Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0005737 cytoplasm	IBA GO_REF:0000033	ACCEPT	Summary: OSM-3 localizes to the cytoplasm including perinuclear regions and cell bodies of chemosensory neurons, where it exists in an autoinhibited compact conformation before being recruited to IFT particles (PMID:9950681, PMID:17000874). Reason: IBA annotation is phylogenetically well-supported. OSM-3 is present in the cytoplasm of neurons prior to ciliary entry, consistent with its autoinhibition mechanism. Supporting Evidence: PMID:9950681 a punctate localization pattern in the corresponding cell bodies and dendrites PMID:17000874 OSM-3 exists in the cytoplasm in a compact, autoinhibited state and that binding to an IFT particle relieves this autoinhibition file:worm/osm-3/osm-3-deep-research-falcon.md model: Edison Scientific Literature
GO:0005871 kinesin complex	IBA GO_REF:0000033	ACCEPT	Summary: OSM-3 forms a homodimeric kinesin complex that functions as part of the IFT machinery in sensory cilia (PMID:9950681, PMID:17000874). Reason: OSM-3 is a dimeric kinesin motor. The IBA annotation is well-supported by phylogenetic evidence and confirmed by experimental data in C. elegans. Supporting Evidence: PMID:9950681 heterotrimeric CeKinesin-II and dimeric CeOsm-3
GO:0005874 microtubule	IBA GO_REF:0000033	ACCEPT	Summary: OSM-3 is active along microtubules of the ciliary axoneme, moving processively along both doublet microtubules in the middle segment and singlet microtubules in the distal segment (PMID:17000874). Reason: Kinesin motors function on microtubules. OSM-3 translocates along axonemal microtubules during IFT. Supporting Evidence: PMID:17000874 OSM-3 was an active plus end-directed motor in a microtubule gliding assay
GO:0008017 microtubule binding	IBA GO_REF:0000033	ACCEPT	Summary: OSM-3 binds microtubules as part of its motor activity. The motor domain contains conserved microtubule-binding elements characteristic of kinesin motors (PMID:17000874). Reason: Microtubule binding is an essential property of kinesin motors. OSM-3 has a conserved kinesin motor domain with microtubule-binding capability. Supporting Evidence: PMID:17000874 OSM-3 was an active plus end-directed motor in a microtubule gliding assay
GO:0016887 ATP hydrolysis activity	IBA GO_REF:0000033	ACCEPT	Summary: OSM-3 hydrolyzes ATP to power its motor activity. The wild-type protein has a basal ATPase rate of approximately 4 ATP/s/head that increases when autoinhibition is relieved (PMID:17000874). Reason: ATP hydrolysis is essential for kinesin motor function. Direct biochemical measurements confirm OSM-3 ATPase activity. Supporting Evidence: PMID:17000874 low microtubule-stimulated adenosine triphosphatase (ATPase) activity
GO:0043005 neuron projection	IBA GO_REF:0000033	ACCEPT	Summary: OSM-3 is localized to chemosensory neuron projections including dendrites and their ciliated endings (PMID:9950681). Reason: OSM-3 localizes along the dendrites of chemosensory neurons extending to the ciliated endings. Supporting Evidence: PMID:9950681 a punctate localization pattern in the corresponding cell bodies and dendrites
GO:0005929 cilium	IBA GO_REF:0000033	ACCEPT	Summary: OSM-3 localizes to sensory cilia where it functions in IFT. It localizes along the full cilium length including both middle and distal segments (PMID:9950681). Reason: Core cellular localization for OSM-3 function. IBA is well-supported and confirmed by multiple IDA annotations. Supporting Evidence: PMID:9950681 an intense concentration of CeKinesin-II and CeOsm-3 polypeptides in the ciliated endings of these chemosensory neurons
GO:0030030 cell projection organization	IBA GO_REF:0000033	MODIFY	Summary: OSM-3 is required for organizing the distal segment of sensory cilia. Loss of OSM-3 results in cilia lacking distal segments (PMID:17000874). Reason: While technically accurate, this term is too general. OSM-3 has a specific role in cilium organization, not cell projections broadly. Proposed replacements: cilium assembly non-motile cilium assembly
GO:0005815 microtubule organizing center	IBA GO_REF:0000033	MODIFY	Summary: OSM-3 localizes to the ciliary basal body, which serves as the MTOC for the cilium (PMID:27623382). Reason: While basal bodies are MTOCs, the more precise term for OSM-3 localization is ciliary basal body, which is experimentally validated. Proposed replacements: ciliary basal body
GO:0098971 anterograde dendritic transport of neurotransmitter receptor complex	IBA GO_REF:0000033	MARK AS OVER ANNOTATED	Summary: This annotation is based on the mammalian homolog KIF17, which transports neurotransmitter receptors in dendrites. However, OSM-3 in C. elegans functions primarily in ciliary IFT rather than dendritic receptor transport. Reason: This function is established for mammalian KIF17 but not demonstrated for C. elegans OSM-3. OSM-3 is specifically involved in ciliary transport, not general dendritic transport of receptor complexes. Supporting Evidence: PMID:17000874 Autoinhibition regulates the motility of the C.
GO:0008574 plus-end-directed microtubule motor activity	IBA GO_REF:0000033	ACCEPT	Summary: OSM-3 is a plus-end directed motor that drives anterograde transport in cilia. This is confirmed by direct in vitro assays (PMID:17000874). Reason: Core molecular function of OSM-3. IBA is well-supported and confirmed by IDA. Supporting Evidence: PMID:17000874 OSM-3 was an active plus end-directed motor in a microtubule gliding assay
GO:0000166 nucleotide binding	IEA GO_REF:0000043	ACCEPT	Summary: OSM-3 binds nucleotides (ATP/ADP) as part of its motor cycle. UniProt annotates ATP binding based on keywords. Reason: Correct but less informative than ATP binding. The IEA is acceptable as a broader parent annotation.
GO:0003777 microtubule motor activity	IEA GO_REF:0000120	ACCEPT	Summary: OSM-3 is a microtubule motor that moves along microtubules. This is the general molecular function for kinesin motors. Reason: Core molecular function. IEA is appropriate as this is confirmed by experimental data. Supporting Evidence: PMID:17000874 OSM-3 was an active plus end-directed motor in a microtubule gliding assay
GO:0005524 ATP binding	IEA GO_REF:0000120	ACCEPT	Summary: OSM-3 binds ATP at its motor domain for hydrolysis. The UniProt entry notes the ATP binding site at residues 87-94. Reason: Essential molecular function for kinesin motors. Strongly supported by domain analysis and biochemical data. Supporting Evidence: PMID:17000874 microtubule-stimulated adenosine triphosphatase (ATPase) activity
GO:0005856 cytoskeleton	IEA GO_REF:0000120	ACCEPT	Summary: OSM-3 localizes to the cytoskeleton, specifically the microtubule-based axoneme of cilia. Reason: General localization term that is accurate for a microtubule motor.
GO:0005874 microtubule	IEA GO_REF:0000043	ACCEPT	Summary: Duplicate of IBA annotation. OSM-3 is active on microtubules. Reason: Correct annotation, duplicates IBA with different evidence code.
GO:0005929 cilium	IEA GO_REF:0000120	ACCEPT	Summary: Duplicate of IBA annotation. OSM-3 localizes to sensory cilia. Reason: Correct annotation, duplicates IBA with different evidence code.
GO:0005930 axoneme	IEA GO_REF:0000044	ACCEPT	Summary: OSM-3 localizes to and functions along the ciliary axoneme, transporting IFT particles (PMID:17000874). Reason: Correct and specific localization for OSM-3 within the cilium.
GO:0007018 microtubule-based movement	IEA GO_REF:0000120	MODIFY	Summary: OSM-3 drives microtubule-based movement of IFT particles within cilia. Reason: While accurate, a more specific term exists for OSM-3's biological process. Proposed replacements: intraciliary anterograde transport
GO:0008017 microtubule binding	IEA GO_REF:0000002	ACCEPT	Summary: Duplicate of IBA annotation. OSM-3 binds microtubules via its motor domain. Reason: Correct annotation, duplicates IBA with different evidence code (InterPro).
GO:0032839 dendrite cytoplasm	IEA GO_REF:0000108	ACCEPT	Summary: This annotation is inferred from the dendritic transport annotation. OSM-3 does localize to dendrites of sensory neurons (PMID:9950681). Reason: OSM-3 is present in dendrite cytoplasm en route to cilia. Supporting Evidence: PMID:9950681 a punctate localization pattern in the corresponding cell bodies and dendrites
GO:0032991 protein-containing complex	IEA GO_REF:0000117	MODIFY	Summary: OSM-3 forms homodimeric complexes and associates with IFT particles. Reason: Too general. OSM-3 specifically forms kinesin complexes. Proposed replacements: kinesin complex
GO:0030425 dendrite	IDA PMID:9950681 Two heteromeric kinesin complexes in chemosensory neurons an...	ACCEPT	Summary: OSM-3::GFP localizes to dendrites of chemosensory neurons as shown by immunolocalization (PMID:9950681). Reason: Direct experimental evidence from immunolocalization studies. Supporting Evidence: PMID:9950681 a punctate localization pattern in the corresponding cell bodies and dendrites
GO:1902856 negative regulation of non-motile cilium assembly	IGI PMID:17420466 Mutation of the MAP kinase DYF-5 affects docking and undocki...	UNDECIDED	Summary: In dyf-5 mutants, OSM-3 accumulates and moves at reduced speed, and cilia become elongated. This suggests complex regulatory interactions affecting cilium length (PMID:17420466). Reason: The relationship between OSM-3 and negative regulation of cilium assembly is indirect and context-dependent (dyf-5 mutant background). OSM-3 primarily promotes cilium assembly; negative regulation may be a secondary effect. Supporting Evidence: PMID:17420466 Mutation of the MAP kinase DYF-5 affects docking and undocking of kinesin-2 motors and reduces their speed in the cilia of Caenorhabditis elegans.
GO:1902857 positive regulation of non-motile cilium assembly	IGI PMID:17420466 Mutation of the MAP kinase DYF-5 affects docking and undocki...	ACCEPT	Summary: OSM-3 is required for assembly of the distal segment of sensory cilia. Loss of OSM-3 results in truncated cilia (PMID:17420466, PMID:17000874). Reason: OSM-3 is essential for building distal segments and thus positively regulates cilium assembly. Supporting Evidence: PMID:17420466 OSM-3 alone mediates transport in the distal segments PMID:17000874 osm-3-null animals only display a loss of the distal segments of their sensory cilia
GO:0035720 intraciliary anterograde transport	IMP PMID:17420466 Mutation of the MAP kinase DYF-5 affects docking and undocki...	ACCEPT	Summary: OSM-3 drives anterograde IFT in cilia. Mutations affect IFT velocity and docking/undocking of kinesin motors (PMID:17420466). Reason: Core biological function of OSM-3. IMP evidence from dyf-5 mutant studies. Supporting Evidence: PMID:17420466 anterograde intraflagellar transport (IFT) is mediated by two kinesin-2 complexes, kinesin II and OSM-3 kinesin
