KIFAP3 (kinesin-associated protein 3, KAP3; also called SMAP) is the non-motor accessory subunit of heterotrimeric kinesin-2. It is an armadillo-repeat protein that binds the C-terminal tail domains of the KIF3A/KIF3B motor heterodimer to form the KIF3A/KIF3B/KAP3 complex, and it links the motor to cargo, including membranous organelles, IFT trains in cilia, and N-cadherin-containing carriers. KIFAP3 has no motor domain or ATPase activity of its own. Through kinesin-2 it participates in anterograde intraflagellar transport and cilium assembly, localizing to the basal body, transition zone, axoneme and ciliary tip, and in plus-end-directed vesicle transport in the cytoplasm and neurons. KAP3 also interacts with regulators including the phosphatase POPX2 (which controls KIF3A phosphorylation) and the small-GTPase regulator RAP1GDS1/SmgGDS, and has been reported on mitotic spindles and chromosomes.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0000794 condensed nuclear chromosome | IDA PMID:16298999 Role of the kinesin-2 family protein, KIF3, during mitosis. | KEEP AS NON CORE | Summary: condensed nuclear chromosome (IDA). Reason: Kinesin-2 is reported with spindle microtubules and KAP3 with chromosomes in mitosis; a secondary, less established role. Supporting Evidence: PMID:16298999 the kinesin-2 complex is localized with components of the mitotic apparatus such as spindle microtubules and centrosomes PMID:9506951 The results suggest that SMAP/KAP3 serves as a linker between HCAP and KIF3A/B in the nucleus, and that SMAP/KAP3 plays a role in the interaction of chromosomes with an ATPase motor protein. |
| GO:0001750 photoreceptor outer segment | IEA GO_REF:0000107 | KEEP AS NON CORE | Summary: photoreceptor outer segment (from mouse). Reason: Photoreceptor/periciliary localization transferred from mouse Kifap3, a cell-type-specific instance of its ciliary localization. Supporting Evidence: PMID:32386558 Molecular motor activity is driven by a heterotrimeric complex comprised of KIF3A and KIF3B or KIF3C plus one non-motor subunit, KIFAP3. |
| GO:0001917 photoreceptor inner segment | IEA GO_REF:0000107 | KEEP AS NON CORE | Summary: photoreceptor inner segment (from mouse). Reason: Photoreceptor/periciliary localization transferred from mouse Kifap3, a cell-type-specific instance of its ciliary localization. Supporting Evidence: PMID:32386558 Molecular motor activity is driven by a heterotrimeric complex comprised of KIF3A and KIF3B or KIF3C plus one non-motor subunit, KIFAP3. |
| GO:0005515 protein binding | IPI PMID:16298999 Role of the kinesin-2 family protein, KIF3, during mitosis. | MODIFY | Summary: Interaction with KIF3A/KIF3B motor subunits. Reason: Interaction of KIFAP3 with the kinesin-2 motor subunits KIF3A/KIF3B. For KAP3 this interaction is its defining molecular function: it binds the KIF3A/KIF3B tail domains to form the heterotrimeric motor. 'Protein binding' is uninformative; the more specific term kinesin binding (GO:0019894) is appropriate and already supported by IPI for the same pairs. Proposed replacements: kinesin binding Supporting Evidence: file:human/KIFAP3/KIFAP3-uniprot.txt Binds to the tail domain of the KIF3A/KIF3B heterodimer to form a heterotrimeric KIF3 complex and may regulate the membrane binding of this complex PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. |
| GO:0005515 protein binding | IPI PMID:16298999 Role of the kinesin-2 family protein, KIF3, during mitosis. | MODIFY | Summary: Interaction with KIF3A/KIF3B motor subunits. Reason: Interaction of KIFAP3 with the kinesin-2 motor subunits KIF3A/KIF3B. For KAP3 this interaction is its defining molecular function: it binds the KIF3A/KIF3B tail domains to form the heterotrimeric motor. 'Protein binding' is uninformative; the more specific term kinesin binding (GO:0019894) is appropriate and already supported by IPI for the same pairs. Proposed replacements: kinesin binding Supporting Evidence: file:human/KIFAP3/KIFAP3-uniprot.txt Binds to the tail domain of the KIF3A/KIF3B heterodimer to form a heterotrimeric KIF3 complex and may regulate the membrane binding of this complex PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. |
| GO:0005515 protein binding | IPI PMID:21516116 Next-generation sequencing to generate interactome datasets. | REMOVE | Summary: Protein binding with UniProtKB:P19878 from high-throughput screens. Reason: Generic protein binding from a high-throughput interaction screen. 'Protein binding' is uninformative and no more specific molecular function is supported by this screen alone. Removal does not mean the interaction is false. |
| GO:0005515 protein binding | IPI PMID:24338362 POPX2 phosphatase regulates the KIF3 kinesin motor complex. | MODIFY | Summary: Interaction with KIF3A/KIF3B motor subunits. Reason: Interaction of KIFAP3 with the kinesin-2 motor subunits KIF3A/KIF3B. For KAP3 this interaction is its defining molecular function: it binds the KIF3A/KIF3B tail domains to form the heterotrimeric motor. 'Protein binding' is uninformative; the more specific term kinesin binding (GO:0019894) is appropriate and already supported by IPI for the same pairs. Proposed replacements: kinesin binding Supporting Evidence: file:human/KIFAP3/KIFAP3-uniprot.txt Binds to the tail domain of the KIF3A/KIF3B heterodimer to form a heterotrimeric KIF3 complex and may regulate the membrane binding of this complex PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. |
| GO:0005515 protein binding | IPI PMID:25416956 A proteome-scale map of the human interactome network. | REMOVE | Summary: Protein binding with UniProtKB:P19878 from high-throughput screens. Reason: Generic protein binding from a high-throughput interaction screen. 'Protein binding' is uninformative and no more specific molecular function is supported by this screen alone. Removal does not mean the interaction is false. |
| GO:0005515 protein binding | IPI PMID:25416956 A proteome-scale map of the human interactome network. | REMOVE | Summary: Protein binding with UniProtKB:P41227 from high-throughput screens. Reason: Generic protein binding from a high-throughput interaction screen. 'Protein binding' is uninformative and no more specific molecular function is supported by this screen alone. Removal does not mean the interaction is false. |
