complex B is composed of IFT88 and 10 other proteins including IFT172, IFT81, and IFT57 |
| GO:0030992 intraciliary transport particle B | IEA GO_REF:0000117 | ACCEPT | Summary: Part of IFT-B (IEA, ARBA). Reason: Core identity of IFT88. |
| GO:0030992 intraciliary transport particle B | IPI PMID:26980730 Overall Architecture of the Intraflagellar Transport (IFT)-B... | ACCEPT | Summary: Part of IFT-B (IPI). IFT88 is a core IFT-B subunit in the interaction map of the human IFT-B complex. Reason: Core identity; experimentally supported. Supporting Evidence: PMID:26980730 we determined the overall architecture of the IFT-B complex, which can be divided into core and peripheral subcomplexes composed of 10 and 6 subunits, respectively |
| GO:0030992 intraciliary transport particle B | ISS GO_REF:0000024 | ACCEPT | Summary: Part of IFT-B (ISS from mouse). Reason: Core identity. |
| GO:0030992 intraciliary transport particle B | ISS GO_REF:0000024 | ACCEPT | Summary: Part of IFT-B (ISS from Q9FPW0, an IFT88 ortholog). Reason: Core identity; IFT88 was identified as a complex B subunit in Chlamydomonas. Supporting Evidence: PMID:11062270 Complex B is composed of IFT88 and 10 other proteins including IFT172, IFT81, and IFT57 |
| GO:0031514 motile cilium | IEA GO_REF:0000044 | ACCEPT | Summary: Motile cilium (IEA). IFT88 is required for and present in motile cilia/flagella as well as primary cilia. Reason: IFT88 loss abolishes motile flagella in Chlamydomonas; IFT operates in all cilia types. Supporting Evidence: PMID:11062270 Cells that carry at least one copy of wild-type IFT88 have normal flagella and motility, whereas those that carry no copies of wild-type IFT88 lack flagella and are nonmotile |
| GO:0031514 motile cilium | ISS GO_REF:0000024 | ACCEPT | Summary: Motile cilium (ISS from ortholog Q9FPW0). Reason: As above. |
| GO:0034021 response to silicon dioxide | IEA GO_REF:0000107 | REMOVE | Summary: Response to silicon dioxide (IEA, transferred from rat via Ensembl Compara). Derived from an expression/toxicology observation in rat. Reason: No evidence that IFT88 participates in a response to silica; such expression-change annotations do not describe IFT88 function and should not be propagated to human. |
| GO:0035720 intraciliary anterograde transport | NAS PMID:26980730 Overall Architecture of the Intraflagellar Transport (IFT)-B... | ACCEPT | Summary: Intraciliary anterograde transport (NAS). IFT-B trains carry cargo from ciliary base to tip under kinesin-2. Reason: Core process for IFT88 as an IFT-B core subunit. Supporting Evidence: PMID:26980730 IFT is mediated by multisubunit complexes, including IFT-A, IFT-B, and the BBSome, in concert with kinesin and dynein motors |
| GO:0036064 ciliary basal body | IBA GO_REF:0000033 | ACCEPT | Summary: Ciliary basal body (IBA). Reason: Phylogenetically supported and corroborated by multiple human IDA annotations. |
| GO:0036064 ciliary basal body | IDA GO_REF:0000052 | ACCEPT | Summary: Ciliary basal body (IDA, immunofluorescence curation). Reason: IFT88 is a canonical basal body/ciliary base marker. |
| GO:0036064 ciliary basal body | IDA PMID:17604723 HEF1-dependent Aurora A activation induces disassembly of th... | ACCEPT | Summary: Ciliary basal body (IDA) from the HEF1/Aurora A cilium disassembly paper (abstract-only cache; UniProt cites this paper for IFT88 basal body localization). Reason: Deferring to the curator; consistent with abundant evidence. |
| GO:0036064 ciliary basal body | IDA PMID:27767179 The serologically defined colon cancer antigen-3 (SDCCAG3) i... | ACCEPT | Summary: Ciliary basal body (IDA), with SDCCAG3. Reason: Direct evidence. Supporting Evidence: PMID:27767179 SDCCAG3 also localizes to the basal body of primary cilia in RPE cells suggesting a partial overlap between SDCCAG3 and IFT88 localization also in cilia |