GO:0035720 intraciliary anterograde transport	IGI PMID:17420466 Mutation of the MAP kinase DYF-5 affects docking and undocki...	ACCEPT	Summary: Genetic interaction with dyf-5 demonstrates OSM-3's role in anterograde IFT. Reason: Supports the IMP annotation with genetic interaction evidence. Supporting Evidence: PMID:17420466 OSM-3 moves at a reduced speed and is not attached to IFT particles
GO:0036064 ciliary basal body	IDA PMID:27623382 A Conserved Role for Girdin in Basal Body Positioning and Ci...	ACCEPT	Summary: OSM-3 localizes to the ciliary basal body as shown by fluorescence microscopy studies examining basal body positioning (PMID:27623382). Reason: Direct experimental localization data from the Girdin study. Supporting Evidence: PMID:27623382 A Conserved Role for Girdin in Basal Body Positioning and Ciliogenesis.
GO:0042073 intraciliary transport	IDA PMID:27623382 A Conserved Role for Girdin in Basal Body Positioning and Ci...	ACCEPT	Summary: OSM-3 functions in intraciliary transport as demonstrated by its localization and movement along the ciliary axoneme. Reason: Core biological function of OSM-3. Supporting Evidence: PMID:27623382 A Conserved Role for Girdin in Basal Body Positioning and Ciliogenesis.
GO:0097730 non-motile cilium	IDA PMID:17420466 Mutation of the MAP kinase DYF-5 affects docking and undocki...	ACCEPT	Summary: OSM-3 localizes to non-motile sensory cilia in C. elegans chemosensory neurons (PMID:17420466). Reason: C. elegans sensory cilia are non-motile (primary) cilia. OSM-3 localizes to these structures. Supporting Evidence: PMID:17420466 In the cilia of the nematode Caenorhabditis elegans
GO:1902857 positive regulation of non-motile cilium assembly	IMP PMID:17420466 Mutation of the MAP kinase DYF-5 affects docking and undocki...	ACCEPT	Summary: osm-3 mutants lack distal cilium segments, demonstrating OSM-3's role in promoting cilium assembly (PMID:17420466). Reason: Mutant phenotype analysis supports positive regulation of cilium assembly. Supporting Evidence: PMID:17420466 OSM-3 alone mediates transport in the distal segments
GO:0035720 intraciliary anterograde transport	IDA PMID:17000874 Autoinhibition regulates the motility of the C. elegans intr...	ACCEPT	Summary: Single-molecule analysis demonstrates OSM-3 is a processive motor capable of anterograde transport when autoinhibition is relieved (PMID:17000874). Reason: Direct in vitro demonstration of OSM-3 motor activity consistent with anterograde IFT function. Supporting Evidence: PMID:17000874 OSM-3 is a Kinesin-2 family member from Caenorhabditis elegans that is involved in intraflagellar transport (IFT), a process essential for the construction and maintenance of sensory cilia
GO:0035720 intraciliary anterograde transport	IDA PMID:17000880 Mechanism of transport of IFT particles in C. elegans cilia ...	ACCEPT	Summary: Live imaging shows OSM-3 and kinesin-II cooperatively drive anterograde IFT in the middle segment, while OSM-3 alone transports in the distal segment (PMID:17000880). Reason: Definitive demonstration of OSM-3's role in anterograde IFT through live imaging studies. Supporting Evidence: PMID:17000874 Microscopy studies in living C. elegans have shown that both motors cooperate to move IFT particles along the middle segment of the cilia PMID:17000880 Mechanism of transport of IFT particles in C.
GO:0035720 intraciliary anterograde transport	IMP PMID:26863025 A Screen for Modifiers of Cilia Phenotypes Reveals Novel MKS...	ACCEPT	Summary: osm-3 mutations affect IFT velocity in cilia, with the yhw66 allele reducing anterograde IFT rates (PMID:26863025). Reason: Mutant phenotype analysis confirms OSM-3's role in anterograde IFT. Supporting Evidence: PMID:26863025 In osm-3(yhw66) mutants anterograde intraflagellar transport (IFT) velocity is reduced
GO:1905515 non-motile cilium assembly	IGI PMID:26863025 A Screen for Modifiers of Cilia Phenotypes Reveals Novel MKS...	ACCEPT	Summary: Genetic interactions between osm-3 and nphp-4 affect distal segment formation of non-motile cilia (PMID:26863025). Reason: Genetic interaction data supports OSM-3's role in cilium assembly. Supporting Evidence: PMID:26863025 nphp-4(tm925);osm-3(yhw66) double mutants lack distal segments and are dye-filling (Dyf) and osmotic avoidance (Osm) defective, similar to osm-3(mn357) null mutants
GO:0061066 positive regulation of dauer larval development	IMP PMID:7828815 Multiple chemosensory defects in daf-11 and daf-21 mutants o...	KEEP AS NON CORE	Summary: osm-3 mutations affect chemosensory function and dauer formation. The annotation suggests OSM-3 promotes dauer development (PMID:7828815). Reason: Dauer phenotype is secondary to ciliary defects. OSM-3 mutants have defective sensory cilia which impairs pheromone sensing required for dauer decision. This is not a core function but a downstream consequence. Supporting Evidence: PMID:7828815 Multiple chemosensory defects in daf-11 and daf-21 mutants of Caenorhabditis elegans.
GO:0043053 dauer entry	IGI PMID:1732156 Genetic analysis of chemosensory control of dauer formation ...	KEEP AS NON CORE	Summary: Genetic analysis shows osm-3 affects dauer entry through chemosensory defects (PMID:1732156). Reason: Dauer phenotype is secondary to ciliary defects. OSM-3's role in dauer is indirect through its effects on sensory cilia function. Supporting Evidence: PMID:1732156 Dauer-defective mutations in nine genes cause structurally defective chemosensory cilia, thereby blocking chemosensation
GO:0060271 cilium assembly	IGI PMID:1732156 Genetic analysis of chemosensory control of dauer formation ...	ACCEPT	Summary: Genetic analysis places osm-3 among genes required for proper cilium structure (PMID:1732156). Reason: Core biological function of OSM-3 - required for distal segment assembly. Supporting Evidence: PMID:1732156 Dauer-defective mutations in nine genes cause structurally defective chemosensory cilia
GO:0097730 non-motile cilium	IDA PMID:22342749 Endocytosis genes facilitate protein and membrane transport ...	ACCEPT	Summary: OSM-3 localization in sensory cilia shown by fluorescence microscopy in endocytosis study (PMID:22342749). Reason: Direct localization data supporting ciliary localization. Supporting Evidence: PMID:22342749 Feb 16. Endocytosis genes facilitate protein and membrane transport in C.
GO:0036064 ciliary basal body	IDA PMID:22922713 The BBSome controls IFT assembly and turnaround in cilia.	ACCEPT	Summary: OSM-3 localizes to the basal body region in the context of BBSome-IFT assembly studies (PMID:22922713). Reason: Direct experimental evidence from comprehensive IFT study. Supporting Evidence: PMID:22922713 the BBSome (refs 3, 4), a group of conserved proteins affected in human Bardet-Biedl syndrome(5) (BBS), assembles IFT complexes at the ciliary base, then binds to the anterograde IFT particle in a DYF-2- (an orthologue of human WDR19) and BBS-1-dependent manner, and lastly reaches the ciliary tip to regulate proper IFT recycling
GO:0097730 non-motile cilium	IDA PMID:9950681 Two heteromeric kinesin complexes in chemosensory neurons an...	ACCEPT	Summary: First demonstration of OSM-3 localization in sensory cilia using GFP reporters and immunolocalization (PMID:9950681). Reason: Seminal paper establishing OSM-3 ciliary localization. Supporting Evidence: PMID:9950681 an intense concentration of CeKinesin-II and CeOsm-3 polypeptides in the ciliated endings of these chemosensory neurons
GO:0008574 plus-end-directed microtubule motor activity	IDA PMID:17000874 Autoinhibition regulates the motility of the C. elegans intr...	ACCEPT	Summary: Single-molecule assays directly demonstrate OSM-3 is a plus-end directed motor (PMID:17000874). Reason: Core molecular function with direct biochemical evidence. Supporting Evidence: PMID:17000874 OSM-3 was an active plus end-directed motor in a microtubule gliding assay
GO:0003777 microtubule motor activity	IDA PMID:17000880 Mechanism of transport of IFT particles in C. elegans cilia ...	ACCEPT	Summary: Live imaging demonstrates OSM-3 motor activity in IFT transport at measured velocities (PMID:17000880). Reason: Core molecular function with direct in vivo evidence. Supporting Evidence: PMID:17000880 The assembly and function of cilia on Caenorhabditis elegans neurons depends on the action of two kinesin-2 motors, heterotrimeric kinesin-II and homodimeric OSM-3-kinesin, which cooperate to move the same intraflagellar transport (IFT) particles along microtubule (MT) doublets
GO:0005871 kinesin complex	IDA PMID:17000880 Mechanism of transport of IFT particles in C. elegans cilia ...	ACCEPT	Summary: OSM-3 forms homodimeric kinesin complexes as demonstrated by biochemical and imaging studies (PMID:17000880). Reason: Direct experimental evidence for kinesin complex formation. Supporting Evidence: PMID:17000880 heterotrimeric kinesin-II and homodimeric OSM-3-kinesin, which cooperate to move the same intraflagellar transport (IFT) particles along microtubule (MT) doublets
GO:0043025 neuronal cell body	IDA PMID:9950681 Two heteromeric kinesin complexes in chemosensory neurons an...	ACCEPT	Summary: OSM-3 localizes to the cell bodies of chemosensory neurons as shown by immunolocalization and GFP reporters (PMID:9950681). Reason: Direct localization data in neuronal cell bodies. Supporting Evidence: PMID:9950681 a punctate localization pattern in the corresponding cell bodies
GO:0048471 perinuclear region of cytoplasm	IDA PMID:9950681 Two heteromeric kinesin complexes in chemosensory neurons an...	ACCEPT	Summary: OSM-3 shows punctate localization in the perinuclear region of chemosensory neuron cell bodies (PMID:9950681). Reason: Detailed localization consistent with autoinhibited motor waiting to be recruited to IFT. Supporting Evidence: PMID:9950681 a punctate localization pattern in the corresponding cell bodies
GO:0046626 regulation of insulin receptor signaling pathway	IGI PMID:11381260 Regulation of the Caenorhabditis elegans longevity protein D...	MARK AS OVER ANNOTATED	Summary: This annotation is based on genetic interactions affecting DAF-16 regulation and lifespan. The study shows sensory neurons affect DAF-16 localization and aging, but OSM-3's role is indirect through ciliary function (PMID:11381260). Reason: The connection to insulin signaling is indirect. OSM-3 mutations cause ciliary defects that affect sensory neuron function. Sensory neurons in turn regulate insulin signaling. OSM-3 does not directly regulate insulin receptor signaling; it enables proper ciliary function in sensory neurons. Supporting Evidence: PMID:11381260 Regulation of the Caenorhabditis elegans longevity protein DAF-16 by insulin/IGF-1 and germline signaling.