| GO:0005515 protein binding | IPI PMID:25910212 Widespread macromolecular interaction perturbations in human... | REMOVE | Summary: Protein binding with UniProtKB:P19878 from high-throughput screens. Reason: Generic protein binding from a high-throughput interaction screen. 'Protein binding' is uninformative and no more specific molecular function is supported by this screen alone. Removal does not mean the interaction is false. |
| GO:0005515 protein binding | IPI PMID:26496610 A human interactome in three quantitative dimensions organiz... | MODIFY | Summary: Interaction with KIF3A/KIF3B motor subunits. Reason: Interaction of KIFAP3 with the kinesin-2 motor subunits KIF3A/KIF3B. For KAP3 this interaction is its defining molecular function: it binds the KIF3A/KIF3B tail domains to form the heterotrimeric motor. 'Protein binding' is uninformative; the more specific term kinesin binding (GO:0019894) is appropriate and already supported by IPI for the same pairs. Proposed replacements: kinesin binding Supporting Evidence: file:human/KIFAP3/KIFAP3-uniprot.txt Binds to the tail domain of the KIF3A/KIF3B heterodimer to form a heterotrimeric KIF3 complex and may regulate the membrane binding of this complex PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. |
| GO:0005515 protein binding | IPI PMID:26496610 A human interactome in three quantitative dimensions organiz... | MODIFY | Summary: Interaction with KIF3A/KIF3B motor subunits. Reason: Interaction of KIFAP3 with the kinesin-2 motor subunits KIF3A/KIF3B. For KAP3 this interaction is its defining molecular function: it binds the KIF3A/KIF3B tail domains to form the heterotrimeric motor. 'Protein binding' is uninformative; the more specific term kinesin binding (GO:0019894) is appropriate and already supported by IPI for the same pairs. Proposed replacements: kinesin binding Supporting Evidence: file:human/KIFAP3/KIFAP3-uniprot.txt Binds to the tail domain of the KIF3A/KIF3B heterodimer to form a heterotrimeric KIF3 complex and may regulate the membrane binding of this complex PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. |
| GO:0005515 protein binding | IPI PMID:26871637 Widespread Expansion of Protein Interaction Capabilities by ... | REMOVE | Summary: Protein binding with UniProtKB:P19878 from high-throughput screens. Reason: Generic protein binding from a high-throughput interaction screen. 'Protein binding' is uninformative and no more specific molecular function is supported by this screen alone. Removal does not mean the interaction is false. |
| GO:0005515 protein binding | IPI PMID:27173435 An organelle-specific protein landscape identifies novel dis... | MODIFY | Summary: Interaction with KIF3A/KIF3B motor subunits. Reason: Interaction of KIFAP3 with the kinesin-2 motor subunits KIF3A/KIF3B. For KAP3 this interaction is its defining molecular function: it binds the KIF3A/KIF3B tail domains to form the heterotrimeric motor. 'Protein binding' is uninformative; the more specific term kinesin binding (GO:0019894) is appropriate and already supported by IPI for the same pairs. Proposed replacements: kinesin binding Supporting Evidence: file:human/KIFAP3/KIFAP3-uniprot.txt Binds to the tail domain of the KIF3A/KIF3B heterodimer to form a heterotrimeric KIF3 complex and may regulate the membrane binding of this complex PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. |
| GO:0005515 protein binding | IPI PMID:27173435 An organelle-specific protein landscape identifies novel dis... | MODIFY | Summary: Interaction with KIF3A/KIF3B motor subunits. Reason: Interaction of KIFAP3 with the kinesin-2 motor subunits KIF3A/KIF3B. For KAP3 this interaction is its defining molecular function: it binds the KIF3A/KIF3B tail domains to form the heterotrimeric motor. 'Protein binding' is uninformative; the more specific term kinesin binding (GO:0019894) is appropriate and already supported by IPI for the same pairs. Proposed replacements: kinesin binding Supporting Evidence: file:human/KIFAP3/KIFAP3-uniprot.txt Binds to the tail domain of the KIF3A/KIF3B heterodimer to form a heterotrimeric KIF3 complex and may regulate the membrane binding of this complex PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. |
| GO:0005515 protein binding | IPI PMID:28514442 Architecture of the human interactome defines protein commun... | MODIFY | Summary: Interaction with KIF3A/KIF3B motor subunits. Reason: Interaction of KIFAP3 with the kinesin-2 motor subunits KIF3A/KIF3B. For KAP3 this interaction is its defining molecular function: it binds the KIF3A/KIF3B tail domains to form the heterotrimeric motor. 'Protein binding' is uninformative; the more specific term kinesin binding (GO:0019894) is appropriate and already supported by IPI for the same pairs. Proposed replacements: kinesin binding Supporting Evidence: file:human/KIFAP3/KIFAP3-uniprot.txt Binds to the tail domain of the KIF3A/KIF3B heterodimer to form a heterotrimeric KIF3 complex and may regulate the membrane binding of this complex PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. |
| GO:0005515 protein binding | IPI PMID:28514442 Architecture of the human interactome defines protein commun... | MODIFY | Summary: Interaction with KIF3A/KIF3B motor subunits. Reason: Interaction of KIFAP3 with the kinesin-2 motor subunits KIF3A/KIF3B. For KAP3 this interaction is its defining molecular function: it binds the KIF3A/KIF3B tail domains to form the heterotrimeric motor. 'Protein binding' is uninformative; the more specific term kinesin binding (GO:0019894) is appropriate and already supported by IPI for the same pairs. Proposed replacements: kinesin binding Supporting Evidence: file:human/KIFAP3/KIFAP3-uniprot.txt Binds to the tail domain of the KIF3A/KIF3B heterodimer to form a heterotrimeric KIF3 complex and may regulate the membrane binding of this complex PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. |
| GO:0005515 protein binding | IPI PMID:31515488 Extensive disruption of protein interactions by genetic vari... | REMOVE | Summary: Protein binding with UniProtKB:P19878 from high-throughput screens. Reason: Generic protein binding from a high-throughput interaction screen. 'Protein binding' is uninformative and no more specific molecular function is supported by this screen alone. Removal does not mean the interaction is false. |