| GO:0036064 ciliary basal body | IDA PMID:28428259 RABL2 interacts with the intraflagellar transport-B complex ... | ACCEPT | Summary: Ciliary basal body (IDA), RABL2/CEP19 study. Reason: Direct evidence of IFT88 at the ciliary base. Supporting Evidence: PMID:28428259 In the majority of control RPE1 cells, IFT88 is found within cilia as well as at the ciliary base |
| GO:0036064 ciliary basal body | IDA PMID:28625565 The CEP19-RABL2 GTPase Complex Binds IFT-B to Initiate Intra... | ACCEPT | Summary: Ciliary basal body (IDA). IFT88 colocalizes with RABL2B at the ciliary base, where pre-docked IFT-B is released into the cilium. Reason: Direct super-resolution evidence. Supporting Evidence: PMID:28625565 SIM revealed that IFT88 almost perfectly colocalized with RABL2B at the ciliary base |
| GO:0036064 ciliary basal body | IDA PMID:36606424 CCDC66 regulates primary cilium length and signaling via int... | ACCEPT | Summary: Ciliary basal body (IDA). CCDC66 is required for basal body recruitment of IFT-B machinery. Reason: Direct evidence (abstract-only cache); consistent with abundant evidence. Supporting Evidence: PMID:36606424 CCDC66 is required for the basal body recruitment of transition zone proteins and intraflagellar transport B (IFT-B) machinery |
| GO:0036064 ciliary basal body | IEA GO_REF:0000117 | ACCEPT | Summary: Ciliary basal body (IEA, ARBA). Reason: Corroborated by IDA. |
| GO:0036064 ciliary basal body | ISS GO_REF:0000024 | ACCEPT | Summary: Ciliary basal body (ISS from mouse). Reason: Corroborated by IDA. |
| GO:0036126 sperm flagellum | ISS GO_REF:0000024 | KEEP AS NON CORE | Summary: Sperm flagellum (ISS from mouse Ift88). IFT88 is required for sperm flagellum formation in mouse. Reason: Tissue-specific instance of IFT88's ciliary/flagellar location. |
| GO:0042073 intraciliary transport | IBA GO_REF:0000033 | ACCEPT | Summary: Intraciliary transport (IBA). Reason: Core process; IFT88 is a core IFT-B subunit. Supporting Evidence: PMID:11062270 We cloned and sequenced a Chlamydomonas cDNA encoding the IFT88 subunit of the IFT particle |
| GO:0045724 positive regulation of cilium assembly | IMP PMID:17604723 HEF1-dependent Aurora A activation induces disassembly of th... | MODIFY | Summary: Positive regulation of cilium assembly (IMP), from the HEF1/Aurora A paper (abstract-only). IFT88 is not a regulator of ciliogenesis but a structural component of the IFT-B machinery that builds the cilium; its loss abolishes assembly. Reason: The essence (IFT88 is needed for cilium formation) is sound, but IFT88 is a direct participant in cilium assembly, so cilium assembly (GO:0060271) is the more accurate term than a regulation term. Proposed replacements: cilium assembly Supporting Evidence: PMID:24421332 depletion of IFT88, a protein acting at a later stage in the cilia assembly pathway |
| GO:0060122 inner ear receptor cell stereocilium organization | IBA GO_REF:0000033 | KEEP AS NON CORE | Summary: Inner ear receptor cell stereocilium organization (IBA). Hair-cell planar polarity and stereociliary bundle orientation depend on the kinocilium, which is built by IFT; Ift88 mutant mice show bundle orientation defects. Reason: Downstream developmental consequence of kinocilium assembly; not a distinct IFT88 activity. |
| GO:0060271 cilium assembly | ISS GO_REF:0000024 | ACCEPT | Summary: Cilium assembly (ISS from mouse). Reason: Core process; IFT88 is required for assembly of cilia and flagella in algae and mammals. Supporting Evidence: PMID:11062270 This indicates that IFT is important for primary cilia assembly in mammals. |
| GO:0060271 cilium assembly | NAS PMID:26980730 Overall Architecture of the Intraflagellar Transport (IFT)-B... | ACCEPT | Summary: Cilium assembly (NAS). Reason: Core process. |