Core Functions

OSM-3 is a homodimeric kinesin-2 motor that moves processively toward microtubule plus-ends at approximately 1.3 um/s in vivo. It cooperates with heterotrimeric kinesin-II in the middle segment (doublet MTs) and functions alone in the distal segment (singlet MTs) of sensory cilia.

Molecular Function:

plus-end-directed microtubule motor activity

Directly Involved In:

intraciliary anterograde transport cilium assembly

Cellular Locations:

non-motile cilium ciliary basal body axoneme

OSM-3 hydrolyzes ATP to power its motor activity with a basal rate of approximately 4 ATP/s/head that increases dramatically (to approximately 70-75 ATP/s/head) when autoinhibition is relieved by cargo binding or hinge mutations. This autoinhibitory mechanism is essential for proper OSM-3 function in vivo.

Molecular Function:

ATP hydrolysis activity

References

GO_REF:0000002

Gene Ontology annotation through association of InterPro records with GO terms

GO_REF:0000033

Annotation inferences using phylogenetic trees

GO_REF:0000043

Gene Ontology annotation based on UniProtKB/Swiss-Prot keyword mapping

GO_REF:0000044

Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt

GO_REF:0000108

Automatic assignment of GO terms using logical inference, based on on inter-ontology links

GO_REF:0000117

Electronic Gene Ontology annotations created by ARBA machine learning models

GO_REF:0000120

Combined Automated Annotation using Multiple IEA Methods

PMID:11381260

Regulation of the Caenorhabditis elegans longevity protein DAF-16 by insulin/IGF-1 and germline signaling.

PMID:17000874

Autoinhibition regulates the motility of the C. elegans intraflagellar transport motor OSM-3.

OSM-3 is autoinhibited in compact conformation with low ATPase activity

"displays low microtubule-stimulated adenosine triphosphatase (ATPase) activity"
OSM-3 is a plus-end directed processive motor when activated

"As expected, OSM-3 was an active plus end-directed motor in a microtubule gliding assay"

PMID:17000880

Mechanism of transport of IFT particles in C. elegans cilia by the concerted action of kinesin-II and OSM-3 motors.

OSM-3 and kinesin-II cooperate for IFT in middle segment

"heterotrimeric kinesin-II and homodimeric OSM-3-kinesin, which cooperate to move the same intraflagellar transport (IFT) particles along microtubule (MT) doublets"
OSM-3 forms homodimeric kinesin complexes

"heterotrimeric kinesin-II and homodimeric OSM-3-kinesin"

PMID:1732156

Genetic analysis of chemosensory control of dauer formation in Caenorhabditis elegans.

osm-3 mutations cause structurally defective chemosensory cilia

"Dauer-defective mutations in nine genes cause structurally defective chemosensory cilia, thereby blocking chemosensation"

PMID:17420466

Mutation of the MAP kinase DYF-5 affects docking and undocking of kinesin-2 motors and reduces their speed in the cilia of Caenorhabditis elegans.

OSM-3 functions with kinesin-II in middle segment IFT

"anterograde intraflagellar transport (IFT) is mediated by two kinesin-2 complexes, kinesin II and OSM-3 kinesin"
OSM-3 alone mediates distal segment IFT

"OSM-3 alone mediates transport in the distal segments"

PMID:22342749

Endocytosis genes facilitate protein and membrane transport in C. elegans sensory cilia.

PMID:22922713

The BBSome controls IFT assembly and turnaround in cilia.

PMID:26863025

A Screen for Modifiers of Cilia Phenotypes Reveals Novel MKS Alleles and Uncovers a Specific Genetic Interaction between osm-3 and nphp-4.

PMID:27623382

A Conserved Role for Girdin in Basal Body Positioning and Ciliogenesis.

PMID:7828815

Multiple chemosensory defects in daf-11 and daf-21 mutants of Caenorhabditis elegans.

PMID:9950681

Two heteromeric kinesin complexes in chemosensory neurons and sensory cilia of Caenorhabditis elegans.

OSM-3 forms homodimeric kinesin complexes (CeOsm-3)

"heterotrimeric CeKinesin-II and dimeric CeOsm-3"
OSM-3 localizes to amphid, inner labial, and phasmid neurons

"both CeKinesin-II and CeOsm-3 are expressed in amphid, inner labial, and phasmid chemosensory neurons"

file:worm/osm-3/osm-3-deep-research-falcon.md

Deep research report on osm-3

📚 Additional Documentation

Deep Research Falcon

(osm-3-deep-research-falcon.md)

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gene_id: osm-3
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gene_info: Name=osm-3 {ECO:0000312|WormBase:M02B7.3b}; ORFNames=M02B7.3 {ECO:0000312|WormBase:M02B7.3b};
organism_full: Caenorhabditis elegans.
protein_family: Belongs to the TRAFAC class myosin-kinesin ATPase
protein_domains: Kinesin-like_fam. (IPR027640); Kinesin_motor_CS. (IPR019821); Kinesin_motor_dom.
(IPR001752); Kinesin_motor_dom_sf. (IPR036961); P-loop_NTPase. (IPR027417)
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Question

Gene Research for Functional Annotation

⚠️ CRITICAL: Gene/Protein Identification Context

BEFORE YOU BEGIN RESEARCH: You MUST verify you are researching the CORRECT gene/protein. Gene symbols can be ambiguous, especially for less well-characterized genes from non-model organisms.

Target Gene/Protein Identity (from UniProt):

UniProt Accession: P46873
Protein Description: RecName: Full=Osmotic avoidance abnormal protein 3; AltName: Full=Kinesin-like protein osm-3;
Gene Information: Name=osm-3 {ECO:0000312|WormBase:M02B7.3b}; ORFNames=M02B7.3 {ECO:0000312|WormBase:M02B7.3b};
Organism (full): Caenorhabditis elegans.
Protein Family: Belongs to the TRAFAC class myosin-kinesin ATPase
Key Domains: Kinesin-like_fam. (IPR027640); Kinesin_motor_CS. (IPR019821); Kinesin_motor_dom. (IPR001752); Kinesin_motor_dom_sf. (IPR036961); P-loop_NTPase. (IPR027417)

MANDATORY VERIFICATION STEPS:

Check if the gene symbol "osm-3" matches the protein description above
Verify the organism is correct: Caenorhabditis elegans.
Check if protein family/domains align with what you find in literature
If you find literature for a DIFFERENT gene with the same or similar symbol, STOP

If Gene Symbol is Ambiguous or You Cannot Find Relevant Literature:

DO NOT PROCEED WITH RESEARCH ON A DIFFERENT GENE. Instead:
- State clearly: "The gene symbol 'osm-3' is ambiguous or literature is limited for this specific protein"
- Explain what you found (e.g., "Found extensive literature on a different gene with the same symbol in a different organism")
- Describe the protein based ONLY on the UniProt information provided above
- Suggest that the protein function can be inferred from domain/family information

Research Target:

Please provide a comprehensive research report on the gene osm-3 (gene ID: osm-3, UniProt: P46873) in worm.

The research report should be a detailed narrative explaining the function, biological processes, and localization of the gene product. Citations should be given for all claims.

You should prioritize authoritative reviews and primary scientific literature when conducting research. You can supplement
this with annotations you find in gene/protein databases, but these can be outdated or inaccurate.

We are specifically interested in the primary function of the gene - for enzymes, what reaction is catalyzed, and what is the substrate specificity? For transporters, what is the substrate? For structural proteins or adapters, what is the broader structural role? For signaling molecules, what is the role in the pathway.

We are interested in where in or outside the cell the gene product carries out its function.

We are also interested in the signaling or biochemical pathways in which the gene functions. We are less interested in broad pleiotropic effects, except where these elucidate the precise role.

Include evidence where possible. We are interested in both experimental evidence as well as inference from structure, evolution, or bioinformatic analysis. Precise studies should be prioritized over high-throughput, where available.

Output

Question: You are an expert researcher providing comprehensive, well-cited information.

Provide detailed information focusing on:
1. Key concepts and definitions with current understanding
2. Recent developments and latest research (prioritize 2023-2024 sources)
3. Current applications and real-world implementations
4. Expert opinions and analysis from authoritative sources
5. Relevant statistics and data from recent studies

Format as a comprehensive research report with proper citations. Include URLs and publication dates where available.
Always prioritize recent, authoritative sources and provide specific citations for all major claims.

Gene Research for Functional Annotation

⚠️ CRITICAL: Gene/Protein Identification Context

BEFORE YOU BEGIN RESEARCH: You MUST verify you are researching the CORRECT gene/protein. Gene symbols can be ambiguous, especially for less well-characterized genes from non-model organisms.

Target Gene/Protein Identity (from UniProt):

UniProt Accession: P46873
Protein Description: RecName: Full=Osmotic avoidance abnormal protein 3; AltName: Full=Kinesin-like protein osm-3;
Gene Information: Name=osm-3 {ECO:0000312|WormBase:M02B7.3b}; ORFNames=M02B7.3 {ECO:0000312|WormBase:M02B7.3b};
Organism (full): Caenorhabditis elegans.
Protein Family: Belongs to the TRAFAC class myosin-kinesin ATPase
Key Domains: Kinesin-like_fam. (IPR027640); Kinesin_motor_CS. (IPR019821); Kinesin_motor_dom. (IPR001752); Kinesin_motor_dom_sf. (IPR036961); P-loop_NTPase. (IPR027417)

MANDATORY VERIFICATION STEPS:

Check if the gene symbol "osm-3" matches the protein description above
Verify the organism is correct: Caenorhabditis elegans.
Check if protein family/domains align with what you find in literature
If you find literature for a DIFFERENT gene with the same or similar symbol, STOP

If Gene Symbol is Ambiguous or You Cannot Find Relevant Literature:

Research Target:

Please provide a comprehensive research report on the gene osm-3 (gene ID: osm-3, UniProt: P46873) in worm.

The research report should be a detailed narrative explaining the function, biological processes, and localization of the gene product. Citations should be given for all claims.

We are interested in where in or outside the cell the gene product carries out its function.

We are also interested in the signaling or biochemical pathways in which the gene functions. We are less interested in broad pleiotropic effects, except where these elucidate the precise role.

Research plan and verification
We verified the target gene/protein identity before research: OSM-3 in Caenorhabditis elegans is a homodimeric kinesin-2 family motor that powers anterograde intraflagellar transport (IFT) in sensory cilia, cooperating with heterotrimeric kinesin-II; this matches UniProt P46873 and its kinesin/P-loop NTPase domains (kinesin motor domain, P-loop NTPase) (Sep 2006, J Cell Biol; URL: https://doi.org/10.1083/jcb.200606003) (pan2006mechanismoftransport pages 1-2). Segmental roles and velocities reported in amphid/phasmid cilia further support correct identity (Unknown journal, 2009) (inglis2009intraflagellartransportin pages 28-33).