| GO:0005515 protein binding | IPI PMID:31515488 Extensive disruption of protein interactions by genetic vari... | REMOVE | Summary: Protein binding with UniProtKB:P41227 from high-throughput screens. Reason: Generic protein binding from a high-throughput interaction screen. 'Protein binding' is uninformative and no more specific molecular function is supported by this screen alone. Removal does not mean the interaction is false. |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | REMOVE | Summary: Protein binding with UniProtKB:P00540 from high-throughput screens. Reason: Generic protein binding from a high-throughput interaction screen. 'Protein binding' is uninformative and no more specific molecular function is supported by this screen alone. Removal does not mean the interaction is false. |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | REMOVE | Summary: Protein binding with UniProtKB:P09067 from high-throughput screens. Reason: Generic protein binding from a high-throughput interaction screen. 'Protein binding' is uninformative and no more specific molecular function is supported by this screen alone. Removal does not mean the interaction is false. |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | REMOVE | Summary: Protein binding with UniProtKB:P19878 from high-throughput screens. Reason: Generic protein binding from a high-throughput interaction screen. 'Protein binding' is uninformative and no more specific molecular function is supported by this screen alone. Removal does not mean the interaction is false. |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | REMOVE | Summary: Protein binding with UniProtKB:P41227 from high-throughput screens. Reason: Generic protein binding from a high-throughput interaction screen. 'Protein binding' is uninformative and no more specific molecular function is supported by this screen alone. Removal does not mean the interaction is false. |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | REMOVE | Summary: Protein binding with UniProtKB:Q14D33 from high-throughput screens. Reason: Generic protein binding from a high-throughput interaction screen. 'Protein binding' is uninformative and no more specific molecular function is supported by this screen alone. Removal does not mean the interaction is false. |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | REMOVE | Summary: Protein binding with UniProtKB:Q63ZY3 from high-throughput screens. Reason: Generic protein binding from a high-throughput interaction screen. 'Protein binding' is uninformative and no more specific molecular function is supported by this screen alone. Removal does not mean the interaction is false. |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | REMOVE | Summary: Protein binding with UniProtKB:Q86VE0 from high-throughput screens. Reason: Generic protein binding from a high-throughput interaction screen. 'Protein binding' is uninformative and no more specific molecular function is supported by this screen alone. Removal does not mean the interaction is false. |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | REMOVE | Summary: Protein binding with UniProtKB:Q9BSU3 from high-throughput screens. Reason: Generic protein binding from a high-throughput interaction screen. 'Protein binding' is uninformative and no more specific molecular function is supported by this screen alone. Removal does not mean the interaction is false. |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | REMOVE | Summary: Protein binding with UniProtKB:Q9H6X5-2 from high-throughput screens. Reason: Generic protein binding from a high-throughput interaction screen. 'Protein binding' is uninformative and no more specific molecular function is supported by this screen alone. Removal does not mean the interaction is false. |
| GO:0005515 protein binding | IPI PMID:33961781 Dual proteome-scale networks reveal cell-specific remodeling... | MODIFY | Summary: Interaction with KIF3A/KIF3B motor subunits. Reason: Interaction of KIFAP3 with the kinesin-2 motor subunits KIF3A/KIF3B. For KAP3 this interaction is its defining molecular function: it binds the KIF3A/KIF3B tail domains to form the heterotrimeric motor. 'Protein binding' is uninformative; the more specific term kinesin binding (GO:0019894) is appropriate and already supported by IPI for the same pairs. Proposed replacements: kinesin binding Supporting Evidence: file:human/KIFAP3/KIFAP3-uniprot.txt Binds to the tail domain of the KIF3A/KIF3B heterodimer to form a heterotrimeric KIF3 complex and may regulate the membrane binding of this complex PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. |
| GO:0005515 protein binding | IPI PMID:33961781 Dual proteome-scale networks reveal cell-specific remodeling... | MODIFY | Summary: Interaction with KIF3A/KIF3B motor subunits. Reason: Interaction of KIFAP3 with the kinesin-2 motor subunits KIF3A/KIF3B. For KAP3 this interaction is its defining molecular function: it binds the KIF3A/KIF3B tail domains to form the heterotrimeric motor. 'Protein binding' is uninformative; the more specific term kinesin binding (GO:0019894) is appropriate and already supported by IPI for the same pairs. Proposed replacements: kinesin binding Supporting Evidence: file:human/KIFAP3/KIFAP3-uniprot.txt Binds to the tail domain of the KIF3A/KIF3B heterodimer to form a heterotrimeric KIF3 complex and may regulate the membrane binding of this complex PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. |
| GO:0005515 protein binding | IPI PMID:35271311 OpenCell: Endogenous tagging for the cartography of human ce... | MODIFY | Summary: Interaction with KIF3A/KIF3B motor subunits. Reason: Interaction of KIFAP3 with the kinesin-2 motor subunits KIF3A/KIF3B. For KAP3 this interaction is its defining molecular function: it binds the KIF3A/KIF3B tail domains to form the heterotrimeric motor. 'Protein binding' is uninformative; the more specific term kinesin binding (GO:0019894) is appropriate and already supported by IPI for the same pairs. Proposed replacements: kinesin binding Supporting Evidence: file:human/KIFAP3/KIFAP3-uniprot.txt Binds to the tail domain of the KIF3A/KIF3B heterodimer to form a heterotrimeric KIF3 complex and may regulate the membrane binding of this complex PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. |