| GO:0097542 ciliary tip | IEA GO_REF:0000117 | ACCEPT | Summary: Ciliary tip (IEA, ARBA). IFT trains are remodelled at the ciliary tip and IFT-B accumulates there when retrograde transport fails. Reason: Consistent with IFT-B accumulation at bulged tips when IFT-A is absent (PMID:28428259). Supporting Evidence: PMID:28428259 retrograde trafficking mediated by the IFT-A complex is suppressed, resulting in accumulation of the IFT-B complex at the bulged ciliary tips |
| GO:0097542 ciliary tip | TAS Reactome:R-HSA-5624952 | ACCEPT | Summary: Ciliary tip (TAS, Reactome retrograde IFT train assembly at the tip). Reason: Correct. Supporting Evidence: Reactome:R-HSA-5624952 Remodelling of IFT trains is thought to occur at the ciliary tip |
| GO:0097542 ciliary tip | TAS Reactome:R-HSA-5625416 | ACCEPT | Summary: Ciliary tip (TAS, Reactome anterograde IFT). Reason: Correct. |
| GO:0097542 ciliary tip | TAS Reactome:R-HSA-5625421 | ACCEPT | Summary: Ciliary tip (TAS, Reactome anterograde train dissociation). Reason: Correct. |
| GO:0097542 ciliary tip | TAS Reactome:R-HSA-5625426 | ACCEPT | Summary: Ciliary tip (TAS, Reactome retrograde IFT). Reason: Correct. |
| GO:0097546 ciliary base | IBA GO_REF:0000033 | ACCEPT | Summary: Ciliary base (IBA). Reason: IFT-B pre-docks at the ciliary base before entering cilia. Supporting Evidence: PMID:28625565 SIM revealed that IFT88 almost perfectly colocalized with RABL2B at the ciliary base |
| GO:0097730 non-motile cilium | IBA GO_REF:0000033 | ACCEPT | Summary: Non-motile cilium (IBA). Reason: IFT88 is a resident of primary (non-motile) cilia, as shown in many human cell studies. |
| GO:0120212 sperm head-tail coupling apparatus | ISS GO_REF:0000024 | KEEP AS NON CORE | Summary: Sperm head-tail coupling apparatus (ISS from mouse Ift88). Reason: Tissue-specific location from mouse spermatogenesis studies; not core. |
| GO:1902017 regulation of cilium assembly | IEA GO_REF:0000117 | MODIFY | Summary: Regulation of cilium assembly (IEA, ARBA). IFT88 is a structural part of the assembly machinery rather than a regulator. Reason: Cilium assembly (GO:0060271) is the more accurate representation of IFT88's direct role. Proposed replacements: cilium assembly |
| GO:1902017 regulation of cilium assembly | ISS GO_REF:0000024 | MODIFY | Summary: Regulation of cilium assembly (ISS from mouse). Reason: As above; IFT88 directly builds the cilium as part of IFT-B. Proposed replacements: cilium assembly |
| GO:1905515 non-motile cilium assembly | IBA GO_REF:0000033 | ACCEPT | Summary: Non-motile cilium assembly (IBA). Reason: Core process; IFT88 is required for primary cilium assembly (mouse Tg737 kidney cilia; human RPE1 axonemal elongation). Supporting Evidence: PMID:11062270 This indicates that IFT is important for primary cilia assembly in mammals. |
| GO:2000785 regulation of autophagosome assembly | ISS GO_REF:0000024 | KEEP AS NON CORE | Summary: Regulation of autophagosome assembly (ISS from mouse Ift88), from studies showing cilium/IFT-dependent trafficking of ATG16L to the ciliary base. Reason: Plausible and supported in mouse cells, but a secondary role relative to IFT and ciliogenesis. |
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Download this section (compressed HTML)Q: Which IFT-B subunit(s) physically contact the KIF3A/KIF3B/KAP3 kinesin-2 motor in human cells, and is the IBA "kinesin binding" for IFT88 a direct contact or a complex-level property?
Q: What specific cargoes (e.g. LRRC56-associated dynein arm components, polycystin-2) does the IFT88 TPR superhelix bind directly?
Experiment: Cryo-ET of human anterograde IFT trains combined with crosslinking-MS to map the IFT88 TPR surface that contacts neighbouring IFT-B subunits, kinesin-2 and cargo.
Experiment: Separation-of-function point mutants in IFT88 TPR repeats (preserving IFT-B assembly) to test whether IFT88 binds specific cargo such as LRRC56 or ATG16L1 directly.
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