Comprehensive research report: C. elegans osm-3 (UniProt: P46873)

1) Key concepts and definitions
- Definition and family: OSM-3 is a kinesin-2 family motor that forms a homodimer and hydrolyzes ATP via its P-loop NTPase motor domain to move toward microtubule plus ends. In C. elegans ciliated sensory neurons, OSM-3 functions as an anterograde IFT motor; heterotrimeric kinesin-II is the other anterograde IFT motor, and both motors can transport the same IFT particles in vivo (Sep 2006, J Cell Biol; URL: https://doi.org/10.1083/jcb.200606003) (pan2006mechanismoftransport pages 1-2). Reviews and summaries of C. elegans IFT likewise identify OSM-3 as the homodimeric kinesin-2 ortholog of vertebrate KIF17 (Unknown journal, 2012) (broekhuis2012ciliarylengthcontrol pages 103-110).
- Localization and ciliary segmentation: Amphid and phasmid cilia are organized into a proximal transition zone, a middle segment built on doublet microtubules, and a distal segment built on singlet microtubules. OSM-3 and kinesin-II cooperate in the middle segment, while OSM-3 alone extends and traffics within the distal singlet segment (Sep 2006, J Cell Biol; URL: https://doi.org/10.1083/jcb.200606003) (pan2006mechanismoftransport pages 1-2). Segment-specific transport has been quantified using fluorescent IFT reporters in live animals (Unknown journal, 2009) (inglis2009intraflagellartransportin pages 91-96).
- Core pathway: IFT comprises IFT-A and IFT-B subcomplexes, BBSome adaptors, anterograde kinesins (kinesin-II, OSM-3), and retrograde dynein-2. BBS proteins help hold IFT-A and IFT-B trains together and coordinate motor action with OSM-3/kinesin-II (Sep 2006, J Cell Biol; URL: https://doi.org/10.1083/jcb.200606003) (pan2006mechanismoftransport pages 1-2).

2) Recent developments and latest research (2023–2024 priority)
- Handling of hyperactive OSM-3 by neurons and glia (EMBO J, May 2024): A constitutively active OSM-3 (OSM-3CA; hinge/stalk mutation G444E) is excluded from cilia in vivo, released via membrane abscission from neurite tips, and engulfed by neighboring glia in a CED-1–dependent manner. Intragenic suppressors in the OSM-3 motor domain and genetic inhibition of the ciliary kinase DYF-5 restore ciliary localization/structure in OSM-3CA animals. Findings support a model of intramolecular autoinhibition relieved by cargo/regulators at the ciliary base and reveal neuron–glia cooperation to dispose of hyperactive kinesins (EMBO J; URL: https://doi.org/10.1038/s44318-024-00118-0) (xie2024neuronsdisposeof pages 1-2, xie2024neuronsdisposeof pages 12-13, xie2024neuronsdisposeof pages 29-30).
- Segmental import and regulation revealed by rigor/hyperactive mutants (EMBO J, May 2024): A rigor OSM-3G235A binds microtubules but does not undergo IFT and is restricted to the middle segment; when kinesin-II is impaired (klp-11 null), the rigor mutant fails to enter cilia, indicating kinesin-II–dependent import/localization of specific OSM-3 states. DYF-5 kinase modulates OSM-3 activity and distal-segment formation, consistent with earlier suggestions that MAP kinase signaling affects kinesin-II/OSM-3 coordination (EMBO J; URL: https://doi.org/10.1038/s44318-024-00118-0) (xie2024neuronsdisposeof pages 12-13, xie2024neuronsdisposeof pages 1-2).

3) Current applications and real-world implementations
- Genetic and live-imaging dissection of IFT: OSM-3 fluorescent knock-ins and engineered mutants (e.g., G444E hyperactive; G235A rigor) are used to quantify motility, segmental distribution, and regulatory dependencies, enabling rigorous assessment of motor coordination, IFT train composition, and quality-control pathways in vivo. Suppressor screens using dye-filling (DiI) identify modifiers of motor hyperactivity and provide candidate regulatory mechanisms linking motor conformational state to ciliary entry and glial clearance (EMBO J, 2024; URL: https://doi.org/10.1038/s44318-024-00118-0) (xie2024neuronsdisposeof pages 29-30, xie2024neuronsdisposeof pages 1-2).
- Model for human ciliopathies and KIF17 function: Because OSM-3 is the C. elegans counterpart of KIF17, OSM-3-based assays are used to study how BBSome/IFT modules coordinate with motors, how segmental architecture emerges from motor specialization, and how dysregulation alters ciliary signaling—principles applicable to human cilia biology (Mol Biol Cell, 2007) (ou2007sensoryciliogenesisin pages 14-15).

4) Expert opinions and analysis from authoritative sources
- Motor cooperation model: In vitro gliding assays and in vivo imaging support mechanical competition/coordination between kinesin-II (slow) and OSM-3 (fast) on the same IFT particles, with BBS proteins contributing to tension and train integrity. Quantitative modeling and genetic separations (bbs mutants) support this view (Sep 2006, J Cell Biol; URL: https://doi.org/10.1083/jcb.200606003) (pan2006mechanismoftransport pages 1-2).
- Modular regulation of OSM-3 docking and activation: Genetic analyses place DYF-1 and DYF-13 as OSM-3 modulators that promote docking/activation on IFT trains and distal-segment assembly, while emphasizing that cargo modules can exhibit dynamics distinct from core IFT particles; disruptions may impair function without overtly altering IFT motility (May 2007, Mol Biol Cell; URL: https://doi.org/10.1091/mbc.e06-09-0805) (ou2007sensoryciliogenesisin pages 14-15).
- Segment-specific redundancy and specialization: Kinesin-II and OSM-3 are redundant in the middle segment but OSM-3 is uniquely required for distal singlet microtubule extension; double mutants lacking both motors abrogate cilium formation, establishing the division of labor across ciliary segments (Unknown journal, 2009; Sep 2006, J Cell Biol) (inglis2009intraflagellartransportin pages 28-33, pan2006mechanismoftransport pages 1-2).

5) Relevant statistics and data from recent and classic studies
- Ciliary architecture and segmental lengths (amphid): transition zone ~1 μm, middle/doublets ~4 μm, distal/singlets ~2.5 μm (Sep 2006, J Cell Biol; URL: https://doi.org/10.1083/jcb.200606003) (pan2006mechanismoftransport pages 1-2).
- Anterograde transport velocities: kinesin-II alone ~0.5 μm/s; OSM-3 alone ~1.2–1.3 μm/s; combined in middle segment ~0.7–0.74 μm/s; distal IFT speeds ~1.15–1.21 μm/s in vivo (Sep 2006, J Cell Biol; Unknown journal, 2009; Unknown journal, 2012) (pan2006mechanismoftransport pages 1-2, inglis2009intraflagellartransportin pages 91-96, broekhuis2012ciliarylengthcontrol pages 103-110).
- Segmental roles and mutant phenotypes: osm-3 mutants lack distal segments and exhibit dye-filling (Dyf) defects and impaired osmotic avoidance/chemosensory behaviors; osm-3; kinesin-II double mutants fail to build cilia (Unknown journal, 2009; Sep 2006, J Cell Biol) (inglis2009intraflagellartransportin pages 28-33, pan2006mechanismoftransport pages 1-2).
- BBS-dependent train separation and speeds: in bbs-7/-8 mutants, kinesin-II/IFT-A move at ~0.5 μm/s and OSM-3/IFT-B at ~1.3 μm/s, indicating BBSome roles in coupling IFT-A/B and coordinating motor action (Sep 2006, J Cell Biol; URL: https://doi.org/10.1083/jcb.200606003) (pan2006mechanismoftransport pages 1-2).
- 2024 suppressor screen and quantitative assays: Dye-filling screen size N≈≥100 animals per genotype; microtubule gliding velocities for OSM-3 suppressor mutants quantified via Gaussian fits (e.g., ~0.98 ± 0.17 μm/s, ~1.12 ± 0.11 μm/s), and SEC-MALS/LC-MS used to assess biochemical states (May 2024, EMBO J; URL: https://doi.org/10.1038/s44318-024-00118-0) (xie2024neuronsdisposeof pages 29-30).

Mechanism, substrates/cargo, and regulation
- Biochemical activity: As a kinesin motor, OSM-3 catalyzes ATP hydrolysis to step along axonemal microtubules, transporting IFT complexes and cargo anterogradely toward ciliary tips (Sep 2006, J Cell Biol; URL: https://doi.org/10.1083/jcb.200606003) (pan2006mechanismoftransport pages 1-2).
- Cargo and association: OSM-3 is tightly coupled to IFT-B complexes and, through BBS proteins, to IFT-A, enabling unified IFT trains; in bbs mutants, the complexes and motors segregate into distinct trains with distinct speeds (Sep 2006, J Cell Biol; URL: https://doi.org/10.1083/jcb.200606003) (pan2006mechanismoftransport pages 1-2). Regulatory adaptors DYF-1 and DYF-13 promote OSM-3 docking/activation and distal segment assembly; other cargo modules can affect function without overtly changing core IFT motility (May 2007, Mol Biol Cell; URL: https://doi.org/10.1091/mbc.e06-09-0805) (ou2007sensoryciliogenesisin pages 14-15).
- Regulation and signaling: Evidence supports intramolecular autoinhibition of OSM-3 relieved at the ciliary base; DYF-5 (a MAPK) modulates motor activity and the division of labor with kinesin-II, and hyperactive OSM-3 triggers a neuron–glia disposal program via CED-1–dependent engulfment (May 2024, EMBO J; URL: https://doi.org/10.1038/s44318-024-00118-0) (xie2024neuronsdisposeof pages 1-2, xie2024neuronsdisposeof pages 12-13). Segmental transport rates and coupling with kinesin-II reflect mechanical coordination that can be tuned by IFT train composition and BBSome-dependent tension (Sep 2006, J Cell Biol; URL: https://doi.org/10.1083/jcb.200606003) (pan2006mechanismoftransport pages 1-2).

Cellular/organismal phenotypes and localization
- Localization: OSM-3 localizes to cilia of amphid and phasmid neurons and exhibits segment-specific transport behavior—cooperative in the middle segment and OSM-3-only in the distal segment (Sep 2006, J Cell Biol; Unknown journal, 2009) (pan2006mechanismoftransport pages 1-2, inglis2009intraflagellartransportin pages 91-96).
- Phenotypes: osm-3 loss leads to distal segment defects and Dyf phenotypes, correlating with impaired osmotic avoidance and other sensory behaviors; removal of both OSM-3 and kinesin-II eliminates cilia (Unknown journal, 2009; Sep 2006, J Cell Biol) (inglis2009intraflagellartransportin pages 28-33, pan2006mechanismoftransport pages 1-2).