| GO:0005515 protein binding | IPI PMID:35271311 OpenCell: Endogenous tagging for the cartography of human ce... | MODIFY | Summary: Interaction with KIF3A/KIF3B motor subunits. Reason: Interaction of KIFAP3 with the kinesin-2 motor subunits KIF3A/KIF3B. For KAP3 this interaction is its defining molecular function: it binds the KIF3A/KIF3B tail domains to form the heterotrimeric motor. 'Protein binding' is uninformative; the more specific term kinesin binding (GO:0019894) is appropriate and already supported by IPI for the same pairs. Proposed replacements: kinesin binding Supporting Evidence: file:human/KIFAP3/KIFAP3-uniprot.txt Binds to the tail domain of the KIF3A/KIF3B heterodimer to form a heterotrimeric KIF3 complex and may regulate the membrane binding of this complex PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. |
| GO:0005515 protein binding | IPI PMID:40205054 Multimodal cell maps as a foundation for structural and func... | MODIFY | Summary: Interaction with KIF3A/KIF3B motor subunits. Reason: Interaction of KIFAP3 with the kinesin-2 motor subunits KIF3A/KIF3B. For KAP3 this interaction is its defining molecular function: it binds the KIF3A/KIF3B tail domains to form the heterotrimeric motor. 'Protein binding' is uninformative; the more specific term kinesin binding (GO:0019894) is appropriate and already supported by IPI for the same pairs. Proposed replacements: kinesin binding Supporting Evidence: file:human/KIFAP3/KIFAP3-uniprot.txt Binds to the tail domain of the KIF3A/KIF3B heterodimer to form a heterotrimeric KIF3 complex and may regulate the membrane binding of this complex PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. |
| GO:0005515 protein binding | IPI PMID:40205054 Multimodal cell maps as a foundation for structural and func... | MODIFY | Summary: Interaction with KIF3A/KIF3B motor subunits. Reason: Interaction of KIFAP3 with the kinesin-2 motor subunits KIF3A/KIF3B. For KAP3 this interaction is its defining molecular function: it binds the KIF3A/KIF3B tail domains to form the heterotrimeric motor. 'Protein binding' is uninformative; the more specific term kinesin binding (GO:0019894) is appropriate and already supported by IPI for the same pairs. Proposed replacements: kinesin binding Supporting Evidence: file:human/KIFAP3/KIFAP3-uniprot.txt Binds to the tail domain of the KIF3A/KIF3B heterodimer to form a heterotrimeric KIF3 complex and may regulate the membrane binding of this complex PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. |
| GO:0005515 protein binding | IPI PMID:9506951 Complex formation of SMAP/KAP3, a KIF3A/B ATPase motor-assoc... | REMOVE | Summary: Interaction with SMC3 (9506951). Reason: SMAP/KAP3 was reported to bind a chromosome-associated SMC protein and proposed to link chromosomes to KIF3A/B. 'Protein binding' is uninformative and no specific function is established. Removal does not mean the interaction is false. Supporting Evidence: PMID:9506951 The results suggest that SMAP/KAP3 serves as a linker between HCAP and KIF3A/B in the nucleus, and that SMAP/KAP3 plays a role in the interaction of chromosomes with an ATPase motor protein. |
| GO:0005783 endoplasmic reticulum | IEA GO_REF:0000107 | KEEP AS NON CORE | Summary: endoplasmic reticulum localization. Reason: SMAP/KAP3 is concentrated in the endoplasmic reticulum area in fractionation/staining; consistent with its role on membranous organelle cargo, but not a primary site of function. ORGANELLES check (2026-11-05): the Ensembl projection rests on one mouse annotation, MGI IDA to Kifap3 (P70188) from PMID:19384852, a pre-embedding immuno-EM study of endogenous KAP3 in photoreceptors that places KAP3 along ER and Golgi membranes of the inner segment. That is a real, endogenous pool, so the row stays KEEP_AS_NON_CORE. KAP3 is the soluble cargo-binding subunit of kinesin-II with no signal peptide or TM segment, so the pool is on the cytosolic face of the membranes (a recruited motor-adaptor pool) and stays at the root; no ER-membrane row is added. Supporting Evidence: PMID:8900189 SMAP was ubiquitously expressed and highly concentrated at the endoplasmic reticulum area PMID:19384852 Furthermore, KAP3 was localized along ER and Golgi membranes as well as tubulo-vesicular elements within the IS |
| GO:0005783 endoplasmic reticulum | TAS PMID:8900189 SMAP, an Smg GDS-associating protein having arm repeats and ... | KEEP AS NON CORE | Summary: endoplasmic reticulum localization. Reason: SMAP/KAP3 is concentrated in the endoplasmic reticulum area in fractionation/staining; consistent with its role on membranous organelle cargo, but not a primary site of function. ORGANELLES check (2026-11-05): the source (PMID:8900189, abstract only) reports SMAP concentrated at the ER area, without an ER marker named in the abstract; endogenous mouse KAP3 is also seen along ER and Golgi membranes by immuno-EM (PMID:19384852). As a soluble kinesin-II subunit with no signal peptide or TM segment, its ER pool is a recruited cytosolic-face pool, so it stays at the root and is peripheral to the motor-adaptor function. Supporting Evidence: PMID:8900189 SMAP was ubiquitously expressed and highly concentrated at the endoplasmic reticulum area PMID:19384852 Furthermore, KAP3 was localized along ER and Golgi membranes as well as tubulo-vesicular elements within the IS |
| GO:0005794 Golgi apparatus | IEA GO_REF:0000107 | KEEP AS NON CORE | Summary: Golgi apparatus localization. Reason: SMAP/KAP3 is concentrated in the endoplasmic reticulum area in fractionation/staining; consistent with its role on membranous organelle cargo, but not a primary site of function. Supporting Evidence: PMID:8900189 SMAP was ubiquitously expressed and highly concentrated at the endoplasmic reticulum area |