Embedded summary table of key facts and sources
| Aspect | Finding/Statistic | Evidence Source (year, journal) | URL |
|---|---|---:|---|
| Identity | Kinesin-2 homodimer (OSM-3); kinesin-like P-loop NTPase motor protein | Pan et al., 2006, J Cell Biol (pan2006mechanismoftransport pages 1-2); Inglis, 2009 (inglis2009intraflagellartransportin pages 28-33) | https://doi.org/10.1083/jcb.200606003; n/a |
| Cellular localization | Localizes to sensory cilia of amphid and phasmid neurons; functions in axoneme middle (doublet) and distal (singlet) segments | Pan et al., 2006, J Cell Biol (pan2006mechanismoftransport pages 1-2); Inglis, 2009 (inglis2009intraflagellartransportin pages 91-96) | https://doi.org/10.1083/jcb.200606003; n/a |
| Primary function | Drives anterograde intraflagellar transport (IFT) of IFT particles; cooperates with heterotrimeric kinesin-II to move shared IFT trains | Pan et al., 2006, J Cell Biol (pan2006mechanismoftransport pages 1-2); Ou et al., 2007, Mol Biol Cell (ou2007sensoryciliogenesisin pages 14-15) | https://doi.org/10.1083/jcb.200606003; https://doi.org/10.1091/mbc.e06-09-0805 |
| Segment-specific roles | Kinesin-II + OSM-3 operate in middle segment (produce intermediate speed); OSM-3 alone powers faster distal-segment transport and extends distal singlets; osm-3 mutants lack distal segments | Pan et al., 2006, J Cell Biol (pan2006mechanismoftransport pages 1-2); Inglis, 2009 (inglis2009intraflagellartransportin pages 91-96) | https://doi.org/10.1083/jcb.200606003; n/a |
| Transport velocities | kinesin-II ≈ 0.5 μm/s; OSM-3 ≈ 1.2–1.3 μm/s; combined (middle) ≈ 0.7–0.74 μm/s; distal speeds reported ≈ 1.15–1.21 μm/s (mean ± SD shown in studies) | Pan et al., 2006, J Cell Biol (pan2006mechanismoftransport pages 1-2); Inglis, 2009 (inglis2009intraflagellartransportin pages 91-96); Broekhuis, 2012 (broekhuis2012ciliarylengthcontrol pages 103-110) | https://doi.org/10.1083/jcb.200606003; n/a; n/a |
| Cargo / regulatory modules | IFT-A/B coupling mediated by BBS proteins; DYF-1 and DYF-13 implicated in OSM-3 docking/activation; DYF-5 (MAPK) implicated in undocking/regulation of kinesin-II/OSM-3 coordination | Ou et al., 2007, Mol Biol Cell (ou2007sensoryciliogenesisin pages 14-15); Pan et al., 2006, J Cell Biol (pan2006mechanismoftransport pages 1-2) | https://doi.org/10.1091/mbc.e06-09-0805; https://doi.org/10.1083/jcb.200606003 |
| Phenotypes | Dye-filling (Dyf) defects, impaired osmotic avoidance and chemosensation, shortened or missing distal ciliary segments, altered cilium structure and function in osm-3 mutants | Inglis, 2009 (inglis2009intraflagellartransportin pages 91-96); Pan et al., 2006, J Cell Biol (pan2006mechanismoftransport pages 1-2) | n/a; https://doi.org/10.1083/jcb.200606003 |
| Recent (2023–2024) findings | Acute IFT modulation alters sensory response dynamics; neurons dispose of hyperactive OSM-3 via membrane abscission and glial engulfment; intragenic suppressors and DYF-5 modulate hyperactive OSM-3 phenotypes (Xie et al., 2024) | Xie et al., 2024, EMBO J (xie2024neuronsdisposeof pages 12-13, xie2024neuronsdisposeof pages 29-30) | https://doi.org/10.1038/s44318-024-00118-0 |
| Experimental statistics | Dye-filling suppressor screen N ≥ 100 (Xie 2024); OSM-3 distal velocity WT ~1.17 ± 0.21 μm/s (n=152) reported in cilium-length analyses; middle ≈ 0.74 μm/s vs distal ≈ 1.15 μm/s in IFT assays | Xie et al., 2024 (xie2024neuronsdisposeof pages 29-30); Broekhuis, 2012 (broekhuis2012ciliarylengthcontrol pages 103-110); Inglis, 2009 (inglis2009intraflagellartransportin pages 91-96) | https://doi.org/10.1038/s44318-024-00118-0; n/a; n/a |
| Applications | OSM-3 serves as a tractable model for KIF17-like motors and for dissecting IFT mechanisms and ciliopathy-relevant processes (motor coordination, BBS-module function, IFT cargo dynamics) | Ou et al., 2007, Mol Biol Cell (ou2007sensoryciliogenesisin pages 14-15); Broekhuis, 2012 (broekhuis2012ciliarylengthcontrol pages 103-110) | https://doi.org/10.1091/mbc.e06-09-0805; n/a |

Table: Concise, evidence-linked summary table of OSM-3 identity, localization, function, kinetics, regulation, phenotypes, recent 2023–24 findings, experimental statistics, and applications, with primary references from the gathered corpus (context IDs) and URLs where available.

Conclusions
OSM-3 (UniProt P46873) is the homodimeric kinesin-2 motor that drives anterograde IFT in C. elegans sensory cilia. It cooperates with kinesin-II in middle segments and acts alone in distal segments to extend singlet microtubules. Transport velocities, segmental specialization, and BBSome-dependent coupling of IFT-A/B define its mechanistic role. Recent (2024) work reveals neuron–glia quality control that clears hyperactive OSM-3 and identifies DYF-5 and intragenic changes as key regulators of OSM-3 conformation, ciliary entry, and distal-segment formation. These insights consolidate OSM-3 as a central, regulated driver of ciliary assembly and signaling, and as a model for conserved KIF17 function in metazoan cilia (Sep 2006, J Cell Biol; May 2007, Mol Biol Cell; Unknown journal, 2009; May 2024, EMBO J) (pan2006mechanismoftransport pages 1-2, ou2007sensoryciliogenesisin pages 14-15, inglis2009intraflagellartransportin pages 28-33, xie2024neuronsdisposeof pages 12-13, xie2024neuronsdisposeof pages 1-2, xie2024neuronsdisposeof pages 29-30).

References

(pan2006mechanismoftransport pages 1-2): Xiaoyu Pan, Guangshuo Ou, Gul Civelekoglu-Scholey, Oliver E. Blacque, Nicholas F. Endres, Li Tao, Alex Mogilner, Michel R. Leroux, Ronald D. Vale, and Jonathan M. Scholey. Mechanism of transport of ift particles in c. elegans cilia by the concerted action of kinesin-ii and osm-3 motors. The Journal of Cell Biology, 174:1035-1045, Sep 2006. URL: https://doi.org/10.1083/jcb.200606003, doi:10.1083/jcb.200606003. This article has 239 citations.
(inglis2009intraflagellartransportin pages 28-33): PN Inglis. Intraflagellar transport in caenorhabditis elegans: identification of novel proteins and behavioural functions. Unknown journal, 2009.
(broekhuis2012ciliarylengthcontrol pages 103-110): J Broekhuis. Ciliary length control. Unknown journal, 2012.
(inglis2009intraflagellartransportin pages 91-96): PN Inglis. Intraflagellar transport in caenorhabditis elegans: identification of novel proteins and behavioural functions. Unknown journal, 2009.
(xie2024neuronsdisposeof pages 1-2): Chao Xie, Guanghan Chen, Ming Li, Peng Huang, Zhe Chen, Kexin Lei, Dong Li, Yuhe Wang, Augustine Cleetus, Mohamed AA Mohamed, Punam Sonar, Wei Feng, Zeynep Ökten, and Guangshuo Ou. Neurons dispose of hyperactive kinesin into glial cells for clearance. The EMBO Journal, 43:2606-2635, May 2024. URL: https://doi.org/10.1038/s44318-024-00118-0, doi:10.1038/s44318-024-00118-0. This article has 9 citations.
(xie2024neuronsdisposeof pages 12-13): Chao Xie, Guanghan Chen, Ming Li, Peng Huang, Zhe Chen, Kexin Lei, Dong Li, Yuhe Wang, Augustine Cleetus, Mohamed AA Mohamed, Punam Sonar, Wei Feng, Zeynep Ökten, and Guangshuo Ou. Neurons dispose of hyperactive kinesin into glial cells for clearance. The EMBO Journal, 43:2606-2635, May 2024. URL: https://doi.org/10.1038/s44318-024-00118-0, doi:10.1038/s44318-024-00118-0. This article has 9 citations.
(xie2024neuronsdisposeof pages 29-30): Chao Xie, Guanghan Chen, Ming Li, Peng Huang, Zhe Chen, Kexin Lei, Dong Li, Yuhe Wang, Augustine Cleetus, Mohamed AA Mohamed, Punam Sonar, Wei Feng, Zeynep Ökten, and Guangshuo Ou. Neurons dispose of hyperactive kinesin into glial cells for clearance. The EMBO Journal, 43:2606-2635, May 2024. URL: https://doi.org/10.1038/s44318-024-00118-0, doi:10.1038/s44318-024-00118-0. This article has 9 citations.
(ou2007sensoryciliogenesisin pages 14-15): Guangshuo Ou, Makato Koga, Oliver E. Blacque, Takashi Murayama, Yasumi Ohshima, Jenny C. Schafer, Chunmei Li, Bradley K. Yoder, Michel R. Leroux, and Jonathan M. Scholey. Sensory ciliogenesis in caenorhabditis elegans: assignment of ift components into distinct modules based on transport and phenotypic profiles. Molecular biology of the cell, 18 5:1554-69, May 2007. URL: https://doi.org/10.1091/mbc.e06-09-0805, doi:10.1091/mbc.e06-09-0805. This article has 175 citations and is from a domain leading peer-reviewed journal.

Citations

pan2006mechanismoftransport pages 1-2
inglis2009intraflagellartransportin pages 28-33
broekhuis2012ciliarylengthcontrol pages 103-110
inglis2009intraflagellartransportin pages 91-96
ou2007sensoryciliogenesisin pages 14-15
xie2024neuronsdisposeof pages 29-30
xie2024neuronsdisposeof pages 1-2
xie2024neuronsdisposeof pages 12-13
https://doi.org/10.1083/jcb.200606003
https://doi.org/10.1038/s44318-024-00118-0
https://doi.org/10.1091/mbc.e06-09-0805
https://doi.org/10.1083/jcb.200606003;
https://doi.org/10.1091/mbc.e06-09-0805;
https://doi.org/10.1038/s44318-024-00118-0;
https://doi.org/10.1083/jcb.200606003,
https://doi.org/10.1038/s44318-024-00118-0,
https://doi.org/10.1091/mbc.e06-09-0805,

📄 View Raw YAML

id: P46873
gene_symbol: osm-3
product_type: PROTEIN
status: COMPLETE
taxon:
  id: NCBITaxon:6239
  label: Caenorhabditis elegans
description: OSM-3 is a homodimeric kinesin-2 family motor protein essential for
  intraflagellar transport (IFT) in C. elegans sensory cilia. It functions 
  cooperatively with heterotrimeric kinesin-II to drive anterograde IFT in the 
  middle segment of cilia, and is the sole motor for IFT in the distal segment 
  where it builds the distal singlet microtubule region. OSM-3 is autoinhibited 
  in a folded conformation and is activated upon binding to IFT particles. It is
  expressed exclusively in 26 chemosensory neurons (amphid, inner labial, and 
  phasmid neurons). OSM-3 mutants have truncated cilia lacking distal segments 
  and show defects in osmotic avoidance, chemotaxis, and dauer formation.
existing_annotations:
  - term:
      id: GO:0005737
      label: cytoplasm
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: OSM-3 localizes to the cytoplasm including perinuclear regions 
        and cell bodies of chemosensory neurons, where it exists in an 
        autoinhibited compact conformation before being recruited to IFT 
        particles (PMID:9950681, PMID:17000874).
      action: ACCEPT
      reason: IBA annotation is phylogenetically well-supported. OSM-3 is 
        present in the cytoplasm of neurons prior to ciliary entry, consistent 
        with its autoinhibition mechanism.
      supported_by:
        - reference_id: PMID:9950681
          supporting_text: a punctate localization pattern in the corresponding 
            cell bodies and dendrites
        - reference_id: PMID:17000874
          supporting_text: OSM-3 exists in the cytoplasm in a compact, 
            autoinhibited state and that binding to an IFT particle relieves 
            this autoinhibition
        - reference_id: file:worm/osm-3/osm-3-deep-research-falcon.md
          supporting_text: 'model: Edison Scientific Literature'
  - term:
      id: GO:0005871
      label: kinesin complex
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: OSM-3 forms a homodimeric kinesin complex that functions as part 
        of the IFT machinery in sensory cilia (PMID:9950681, PMID:17000874).
      action: ACCEPT
      reason: OSM-3 is a dimeric kinesin motor. The IBA annotation is 
        well-supported by phylogenetic evidence and confirmed by experimental 
        data in C. elegans.
      supported_by:
        - reference_id: PMID:9950681
          supporting_text: heterotrimeric CeKinesin-II and dimeric CeOsm-3
  - term:
      id: GO:0005874
      label: microtubule
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: OSM-3 is active along microtubules of the ciliary axoneme, moving
        processively along both doublet microtubules in the middle segment and 
        singlet microtubules in the distal segment (PMID:17000874).
      action: ACCEPT
      reason: Kinesin motors function on microtubules. OSM-3 translocates along 
        axonemal microtubules during IFT.
      supported_by:
        - reference_id: PMID:17000874
          supporting_text: OSM-3 was an active plus end-directed motor in a 
            microtubule gliding assay
  - term:
      id: GO:0008017
      label: microtubule binding
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: OSM-3 binds microtubules as part of its motor activity. The motor
        domain contains conserved microtubule-binding elements characteristic of
        kinesin motors (PMID:17000874).
      action: ACCEPT
      reason: Microtubule binding is an essential property of kinesin motors. 
        OSM-3 has a conserved kinesin motor domain with microtubule-binding 
        capability.
      supported_by:
        - reference_id: PMID:17000874
          supporting_text: OSM-3 was an active plus end-directed motor in a 
            microtubule gliding assay
  - term:
      id: GO:0016887
      label: ATP hydrolysis activity
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: OSM-3 hydrolyzes ATP to power its motor activity. The wild-type 
        protein has a basal ATPase rate of approximately 4 ATP/s/head that 
        increases when autoinhibition is relieved (PMID:17000874).
      action: ACCEPT
      reason: ATP hydrolysis is essential for kinesin motor function. Direct 
        biochemical measurements confirm OSM-3 ATPase activity.
      supported_by:
        - reference_id: PMID:17000874
          supporting_text: low microtubule-stimulated adenosine triphosphatase 
            (ATPase) activity
  - term:
      id: GO:0043005
      label: neuron projection
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: OSM-3 is localized to chemosensory neuron projections including 
        dendrites and their ciliated endings (PMID:9950681).
      action: ACCEPT
      reason: OSM-3 localizes along the dendrites of chemosensory neurons 
        extending to the ciliated endings.
      supported_by:
        - reference_id: PMID:9950681
          supporting_text: a punctate localization pattern in the corresponding 
            cell bodies and dendrites
  - term:
      id: GO:0005929
      label: cilium
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: OSM-3 localizes to sensory cilia where it functions in IFT. It 
        localizes along the full cilium length including both middle and distal 
        segments (PMID:9950681).
      action: ACCEPT
      reason: Core cellular localization for OSM-3 function. IBA is 
        well-supported and confirmed by multiple IDA annotations.
      supported_by:
        - reference_id: PMID:9950681
          supporting_text: an intense concentration of CeKinesin-II and CeOsm-3 
            polypeptides in the ciliated endings of these chemosensory neurons
  - term:
      id: GO:0030030
      label: cell projection organization
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: OSM-3 is required for organizing the distal segment of sensory 
        cilia. Loss of OSM-3 results in cilia lacking distal segments 
        (PMID:17000874).
      action: MODIFY
      reason: While technically accurate, this term is too general. OSM-3 has a 
        specific role in cilium organization, not cell projections broadly.
      proposed_replacement_terms:
        - id: GO:0060271
          label: cilium assembly
        - id: GO:1905515
          label: non-motile cilium assembly
  - term:
      id: GO:0005815
      label: microtubule organizing center
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: OSM-3 localizes to the ciliary basal body, which serves as the 
        MTOC for the cilium (PMID:27623382).
      action: MODIFY
      reason: While basal bodies are MTOCs, the more precise term for OSM-3 
        localization is ciliary basal body, which is experimentally validated.
      proposed_replacement_terms:
        - id: GO:0036064
          label: ciliary basal body
  - term:
      id: GO:0098971
      label: anterograde dendritic transport of neurotransmitter receptor 
        complex
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: This annotation is based on the mammalian homolog KIF17, which 
        transports neurotransmitter receptors in dendrites. However, OSM-3 in C.
        elegans functions primarily in ciliary IFT rather than dendritic 
        receptor transport.
      action: MARK_AS_OVER_ANNOTATED
      reason: This function is established for mammalian KIF17 but not 
        demonstrated for C. elegans OSM-3. OSM-3 is specifically involved in 
        ciliary transport, not general dendritic transport of receptor 
        complexes.
      additional_reference_ids:
        - PMID:17000874
      supported_by:
        - reference_id: PMID:17000874
          supporting_text: Autoinhibition regulates the motility of the C.
  - term:
      id: GO:0008574
      label: plus-end-directed microtubule motor activity
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: OSM-3 is a plus-end directed motor that drives anterograde 
        transport in cilia. This is confirmed by direct in vitro assays 
        (PMID:17000874).
      action: ACCEPT
      reason: Core molecular function of OSM-3. IBA is well-supported and 
        confirmed by IDA.
      supported_by:
        - reference_id: PMID:17000874
          supporting_text: OSM-3 was an active plus end-directed motor in a 
            microtubule gliding assay
  - term:
      id: GO:0000166
      label: nucleotide binding
    evidence_type: IEA
    original_reference_id: GO_REF:0000043
    review:
      summary: OSM-3 binds nucleotides (ATP/ADP) as part of its motor cycle. 
        UniProt annotates ATP binding based on keywords.
      action: ACCEPT
      reason: Correct but less informative than ATP binding. The IEA is 
        acceptable as a broader parent annotation.
  - term:
      id: GO:0003777
      label: microtubule motor activity
    evidence_type: IEA
    original_reference_id: GO_REF:0000120
    review:
      summary: OSM-3 is a microtubule motor that moves along microtubules. This 
        is the general molecular function for kinesin motors.
      action: ACCEPT
      reason: Core molecular function. IEA is appropriate as this is confirmed 
        by experimental data.
      supported_by:
        - reference_id: PMID:17000874
          supporting_text: OSM-3 was an active plus end-directed motor in a 
            microtubule gliding assay
  - term:
      id: GO:0005524
      label: ATP binding
    evidence_type: IEA
    original_reference_id: GO_REF:0000120
    review:
      summary: OSM-3 binds ATP at its motor domain for hydrolysis. The UniProt 
        entry notes the ATP binding site at residues 87-94.
      action: ACCEPT
      reason: Essential molecular function for kinesin motors. Strongly 
        supported by domain analysis and biochemical data.
      supported_by:
        - reference_id: PMID:17000874
          supporting_text: microtubule-stimulated adenosine triphosphatase 
            (ATPase) activity
  - term:
      id: GO:0005856
      label: cytoskeleton
    evidence_type: IEA
    original_reference_id: GO_REF:0000120
    review:
      summary: OSM-3 localizes to the cytoskeleton, specifically the 
        microtubule-based axoneme of cilia.
      action: ACCEPT
      reason: General localization term that is accurate for a microtubule 
        motor.
  - term:
      id: GO:0005874
      label: microtubule
    evidence_type: IEA
    original_reference_id: GO_REF:0000043
    review:
      summary: Duplicate of IBA annotation. OSM-3 is active on microtubules.
      action: ACCEPT
      reason: Correct annotation, duplicates IBA with different evidence code.
  - term:
      id: GO:0005929
      label: cilium
    evidence_type: IEA
    original_reference_id: GO_REF:0000120
    review:
      summary: Duplicate of IBA annotation. OSM-3 localizes to sensory cilia.
      action: ACCEPT
      reason: Correct annotation, duplicates IBA with different evidence code.
  - term:
      id: GO:0005930
      label: axoneme
    evidence_type: IEA
    original_reference_id: GO_REF:0000044
    review:
      summary: OSM-3 localizes to and functions along the ciliary axoneme, 
        transporting IFT particles (PMID:17000874).
      action: ACCEPT
      reason: Correct and specific localization for OSM-3 within the cilium.
  - term:
      id: GO:0007018
      label: microtubule-based movement
    evidence_type: IEA
    original_reference_id: GO_REF:0000120
    review:
      summary: OSM-3 drives microtubule-based movement of IFT particles within 
        cilia.
      action: MODIFY
      reason: While accurate, a more specific term exists for OSM-3's biological
        process.
      proposed_replacement_terms:
        - id: GO:0035720
          label: intraciliary anterograde transport
  - term:
      id: GO:0008017
      label: microtubule binding
    evidence_type: IEA
    original_reference_id: GO_REF:0000002
    review:
      summary: Duplicate of IBA annotation. OSM-3 binds microtubules via its 
        motor domain.
      action: ACCEPT
      reason: Correct annotation, duplicates IBA with different evidence code 
        (InterPro).
  - term:
      id: GO:0032839
      label: dendrite cytoplasm