| GO:0005813 centrosome | IDA PMID:16298999 Role of the kinesin-2 family protein, KIF3, during mitosis. | ACCEPT | Summary: Centrosome localization (IDA). Reason: Kinesin-2 including KAP3 localizes to centrosomes; consistent with HPA basal body staining. Supporting Evidence: PMID:16298999 the kinesin-2 complex is localized with components of the mitotic apparatus such as spindle microtubules and centrosomes PMID:41005307 We employed antibody-based spatial proteomics to expand the Human Protein Atlas to primary cilia. |
| GO:0005829 cytosol | TAS Reactome:R-HSA-2213248 | ACCEPT | Summary: cytosol localization. Reason: KAP3 is part of a cytoplasmic microtubule motor; HPA detects KIFAP3 on microtubules. Supporting Evidence: PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. |
| GO:0005829 cytosol | TAS Reactome:R-HSA-6811423 | ACCEPT | Summary: cytosol localization. Reason: KAP3 is part of a cytoplasmic microtubule motor; HPA detects KIFAP3 on microtubules. Supporting Evidence: PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. |
| GO:0005829 cytosol | TAS Reactome:R-HSA-6811426 | ACCEPT | Summary: cytosol localization. Reason: KAP3 is part of a cytoplasmic microtubule motor; HPA detects KIFAP3 on microtubules. Supporting Evidence: PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. |
| GO:0005829 cytosol | TAS Reactome:R-HSA-983259 | ACCEPT | Summary: cytosol localization. Reason: KAP3 is part of a cytoplasmic microtubule motor; HPA detects KIFAP3 on microtubules. Supporting Evidence: PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. |
| GO:0005829 cytosol | TAS Reactome:R-HSA-983266 | ACCEPT | Summary: cytosol localization. Reason: KAP3 is part of a cytoplasmic microtubule motor; HPA detects KIFAP3 on microtubules. Supporting Evidence: PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. |
| GO:0005871 kinesin complex | IEA GO_REF:0000002 | ACCEPT | Summary: kinesin complex. Reason: KIFAP3 is the non-motor subunit of heterotrimeric kinesin-2. Supporting Evidence: PMID:24338362 The kinesin-2 motor is a heterotrimeric complex composed of KIF3A, KIF3B motor subunits and KAP3, the non-motor subunit, which binds the cargo. file:human/KIFAP3/KIFAP3-uniprot.txt Heterotrimer of KIFAP3, KIF3A and KIF3B. |
| GO:0005876 spindle microtubule | IDA PMID:16298999 Role of the kinesin-2 family protein, KIF3, during mitosis. | KEEP AS NON CORE | Summary: spindle microtubule (IDA). Reason: Kinesin-2 is reported with spindle microtubules and KAP3 with chromosomes in mitosis; a secondary, less established role. Supporting Evidence: PMID:16298999 the kinesin-2 complex is localized with components of the mitotic apparatus such as spindle microtubules and centrosomes PMID:9506951 The results suggest that SMAP/KAP3 serves as a linker between HCAP and KIF3A/B in the nucleus, and that SMAP/KAP3 plays a role in the interaction of chromosomes with an ATPase motor protein. |
| GO:0005929 cilium | TAS Reactome:R-HSA-5624949 | ACCEPT | Summary: cilium localization. Reason: As a subunit of the anterograde IFT motor, KAP3 is found at the ciliary base, along the axoneme and at the tip; HPA detects KIFAP3 at the basal body (Approved). Supporting Evidence: PMID:32386558 Molecular motor activity is driven by a heterotrimeric complex comprised of KIF3A and KIF3B or KIF3C plus one non-motor subunit, KIFAP3. PMID:41005307 We employed antibody-based spatial proteomics to expand the Human Protein Atlas to primary cilia. |
| GO:0005929 cilium | TAS Reactome:R-HSA-5625416 | ACCEPT | Summary: cilium localization. Reason: As a subunit of the anterograde IFT motor, KAP3 is found at the ciliary base, along the axoneme and at the tip; HPA detects KIFAP3 at the basal body (Approved). Supporting Evidence: PMID:32386558 Molecular motor activity is driven by a heterotrimeric complex comprised of KIF3A and KIF3B or KIF3C plus one non-motor subunit, KIFAP3. PMID:41005307 We employed antibody-based spatial proteomics to expand the Human Protein Atlas to primary cilia. |
| GO:0005929 cilium | TAS Reactome:R-HSA-5625424 | ACCEPT | Summary: cilium localization. Reason: As a subunit of the anterograde IFT motor, KAP3 is found at the ciliary base, along the axoneme and at the tip; HPA detects KIFAP3 at the basal body (Approved). Supporting Evidence: PMID:32386558 Molecular motor activity is driven by a heterotrimeric complex comprised of KIF3A and KIF3B or KIF3C plus one non-motor subunit, KIFAP3. PMID:41005307 We employed antibody-based spatial proteomics to expand the Human Protein Atlas to primary cilia. |
| GO:0005929 cilium | TAS Reactome:R-HSA-5625426 | ACCEPT | Summary: cilium localization. Reason: As a subunit of the anterograde IFT motor, KAP3 is found at the ciliary base, along the axoneme and at the tip; HPA detects KIFAP3 at the basal body (Approved). Supporting Evidence: PMID:32386558 Molecular motor activity is driven by a heterotrimeric complex comprised of KIF3A and KIF3B or KIF3C plus one non-motor subunit, KIFAP3. PMID:41005307 We employed antibody-based spatial proteomics to expand the Human Protein Atlas to primary cilia. |
| GO:0005930 axoneme | IBA GO_REF:0000033 | ACCEPT | Summary: axoneme localization. Reason: As a subunit of the anterograde IFT motor, KAP3 is found at the ciliary base, along the axoneme and at the tip; HPA detects KIFAP3 at the basal body (Approved). Electronic annotation consistent with experimental and phylogenetic evidence. Supporting Evidence: PMID:32386558 Molecular motor activity is driven by a heterotrimeric complex comprised of KIF3A and KIF3B or KIF3C plus one non-motor subunit, KIFAP3. PMID:41005307 We employed antibody-based spatial proteomics to expand the Human Protein Atlas to primary cilia. |
| GO:0005930 axoneme | IEA GO_REF:0000107 | ACCEPT | Summary: axoneme localization. Reason: As a subunit of the anterograde IFT motor, KAP3 is found at the ciliary base, along the axoneme and at the tip; HPA detects KIFAP3 at the basal body (Approved). Electronic annotation consistent with experimental and phylogenetic evidence. Supporting Evidence: PMID:32386558 Molecular motor activity is driven by a heterotrimeric complex comprised of KIF3A and KIF3B or KIF3C plus one non-motor subunit, KIFAP3. PMID:41005307 We employed antibody-based spatial proteomics to expand the Human Protein Atlas to primary cilia. |