    evidence_type: IEA
    original_reference_id: GO_REF:0000108
    review:
      summary: This annotation is inferred from the dendritic transport 
        annotation. OSM-3 does localize to dendrites of sensory neurons 
        (PMID:9950681).
      action: ACCEPT
      reason: OSM-3 is present in dendrite cytoplasm en route to cilia.
      supported_by:
        - reference_id: PMID:9950681
          supporting_text: a punctate localization pattern in the corresponding 
            cell bodies and dendrites
  - term:
      id: GO:0032991
      label: protein-containing complex
    evidence_type: IEA
    original_reference_id: GO_REF:0000117
    review:
      summary: OSM-3 forms homodimeric complexes and associates with IFT 
        particles.
      action: MODIFY
      reason: Too general. OSM-3 specifically forms kinesin complexes.
      proposed_replacement_terms:
        - id: GO:0005871
          label: kinesin complex
  - term:
      id: GO:0030425
      label: dendrite
    evidence_type: IDA
    original_reference_id: PMID:9950681
    review:
      summary: OSM-3::GFP localizes to dendrites of chemosensory neurons as 
        shown by immunolocalization (PMID:9950681).
      action: ACCEPT
      reason: Direct experimental evidence from immunolocalization studies.
      supported_by:
        - reference_id: PMID:9950681
          supporting_text: a punctate localization pattern in the corresponding 
            cell bodies and dendrites
  - term:
      id: GO:1902856
      label: negative regulation of non-motile cilium assembly
    evidence_type: IGI
    original_reference_id: PMID:17420466
    review:
      summary: In dyf-5 mutants, OSM-3 accumulates and moves at reduced speed, 
        and cilia become elongated. This suggests complex regulatory 
        interactions affecting cilium length (PMID:17420466).
      action: UNDECIDED
      reason: The relationship between OSM-3 and negative regulation of cilium 
        assembly is indirect and context-dependent (dyf-5 mutant background). 
        OSM-3 primarily promotes cilium assembly; negative regulation may be a 
        secondary effect.
      supported_by:
        - reference_id: PMID:17420466
          supporting_text: Mutation of the MAP kinase DYF-5 affects docking and 
            undocking of kinesin-2 motors and reduces their speed in the cilia 
            of Caenorhabditis elegans.
  - term:
      id: GO:1902857
      label: positive regulation of non-motile cilium assembly
    evidence_type: IGI
    original_reference_id: PMID:17420466
    review:
      summary: OSM-3 is required for assembly of the distal segment of sensory 
        cilia. Loss of OSM-3 results in truncated cilia (PMID:17420466, 
        PMID:17000874).
      action: ACCEPT
      reason: OSM-3 is essential for building distal segments and thus 
        positively regulates cilium assembly.
      supported_by:
        - reference_id: PMID:17420466
          supporting_text: OSM-3 alone mediates transport in the distal segments
        - reference_id: PMID:17000874
          supporting_text: osm-3-null animals only display a loss of the distal 
            segments of their sensory cilia
  - term:
      id: GO:0035720
      label: intraciliary anterograde transport
    evidence_type: IMP
    original_reference_id: PMID:17420466
    review:
      summary: OSM-3 drives anterograde IFT in cilia. Mutations affect IFT 
        velocity and docking/undocking of kinesin motors (PMID:17420466).
      action: ACCEPT
      reason: Core biological function of OSM-3. IMP evidence from dyf-5 mutant 
        studies.
      supported_by:
        - reference_id: PMID:17420466
          supporting_text: anterograde intraflagellar transport (IFT) is 
            mediated by two kinesin-2 complexes, kinesin II and OSM-3 kinesin
  - term:
      id: GO:0035720
      label: intraciliary anterograde transport
    evidence_type: IGI
    original_reference_id: PMID:17420466
    review:
      summary: Genetic interaction with dyf-5 demonstrates OSM-3's role in 
        anterograde IFT.
      action: ACCEPT
      reason: Supports the IMP annotation with genetic interaction evidence.
      supported_by:
        - reference_id: PMID:17420466
          supporting_text: OSM-3 moves at a reduced speed and is not attached to
            IFT particles
  - term:
      id: GO:0036064
      label: ciliary basal body
    evidence_type: IDA
    original_reference_id: PMID:27623382
    review:
      summary: OSM-3 localizes to the ciliary basal body as shown by 
        fluorescence microscopy studies examining basal body positioning 
        (PMID:27623382).
      action: ACCEPT
      reason: Direct experimental localization data from the Girdin study.
      supported_by:
        - reference_id: PMID:27623382
          supporting_text: A Conserved Role for Girdin in Basal Body Positioning
            and Ciliogenesis.
  - term:
      id: GO:0042073
      label: intraciliary transport
    evidence_type: IDA
    original_reference_id: PMID:27623382
    review:
      summary: OSM-3 functions in intraciliary transport as demonstrated by its 
        localization and movement along the ciliary axoneme.
      action: ACCEPT
      reason: Core biological function of OSM-3.
      supported_by:
        - reference_id: PMID:27623382
          supporting_text: A Conserved Role for Girdin in Basal Body Positioning
            and Ciliogenesis.
  - term:
      id: GO:0097730
      label: non-motile cilium
    evidence_type: IDA
    original_reference_id: PMID:17420466
    review:
      summary: OSM-3 localizes to non-motile sensory cilia in C. elegans 
        chemosensory neurons (PMID:17420466).
      action: ACCEPT
      reason: C. elegans sensory cilia are non-motile (primary) cilia. OSM-3 
        localizes to these structures.
      supported_by:
        - reference_id: PMID:17420466
          supporting_text: In the cilia of the nematode Caenorhabditis elegans
  - term:
      id: GO:1902857
      label: positive regulation of non-motile cilium assembly
    evidence_type: IMP
    original_reference_id: PMID:17420466
    review:
      summary: osm-3 mutants lack distal cilium segments, demonstrating OSM-3's 
        role in promoting cilium assembly (PMID:17420466).
      action: ACCEPT
      reason: Mutant phenotype analysis supports positive regulation of cilium 
        assembly.
      supported_by:
        - reference_id: PMID:17420466
          supporting_text: OSM-3 alone mediates transport in the distal segments
  - term:
      id: GO:0035720
      label: intraciliary anterograde transport
    evidence_type: IDA
    original_reference_id: PMID:17000874
    review:
      summary: Single-molecule analysis demonstrates OSM-3 is a processive motor
        capable of anterograde transport when autoinhibition is relieved 
        (PMID:17000874).
      action: ACCEPT
      reason: Direct in vitro demonstration of OSM-3 motor activity consistent 
        with anterograde IFT function.
      supported_by:
        - reference_id: PMID:17000874
          supporting_text: OSM-3 is a Kinesin-2 family member from 
            Caenorhabditis elegans that is involved in intraflagellar transport 
            (IFT), a process essential for the construction and maintenance of 
            sensory cilia
  - term:
      id: GO:0035720
      label: intraciliary anterograde transport
    evidence_type: IDA
    original_reference_id: PMID:17000880
    review:
      summary: Live imaging shows OSM-3 and kinesin-II cooperatively drive 
        anterograde IFT in the middle segment, while OSM-3 alone transports in 
        the distal segment (PMID:17000880).
      action: ACCEPT
      reason: Definitive demonstration of OSM-3's role in anterograde IFT 
        through live imaging studies.
      supported_by:
        - reference_id: PMID:17000874
          supporting_text: Microscopy studies in living C. elegans have shown 
            that both motors cooperate to move IFT particles along the middle 
            segment of the cilia
        - reference_id: PMID:17000880
          supporting_text: Mechanism of transport of IFT particles in C.
  - term:
      id: GO:0035720
      label: intraciliary anterograde transport
    evidence_type: IMP
    original_reference_id: PMID:26863025
    review:
      summary: osm-3 mutations affect IFT velocity in cilia, with the yhw66 
        allele reducing anterograde IFT rates (PMID:26863025).
      action: ACCEPT
      reason: Mutant phenotype analysis confirms OSM-3's role in anterograde 
        IFT.
      supported_by:
        - reference_id: PMID:26863025
          supporting_text: In osm-3(yhw66) mutants anterograde intraflagellar 
            transport (IFT) velocity is reduced
  - term:
      id: GO:1905515
      label: non-motile cilium assembly
    evidence_type: IGI
    original_reference_id: PMID:26863025
    review:
      summary: Genetic interactions between osm-3 and nphp-4 affect distal 
        segment formation of non-motile cilia (PMID:26863025).
      action: ACCEPT
      reason: Genetic interaction data supports OSM-3's role in cilium assembly.
      supported_by:
        - reference_id: PMID:26863025
          supporting_text: nphp-4(tm925);osm-3(yhw66) double mutants lack distal
            segments and are dye-filling (Dyf) and osmotic avoidance (Osm) 
            defective, similar to osm-3(mn357) null mutants
  - term:
      id: GO:0061066
      label: positive regulation of dauer larval development
    evidence_type: IMP
    original_reference_id: PMID:7828815
    review:
      summary: osm-3 mutations affect chemosensory function and dauer formation.
        The annotation suggests OSM-3 promotes dauer development (PMID:7828815).
      action: KEEP_AS_NON_CORE
      reason: Dauer phenotype is secondary to ciliary defects. OSM-3 mutants 
        have defective sensory cilia which impairs pheromone sensing required 
        for dauer decision. This is not a core function but a downstream 
        consequence.
      supported_by:
        - reference_id: PMID:7828815
          supporting_text: Multiple chemosensory defects in daf-11 and daf-21 
            mutants of Caenorhabditis elegans.
  - term:
      id: GO:0043053
      label: dauer entry
    evidence_type: IGI
    original_reference_id: PMID:1732156
    review:
      summary: Genetic analysis shows osm-3 affects dauer entry through 
        chemosensory defects (PMID:1732156).
      action: KEEP_AS_NON_CORE
      reason: Dauer phenotype is secondary to ciliary defects. OSM-3's role in 
        dauer is indirect through its effects on sensory cilia function.
      supported_by:
        - reference_id: PMID:1732156
          supporting_text: Dauer-defective mutations in nine genes cause 
            structurally defective chemosensory cilia, thereby blocking 
            chemosensation
  - term:
      id: GO:0060271
      label: cilium assembly
    evidence_type: IGI
    original_reference_id: PMID:1732156
    review:
      summary: Genetic analysis places osm-3 among genes required for proper 
        cilium structure (PMID:1732156).
      action: ACCEPT
      reason: Core biological function of OSM-3 - required for distal segment 
        assembly.
      supported_by:
        - reference_id: PMID:1732156
          supporting_text: Dauer-defective mutations in nine genes cause 
            structurally defective chemosensory cilia
  - term:
      id: GO:0097730
      label: non-motile cilium
    evidence_type: IDA
    original_reference_id: PMID:22342749
    review:
      summary: OSM-3 localization in sensory cilia shown by fluorescence 
        microscopy in endocytosis study (PMID:22342749).
      action: ACCEPT
      reason: Direct localization data supporting ciliary localization.
      supported_by:
        - reference_id: PMID:22342749
          supporting_text: Feb 16. Endocytosis genes facilitate protein and 
            membrane transport in C.
  - term:
      id: GO:0036064
      label: ciliary basal body
    evidence_type: IDA
    original_reference_id: PMID:22922713
    review:
      summary: OSM-3 localizes to the basal body region in the context of 
        BBSome-IFT assembly studies (PMID:22922713).