| GO:0007017 microtubule-based process | IEA GO_REF:0000107 | ACCEPT | Summary: microtubule-based process. Reason: As the cargo-linking subunit of kinesin-2, KAP3 participates in plus-end-directed microtubule transport of organelles (it does not itself generate force). Supporting Evidence: PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. PMID:8900189 SpKAP115 is an accessory subunit of sea urchin kinesin II, an ATPase motor that transports vesicles along microtubules. |
| GO:0007017 microtubule-based process | ISS GO_REF:0000024 | ACCEPT | Summary: microtubule-based process. Reason: As the cargo-linking subunit of kinesin-2, KAP3 participates in plus-end-directed microtubule transport of organelles (it does not itself generate force). Supporting Evidence: PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. PMID:8900189 SpKAP115 is an accessory subunit of sea urchin kinesin II, an ATPase motor that transports vesicles along microtubules. |
| GO:0007018 microtubule-based movement | IBA GO_REF:0000033 | ACCEPT | Summary: microtubule-based movement. Reason: As the cargo-linking subunit of kinesin-2, KAP3 participates in plus-end-directed microtubule transport of organelles (it does not itself generate force). Supporting Evidence: PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. PMID:8900189 SpKAP115 is an accessory subunit of sea urchin kinesin II, an ATPase motor that transports vesicles along microtubules. |
| GO:0007165 signal transduction | TAS PMID:8900189 SMAP, an Smg GDS-associating protein having arm repeats and ... | MARK AS OVER ANNOTATED | Summary: Signal transduction (TAS). Reason: Based on SMAP binding SmgGDS and Src phosphorylation; the authors only suggest an adaptor linkage to signalling. KAP3 is not itself a signal transducer. Supporting Evidence: PMID:8900189 These results suggest that SMAP serves as an adaptor for both Smg GDS and kinesin II or its related protein and links them with both the Smg GDS-regulated small G protein and Src tyrosine kinase signalings. |
| GO:0010970 transport along microtubule | IEA GO_REF:0000117 | ACCEPT | Summary: transport along microtubule. Reason: As the cargo-linking subunit of kinesin-2, KAP3 participates in plus-end-directed microtubule transport of organelles (it does not itself generate force). Supporting Evidence: PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. PMID:8900189 SpKAP115 is an accessory subunit of sea urchin kinesin II, an ATPase motor that transports vesicles along microtubules. |
| GO:0015630 microtubule cytoskeleton | IDA PMID:16298999 Role of the kinesin-2 family protein, KIF3, during mitosis. | ACCEPT | Summary: microtubule cytoskeleton localization. Reason: KAP3 is part of a cytoplasmic microtubule motor; HPA detects KIFAP3 on microtubules. Supporting Evidence: PMID:16298999 the kinesin-2 complex is localized with components of the mitotic apparatus such as spindle microtubules and centrosomes |
| GO:0015630 microtubule cytoskeleton | IEA GO_REF:0000107 | ACCEPT | Summary: microtubule cytoskeleton localization. Reason: KAP3 is part of a cytoplasmic microtubule motor; HPA detects KIFAP3 on microtubules. Supporting Evidence: PMID:16298999 the kinesin-2 complex is localized with components of the mitotic apparatus such as spindle microtubules and centrosomes |
| GO:0016939 kinesin II complex | IBA GO_REF:0000033 | ACCEPT | Summary: kinesin II complex. Reason: KIFAP3 is the non-motor subunit of heterotrimeric kinesin-2. Supporting Evidence: PMID:24338362 The kinesin-2 motor is a heterotrimeric complex composed of KIF3A, KIF3B motor subunits and KAP3, the non-motor subunit, which binds the cargo. file:human/KIFAP3/KIFAP3-uniprot.txt Heterotrimer of KIFAP3, KIF3A and KIF3B. |
| GO:0016939 kinesin II complex | IDA PMID:16298999 Role of the kinesin-2 family protein, KIF3, during mitosis. | ACCEPT | Summary: kinesin II complex. Reason: KIFAP3 is the non-motor subunit of heterotrimeric kinesin-2. Supporting Evidence: PMID:24338362 The kinesin-2 motor is a heterotrimeric complex composed of KIF3A, KIF3B motor subunits and KAP3, the non-motor subunit, which binds the cargo. file:human/KIFAP3/KIFAP3-uniprot.txt Heterotrimer of KIFAP3, KIF3A and KIF3B. |
| GO:0016939 kinesin II complex | IEA GO_REF:0000120 | ACCEPT | Summary: kinesin II complex. Reason: KIFAP3 is the non-motor subunit of heterotrimeric kinesin-2. Supporting Evidence: PMID:24338362 The kinesin-2 motor is a heterotrimeric complex composed of KIF3A, KIF3B motor subunits and KAP3, the non-motor subunit, which binds the cargo. file:human/KIFAP3/KIFAP3-uniprot.txt Heterotrimer of KIFAP3, KIF3A and KIF3B. |
| GO:0016939 kinesin II complex | ISS GO_REF:0000024 | ACCEPT | Summary: kinesin II complex. Reason: KIFAP3 is the non-motor subunit of heterotrimeric kinesin-2. Supporting Evidence: PMID:24338362 The kinesin-2 motor is a heterotrimeric complex composed of KIF3A, KIF3B motor subunits and KAP3, the non-motor subunit, which binds the cargo. file:human/KIFAP3/KIFAP3-uniprot.txt Heterotrimer of KIFAP3, KIF3A and KIF3B. |
| GO:0019894 kinesin binding | IEA GO_REF:0000002 | ACCEPT | Summary: Kinesin binding. Reason: KAP3 binds the tail domains of KIF3A/KIF3B to form heterotrimeric kinesin-2; its defining molecular function. Supporting Evidence: file:human/KIFAP3/KIFAP3-uniprot.txt Binds to the tail domain of the KIF3A/KIF3B heterodimer to form a heterotrimeric KIF3 complex and may regulate the membrane binding of this complex PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. PMID:7559760 Immunoprecipitation assay of the brain revealed that KIF3B forms a complex with KIF3A and three other high molecular weight (approximately 100 kD)-associated polypeptides, called the kinesin superfamily-associated protein 3 (KAP3). |
| GO:0019894 kinesin binding | IPI PMID:16298999 Role of the kinesin-2 family protein, KIF3, during mitosis. | ACCEPT | Summary: Kinesin binding. Reason: KAP3 binds the tail domains of KIF3A/KIF3B to form heterotrimeric kinesin-2; its defining molecular function. Supporting Evidence: file:human/KIFAP3/KIFAP3-uniprot.txt Binds to the tail domain of the KIF3A/KIF3B heterodimer to form a heterotrimeric KIF3 complex and may regulate the membrane binding of this complex PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. PMID:7559760 Immunoprecipitation assay of the brain revealed that KIF3B forms a complex with KIF3A and three other high molecular weight (approximately 100 kD)-associated polypeptides, called the kinesin superfamily-associated protein 3 (KAP3). |