      action: ACCEPT
      reason: Direct experimental evidence from comprehensive IFT study.
      supported_by:
        - reference_id: PMID:22922713
          supporting_text: the BBSome (refs 3, 4), a group of conserved proteins
            affected in human Bardet-Biedl syndrome(5) (BBS), assembles IFT 
            complexes at the ciliary base, then binds to the anterograde IFT 
            particle in a DYF-2- (an orthologue of human WDR19) and 
            BBS-1-dependent manner, and lastly reaches the ciliary tip to 
            regulate proper IFT recycling
  - term:
      id: GO:0097730
      label: non-motile cilium
    evidence_type: IDA
    original_reference_id: PMID:9950681
    review:
      summary: First demonstration of OSM-3 localization in sensory cilia using 
        GFP reporters and immunolocalization (PMID:9950681).
      action: ACCEPT
      reason: Seminal paper establishing OSM-3 ciliary localization.
      supported_by:
        - reference_id: PMID:9950681
          supporting_text: an intense concentration of CeKinesin-II and CeOsm-3 
            polypeptides in the ciliated endings of these chemosensory neurons
  - term:
      id: GO:0008574
      label: plus-end-directed microtubule motor activity
    evidence_type: IDA
    original_reference_id: PMID:17000874
    review:
      summary: Single-molecule assays directly demonstrate OSM-3 is a plus-end 
        directed motor (PMID:17000874).
      action: ACCEPT
      reason: Core molecular function with direct biochemical evidence.
      supported_by:
        - reference_id: PMID:17000874
          supporting_text: OSM-3 was an active plus end-directed motor in a 
            microtubule gliding assay
  - term:
      id: GO:0003777
      label: microtubule motor activity
    evidence_type: IDA
    original_reference_id: PMID:17000880
    review:
      summary: Live imaging demonstrates OSM-3 motor activity in IFT transport 
        at measured velocities (PMID:17000880).
      action: ACCEPT
      reason: Core molecular function with direct in vivo evidence.
      supported_by:
        - reference_id: PMID:17000880
          supporting_text: The assembly and function of cilia on Caenorhabditis 
            elegans neurons depends on the action of two kinesin-2 motors, 
            heterotrimeric kinesin-II and homodimeric OSM-3-kinesin, which 
            cooperate to move the same intraflagellar transport (IFT) particles 
            along microtubule (MT) doublets
  - term:
      id: GO:0005871
      label: kinesin complex
    evidence_type: IDA
    original_reference_id: PMID:17000880
    review:
      summary: OSM-3 forms homodimeric kinesin complexes as demonstrated by 
        biochemical and imaging studies (PMID:17000880).
      action: ACCEPT
      reason: Direct experimental evidence for kinesin complex formation.
      supported_by:
        - reference_id: PMID:17000880
          supporting_text: heterotrimeric kinesin-II and homodimeric 
            OSM-3-kinesin, which cooperate to move the same intraflagellar 
            transport (IFT) particles along microtubule (MT) doublets
  - term:
      id: GO:0043025
      label: neuronal cell body
    evidence_type: IDA
    original_reference_id: PMID:9950681
    review:
      summary: OSM-3 localizes to the cell bodies of chemosensory neurons as 
        shown by immunolocalization and GFP reporters (PMID:9950681).
      action: ACCEPT
      reason: Direct localization data in neuronal cell bodies.
      supported_by:
        - reference_id: PMID:9950681
          supporting_text: a punctate localization pattern in the corresponding 
            cell bodies
  - term:
      id: GO:0048471
      label: perinuclear region of cytoplasm
    evidence_type: IDA
    original_reference_id: PMID:9950681
    review:
      summary: OSM-3 shows punctate localization in the perinuclear region of 
        chemosensory neuron cell bodies (PMID:9950681).
      action: ACCEPT
      reason: Detailed localization consistent with autoinhibited motor waiting 
        to be recruited to IFT.
      supported_by:
        - reference_id: PMID:9950681
          supporting_text: a punctate localization pattern in the corresponding 
            cell bodies
  - term:
      id: GO:0046626
      label: regulation of insulin receptor signaling pathway
    evidence_type: IGI
    original_reference_id: PMID:11381260
    review:
      summary: This annotation is based on genetic interactions affecting DAF-16
        regulation and lifespan. The study shows sensory neurons affect DAF-16 
        localization and aging, but OSM-3's role is indirect through ciliary 
        function (PMID:11381260).
      action: MARK_AS_OVER_ANNOTATED
      reason: The connection to insulin signaling is indirect. OSM-3 mutations 
        cause ciliary defects that affect sensory neuron function. Sensory 
        neurons in turn regulate insulin signaling. OSM-3 does not directly 
        regulate insulin receptor signaling; it enables proper ciliary function 
        in sensory neurons.
      additional_reference_ids:
        - PMID:11381260
      supported_by:
        - reference_id: PMID:11381260
          supporting_text: Regulation of the Caenorhabditis elegans longevity 
            protein DAF-16 by insulin/IGF-1 and germline signaling.
references:
  - id: GO_REF:0000002
    title: Gene Ontology annotation through association of InterPro records with
      GO terms
    findings: []
  - id: GO_REF:0000033
    title: Annotation inferences using phylogenetic trees
    findings: []
  - id: GO_REF:0000043
    title: Gene Ontology annotation based on UniProtKB/Swiss-Prot keyword 
      mapping
    findings: []
  - id: GO_REF:0000044
    title: Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular 
      Location vocabulary mapping, accompanied by conservative changes to GO 
      terms applied by UniProt
    findings: []
  - id: GO_REF:0000108
    title: Automatic assignment of GO terms using logical inference, based on on
      inter-ontology links
    findings: []
  - id: GO_REF:0000117
    title: Electronic Gene Ontology annotations created by ARBA machine learning
      models
    findings: []
  - id: GO_REF:0000120
    title: Combined Automated Annotation using Multiple IEA Methods
    findings: []
  - id: PMID:11381260
    title: Regulation of the Caenorhabditis elegans longevity protein DAF-16 by 
      insulin/IGF-1 and germline signaling.
    findings: []
  - id: PMID:17000874
    title: Autoinhibition regulates the motility of the C. elegans 
      intraflagellar transport motor OSM-3.
    findings:
      - statement: OSM-3 is autoinhibited in compact conformation with low 
          ATPase activity
        supporting_text: displays low microtubule-stimulated adenosine 
          triphosphatase (ATPase) activity
      - statement: OSM-3 is a plus-end directed processive motor when activated
        supporting_text: As expected, OSM-3 was an active plus end-directed 
          motor in a microtubule gliding assay
  - id: PMID:17000880
    title: Mechanism of transport of IFT particles in C. elegans cilia by the 
      concerted action of kinesin-II and OSM-3 motors.
    findings:
      - statement: OSM-3 and kinesin-II cooperate for IFT in middle segment
        supporting_text: heterotrimeric kinesin-II and homodimeric 
          OSM-3-kinesin, which cooperate to move the same intraflagellar 
          transport (IFT) particles along microtubule (MT) doublets
      - statement: OSM-3 forms homodimeric kinesin complexes
        supporting_text: heterotrimeric kinesin-II and homodimeric OSM-3-kinesin
  - id: PMID:1732156
    title: Genetic analysis of chemosensory control of dauer formation in 
      Caenorhabditis elegans.
    findings:
      - statement: osm-3 mutations cause structurally defective chemosensory 
          cilia
        supporting_text: Dauer-defective mutations in nine genes cause 
          structurally defective chemosensory cilia, thereby blocking 
          chemosensation
  - id: PMID:17420466
    title: Mutation of the MAP kinase DYF-5 affects docking and undocking of 
      kinesin-2 motors and reduces their speed in the cilia of Caenorhabditis 
      elegans.
    findings:
      - statement: OSM-3 functions with kinesin-II in middle segment IFT
        supporting_text: anterograde intraflagellar transport (IFT) is mediated 
          by two kinesin-2 complexes, kinesin II and OSM-3 kinesin
      - statement: OSM-3 alone mediates distal segment IFT
        supporting_text: OSM-3 alone mediates transport in the distal segments
  - id: PMID:22342749
    title: Endocytosis genes facilitate protein and membrane transport in C. 
      elegans sensory cilia.
    findings: []
  - id: PMID:22922713
    title: The BBSome controls IFT assembly and turnaround in cilia.
    findings: []
  - id: PMID:26863025
    title: A Screen for Modifiers of Cilia Phenotypes Reveals Novel MKS Alleles 
      and Uncovers a Specific Genetic Interaction between osm-3 and nphp-4.
    findings: []
  - id: PMID:27623382
    title: A Conserved Role for Girdin in Basal Body Positioning and 
      Ciliogenesis.
    findings: []
  - id: PMID:7828815
    title: Multiple chemosensory defects in daf-11 and daf-21 mutants of 
      Caenorhabditis elegans.
    findings: []
  - id: PMID:9950681
    title: Two heteromeric kinesin complexes in chemosensory neurons and sensory
      cilia of Caenorhabditis elegans.
    findings:
      - statement: OSM-3 forms homodimeric kinesin complexes (CeOsm-3)
        supporting_text: heterotrimeric CeKinesin-II and dimeric CeOsm-3
      - statement: OSM-3 localizes to amphid, inner labial, and phasmid neurons
        supporting_text: both CeKinesin-II and CeOsm-3 are expressed in amphid, 
          inner labial, and phasmid chemosensory neurons
  - id: file:worm/osm-3/osm-3-deep-research-falcon.md
    title: Deep research report on osm-3
    findings: []
core_functions:
  - molecular_function:
      id: GO:0008574
      label: plus-end-directed microtubule motor activity
    description: OSM-3 is a homodimeric kinesin-2 motor that moves processively 
      toward microtubule plus-ends at approximately 1.3 um/s in vivo. It 
      cooperates with heterotrimeric kinesin-II in the middle segment (doublet 
      MTs) and functions alone in the distal segment (singlet MTs) of sensory 
      cilia.
    directly_involved_in:
      - id: GO:0035720
        label: intraciliary anterograde transport
      - id: GO:0060271
        label: cilium assembly
    locations:
      - id: GO:0097730
        label: non-motile cilium
      - id: GO:0036064
        label: ciliary basal body
      - id: GO:0005930
        label: axoneme
  - molecular_function:
      id: GO:0016887
      label: ATP hydrolysis activity
    description: OSM-3 hydrolyzes ATP to power its motor activity with a basal 
      rate of approximately 4 ATP/s/head that increases dramatically (to 
      approximately 70-75 ATP/s/head) when autoinhibition is relieved by cargo 
      binding or hinge mutations. This autoinhibitory mechanism is essential for
      proper OSM-3 function in vivo.
suggested_questions:
  - question: What is the structural basis for OSM-3 autoinhibition and how does
      cargo binding relieve it? The G444E mutation in the hinge region activates
      OSM-3, suggesting specific conformational regulation that could be 
      elucidated structurally.
  - question: How is OSM-3 specifically recruited to IFT particles and what role
      does phosphorylation at S316 play? The S316F mutation has NPHP-4 dependent
      effects, suggesting complex regulation of OSM-3 recruitment to IFT 
      machinery.
tags:
  - caeel-ciliopathy

osm-3

Gene Description

Existing Annotations Review

Core Functions

OSM-3 is a homodimeric kinesin-2 motor that moves processively toward microtubule plus-ends at approximately 1.3 um/s in vivo. It cooperates with heterotrimeric kinesin-II in the middle segment (doublet MTs) and functions alone in the distal segment (singlet MTs) of sensory cilia.

References

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Gene Research for Functional Annotation

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