| GO:0019894 kinesin binding | IPI PMID:16298999 Role of the kinesin-2 family protein, KIF3, during mitosis. | ACCEPT | Summary: Kinesin binding. Reason: KAP3 binds the tail domains of KIF3A/KIF3B to form heterotrimeric kinesin-2; its defining molecular function. Supporting Evidence: file:human/KIFAP3/KIFAP3-uniprot.txt Binds to the tail domain of the KIF3A/KIF3B heterodimer to form a heterotrimeric KIF3 complex and may regulate the membrane binding of this complex PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. PMID:7559760 Immunoprecipitation assay of the brain revealed that KIF3B forms a complex with KIF3A and three other high molecular weight (approximately 100 kD)-associated polypeptides, called the kinesin superfamily-associated protein 3 (KAP3). |
| GO:0019903 protein phosphatase binding | IPI PMID:24338362 POPX2 phosphatase regulates the KIF3 kinesin motor complex. | KEEP AS NON CORE | Summary: Protein phosphatase binding (POPX2/POPX1). Reason: POPX2 binds KAP3 and regulates kinesin-2 cargo trafficking via KIF3A dephosphorylation; regulatory interaction. Supporting Evidence: PMID:24338362 we have identified POPX2, a serine-threonine phosphatase, as an interacting partner of the KAP3 subunit of the kinesin-2 motor PMID:24338362 POPX2 affects trafficking by determining the phosphorylation status of KIF3A at serine 690. This is consistent with the observation that the KIF3A-S690A mutant is defective in cargo trafficking. |
| GO:0019903 protein phosphatase binding | IPI PMID:24338362 POPX2 phosphatase regulates the KIF3 kinesin motor complex. | KEEP AS NON CORE | Summary: Protein phosphatase binding (POPX2/POPX1). Reason: POPX2 binds KAP3 and regulates kinesin-2 cargo trafficking via KIF3A dephosphorylation; regulatory interaction. Supporting Evidence: PMID:24338362 we have identified POPX2, a serine-threonine phosphatase, as an interacting partner of the KAP3 subunit of the kinesin-2 motor PMID:24338362 POPX2 affects trafficking by determining the phosphorylation status of KIF3A at serine 690. This is consistent with the observation that the KIF3A-S690A mutant is defective in cargo trafficking. |
| GO:0032391 photoreceptor connecting cilium | IEA GO_REF:0000107 | KEEP AS NON CORE | Summary: photoreceptor connecting cilium (from mouse). Reason: Photoreceptor/periciliary localization transferred from mouse Kifap3, a cell-type-specific instance of its ciliary localization. Supporting Evidence: PMID:32386558 Molecular motor activity is driven by a heterotrimeric complex comprised of KIF3A and KIF3B or KIF3C plus one non-motor subunit, KIFAP3. |
| GO:0032839 dendrite cytoplasm | IEA GO_REF:0000108 | KEEP AS NON CORE | Summary: dendrite cytoplasm (from mouse). Reason: Neuronal dendritic/synaptic transport context of kinesin-2 transferred from mouse; non-ciliary, non-core. Supporting Evidence: PMID:9506951 SMAP is a human counterpart of mouse KAP3 (kinesin superfamily-associated protein) that is associated with mouse KIF3A/B (a kinesin superfamily protein), which functions as a microtubule-based ATPase motor for organelle transport. |
| GO:0035869 ciliary transition zone | IBA GO_REF:0000033 | ACCEPT | Summary: ciliary transition zone localization. Reason: As a subunit of the anterograde IFT motor, KAP3 is found at the ciliary base, along the axoneme and at the tip; HPA detects KIFAP3 at the basal body (Approved). Electronic annotation consistent with experimental and phylogenetic evidence. Supporting Evidence: PMID:32386558 Molecular motor activity is driven by a heterotrimeric complex comprised of KIF3A and KIF3B or KIF3C plus one non-motor subunit, KIFAP3. PMID:41005307 We employed antibody-based spatial proteomics to expand the Human Protein Atlas to primary cilia. |
| GO:0036064 ciliary basal body | IEA GO_REF:0000107 | ACCEPT | Summary: ciliary basal body localization. Reason: As a subunit of the anterograde IFT motor, KAP3 is found at the ciliary base, along the axoneme and at the tip; HPA detects KIFAP3 at the basal body (Approved). Electronic annotation consistent with experimental and phylogenetic evidence. Supporting Evidence: PMID:32386558 Molecular motor activity is driven by a heterotrimeric complex comprised of KIF3A and KIF3B or KIF3C plus one non-motor subunit, KIFAP3. PMID:41005307 We employed antibody-based spatial proteomics to expand the Human Protein Atlas to primary cilia. |
| GO:0044782 cilium organization | IBA GO_REF:0000033 | ACCEPT | Summary: Cilium organization (IBA). Reason: KAP3 is a subunit of the kinesin-2 anterograde IFT motor required for cilium assembly and maintenance. Supporting Evidence: PMID:32386558 Kinesin-2 enables ciliary assembly and maintenance as an anterograde intraflagellar transport (IFT) motor. PMID:32386558 Molecular motor activity is driven by a heterotrimeric complex comprised of KIF3A and KIF3B or KIF3C plus one non-motor subunit, KIFAP3. |
| GO:0065003 protein-containing complex assembly | TAS PMID:8900189 SMAP, an Smg GDS-associating protein having arm repeats and ... | MARK AS OVER ANNOTATED | Summary: Protein-containing complex assembly (TAS). Reason: KAP3 is itself a complex subunit; its binding to KIF3A/B is captured by kinesin binding and kinesin II complex. No evidence that it assembles other complexes. Supporting Evidence: PMID:8900189 These results suggest that SMAP serves as an adaptor for both Smg GDS and kinesin II or its related protein and links them with both the Smg GDS-regulated small G protein and Src tyrosine kinase signalings. |
| GO:0072383 plus-end-directed vesicle transport along microtubule | TAS PMID:16298999 Role of the kinesin-2 family protein, KIF3, during mitosis. | ACCEPT | Summary: plus-end-directed vesicle transport along microtubule. Reason: As the cargo-linking subunit of kinesin-2, KAP3 participates in plus-end-directed microtubule transport of organelles (it does not itself generate force). Supporting Evidence: PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. PMID:8900189 SpKAP115 is an accessory subunit of sea urchin kinesin II, an ATPase motor that transports vesicles along microtubules. |
| GO:0097542 ciliary tip | TAS Reactome:R-HSA-5624952 | ACCEPT | Summary: ciliary tip localization. Reason: As a subunit of the anterograde IFT motor, KAP3 is found at the ciliary base, along the axoneme and at the tip; HPA detects KIFAP3 at the basal body (Approved). Supporting Evidence: PMID:32386558 Molecular motor activity is driven by a heterotrimeric complex comprised of KIF3A and KIF3B or KIF3C plus one non-motor subunit, KIFAP3. PMID:41005307 We employed antibody-based spatial proteomics to expand the Human Protein Atlas to primary cilia. |
| GO:0097542 ciliary tip | TAS Reactome:R-HSA-5625416 | ACCEPT | Summary: ciliary tip localization. Reason: As a subunit of the anterograde IFT motor, KAP3 is found at the ciliary base, along the axoneme and at the tip; HPA detects KIFAP3 at the basal body (Approved). Supporting Evidence: PMID:32386558 Molecular motor activity is driven by a heterotrimeric complex comprised of KIF3A and KIF3B or KIF3C plus one non-motor subunit, KIFAP3. PMID:41005307 We employed antibody-based spatial proteomics to expand the Human Protein Atlas to primary cilia. |
| GO:0097542 ciliary tip | TAS Reactome:R-HSA-5625421 | ACCEPT | Summary: ciliary tip localization. Reason: As a subunit of the anterograde IFT motor, KAP3 is found at the ciliary base, along the axoneme and at the tip; HPA detects KIFAP3 at the basal body (Approved). Supporting Evidence: PMID:32386558 Molecular motor activity is driven by a heterotrimeric complex comprised of KIF3A and KIF3B or KIF3C plus one non-motor subunit, KIFAP3. PMID:41005307 We employed antibody-based spatial proteomics to expand the Human Protein Atlas to primary cilia. |
| GO:0097542 ciliary tip | TAS Reactome:R-HSA-5625426 | ACCEPT | Summary: ciliary tip localization. Reason: As a subunit of the anterograde IFT motor, KAP3 is found at the ciliary base, along the axoneme and at the tip; HPA detects KIFAP3 at the basal body (Approved). Supporting Evidence: PMID:32386558 Molecular motor activity is driven by a heterotrimeric complex comprised of KIF3A and KIF3B or KIF3C plus one non-motor subunit, KIFAP3. PMID:41005307 We employed antibody-based spatial proteomics to expand the Human Protein Atlas to primary cilia. |
| GO:0098794 postsynapse | IEA GO_REF:0000107 | KEEP AS NON CORE | Summary: postsynapse (from mouse). Reason: Neuronal dendritic/synaptic transport context of kinesin-2 transferred from mouse; non-ciliary, non-core. Supporting Evidence: PMID:9506951 SMAP is a human counterpart of mouse KAP3 (kinesin superfamily-associated protein) that is associated with mouse KIF3A/B (a kinesin superfamily protein), which functions as a microtubule-based ATPase motor for organelle transport. |
| GO:0098971 anterograde dendritic transport of neurotransmitter receptor complex | IEA GO_REF:0000107 | KEEP AS NON CORE | Summary: anterograde dendritic transport of neurotransmitter receptor complex (from mouse). Reason: Neuronal dendritic/synaptic transport context of kinesin-2 transferred from mouse; non-ciliary, non-core. Supporting Evidence: PMID:9506951 SMAP is a human counterpart of mouse KAP3 (kinesin superfamily-associated protein) that is associated with mouse KIF3A/B (a kinesin superfamily protein), which functions as a microtubule-based ATPase motor for organelle transport. |
| GO:0098978 glutamatergic synapse | IEA GO_REF:0000107 | KEEP AS NON CORE | Summary: glutamatergic synapse (from mouse). Reason: Neuronal dendritic/synaptic transport context of kinesin-2 transferred from mouse; non-ciliary, non-core. Supporting Evidence: PMID:9506951 SMAP is a human counterpart of mouse KAP3 (kinesin superfamily-associated protein) that is associated with mouse KIF3A/B (a kinesin superfamily protein), which functions as a microtubule-based ATPase motor for organelle transport. |
| GO:0120170 intraciliary transport particle B binding | IEA GO_REF:0000107 | ACCEPT | Summary: Intraciliary transport particle B binding (from mouse). Reason: Kinesin-2 associates with IFT-B trains; KAP3 links the motor to cargo. Electronic annotation consistent with experimental and phylogenetic evidence. Supporting Evidence: PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. PMID:32386558 Kinesin-2 enables ciliary assembly and maintenance as an anterograde intraflagellar transport (IFT) motor. |
| GO:1990075 periciliary membrane compartment | IEA GO_REF:0000107 | KEEP AS NON CORE | Summary: periciliary membrane compartment (from mouse). Reason: Photoreceptor/periciliary localization transferred from mouse Kifap3, a cell-type-specific instance of its ciliary localization. Supporting Evidence: PMID:32386558 Molecular motor activity is driven by a heterotrimeric complex comprised of KIF3A and KIF3B or KIF3C plus one non-motor subunit, KIFAP3. |
| GO:0030674 protein-macromolecule adaptor activity | TAS PMID:16298999 Role of the kinesin-2 family protein, KIF3, during mitosis. | NEW | Summary: Proposed: KAP3 is the non-motor subunit of heterotrimeric kinesin-2 that links the KIF3A/KIF3B motor to cargo. Reason: KAP3 has no motor domain; its activity is to bridge the KIF3A/KIF3B tails and cargo-associated proteins. This adaptor activity is more informative than kinesin binding alone and matches how the same activity is asserted for other non-catalytic bridging subunits (e.g. CEP89, CEP97). Both cited papers state the cargo-linking role. Supporting Evidence: PMID:16298999 Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. PMID:24338362 The kinesin-2 motor is a heterotrimeric complex composed of KIF3A, KIF3B motor subunits and KAP3, the non-motor subunit, which binds the cargo. |
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Download this section (compressed HTML)Q: Which IFT or cargo proteins does KAP3 bind directly, and is KAP3 required for kinesin-2 recruitment to IFT trains in human cells or only for non-ciliary cargo?
Suggested experts: Hirokawa N, Scholey JM
Experiment: Generate KIFAP3-KO RPE1 cells and measure ciliogenesis, kinesin-2 ciliary entry and IFT train motility; map KAP3 armadillo-repeat surfaces required for IFT binding by proximity labelling.
Hypothesis: KIFAP3 is required for kinesin-2 engagement with IFT trains.
Type: knockout and live-cell imaging
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