jar

Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0005737 cytoplasm	IBA GO_REF:0000033	ACCEPT	Summary: IBA annotation for cytoplasmic localization. Directly supported by multiple IDA experiments in Drosophila showing jar localizes to the peripheral cytoplasm in punctate patterns in embryos. Reason: Consistent with experimental data from multiple studies. jar was detected in the cytoplasm by immunolocalization in embryos (PMID:1429838), syncytial blastoderm (PMID:7790355), and other tissues (PMID:10523504, PMID:12586070). Supporting Evidence: PMID:7790355 The 95F myosin, a class VI unconventional myosin, associates with particles in the cytoplasm of the Drosophila syncytial blastoderm
GO:0000146 microfilament motor activity	IBA GO_REF:0000033	ACCEPT	Summary: IBA annotation for microfilament motor activity. jar is a class VI unconventional myosin that catalyzes actin-based ATP-dependent particle translocation. The BioReason deep research correctly identifies this activity from the domain architecture. Reason: Directly supported by experimental evidence that jar catalyzes actin-based, ATP-dependent transport of cytoplasmic particles in living embryos (PMID:8202156). The motor domain contains conserved ATP-binding and actin-binding motifs (PMID:1429838). Supporting Evidence: PMID:8202156 this transport is actin-based, ATP-dependent and catalysed by one such unconventional myosin, the 95F myosin file:DROME/jar/jar-deep-research-bioreason-sft.md An actin-based, minus-end-directed motor that uses an ATP-hydrolyzing head and a calmodulin-regulated lever arm to generate force on actin filaments file:DROME/jar/jar-deep-research-falcon.md As a myosin, jar/myosin VI is an ATP-dependent actin motor: it uses ATP hydrolysis to generate force and movement along actin filaments.
GO:0006897 endocytosis	IBA GO_REF:0000033	ACCEPT	Summary: IBA annotation for endocytosis based on phylogenetic inference from vertebrate myosin VI roles in endocytosis. In Drosophila, jar associates with D-CLIP-190, which is a homolog of CLIP-170, a protein that links endocytic vesicles to microtubules. Reason: Supported by the association with D-CLIP-190 (endocytic vesicle-microtubule linker) and localization to endocytic vesicles (PMID:9472041). The vertebrate ortholog MYO6 has well-established endocytic functions. Supporting Evidence: PMID:9472041 it is the first homologue identified of cytoplasmic linker protein (CLIP)-170, a protein that links endocytic vesicles to microtubules
GO:0015629 actin cytoskeleton	IBA GO_REF:0000033	ACCEPT	Summary: IBA annotation for actin cytoskeleton localization. jar is an actin-based motor and associates with actin structures throughout development. Reason: Extensively supported. jar binds actin filaments directly (PMID:16571671 IDA), localizes to actin-rich structures including actin caps and furrows (PMID:7790355), actin cones during spermatid individualization (PMID:10588662), and cortical actin (PMID:12586070). Supporting Evidence: PMID:16571671 myosin VI binds to the cone front using its motor domain
GO:0051015 actin filament binding	IBA GO_REF:0000033	ACCEPT	Summary: IBA annotation for actin filament binding. Redundant with IDA evidence from PMID:16571671. Reason: Directly supported by IDA evidence showing jar binds actin filaments in spermatid actin cones using its motor domain (PMID:16571671). Supporting Evidence: PMID:16571671 myosin VI binds to the cone front using its motor domain
GO:0005886 plasma membrane	IBA GO_REF:0000033	ACCEPT	Summary: IBA annotation for plasma membrane localization. jar is recruited to cortical membrane sites in multiple contexts. Reason: Consistent with jar localization to the cell cortex (PMID:12586070 IDA), membrane furrows in syncytial blastoderm (PMID:7790355), and leading edges of epithelial sheets during dorsal closure (PMID:15454264). Supporting Evidence: PMID:12586070 Miranda localization requires the unconventional myosin VI Jaguar (Jar)
GO:0030048 actin filament-based movement	IBA GO_REF:0000033	ACCEPT	Summary: IBA annotation for actin filament-based movement. jar is a motor that catalyzes actin-based transport. Reason: Directly supported by observations that jar catalyzes actin-based, ATP-dependent cytoplasmic particle transport in living embryos (PMID:8202156). Supporting Evidence: PMID:8202156 Transport of cytoplasmic particles catalysed by an unconventional myosin in living Drosophila embryos
GO:0007015 actin filament organization	IBA GO_REF:0000033	ACCEPT	Summary: IBA annotation for actin filament organization. Supported by experimental evidence that jar is required for proper actin structure formation. Reason: Strongly supported by IMP evidence that jar mutants have defective actin organization during spermatid individualization (PMID:10588662) and syncytial blastoderm (PMID:7790355). jar stabilizes branched actin networks in actin cones (PMID:16571671). Supporting Evidence: PMID:16571671 myosin VI stabilizes a branched actin network in actin structures (cones) that mediate the separation of the syncytial spermatids
GO:0030139 endocytic vesicle	IBA GO_REF:0000033	ACCEPT	Summary: IBA annotation for endocytic vesicle localization. Supported by direct experimental evidence from Drosophila. Reason: jar co-immunoprecipitates with D-CLIP-190, a homolog of the endocytic vesicle-microtubule linker CLIP-170, and both colocalize on vesicle-like particulate structures (PMID:9472041). Supporting Evidence: PMID:9472041 it is the first homologue identified of cytoplasmic linker protein (CLIP)-170, a protein that links endocytic vesicles to microtubules
GO:0003774 cytoskeletal motor activity	IEA GO_REF:0000002	ACCEPT	Summary: IEA annotation from InterPro mapping. jar has a myosin motor domain (IPR001609) with ATPase activity coupled to actin translocation. Reason: Correct mapping. jar is a bona fide actin-activated ATPase motor, directly demonstrated to catalyze particle transport (PMID:8202156).
GO:0005524 ATP binding	IEA GO_REF:0000002	ACCEPT	Summary: IEA annotation from InterPro mapping. jar has a conserved ATP-binding site in the motor domain (residues 151-158 in UniProt). Reason: Correct. The motor domain contains the P-loop NTPase fold with ATP-binding motifs (PMID:1429838). ATP hydrolysis powers the motor activity.
GO:0005737 cytoplasm	IEA GO_REF:0000117	ACCEPT	Summary: IEA annotation from ARBA machine learning. Redundant with multiple IDA and IBA annotations. Reason: Correct and well supported by multiple experimental localizations (PMID:7790355, PMID:10523504, PMID:12586070, PMID:8202156).
GO:0005856 cytoskeleton	IEA GO_REF:0000044	ACCEPT	Summary: IEA annotation from UniProt subcellular location mapping. jar is a cytoskeletal motor protein. Reason: Correct. jar is a cytoskeletal protein that associates with both actin and microtubule cytoskeletons (PMID:9472041).
GO:0015629 actin cytoskeleton	IEA GO_REF:0000117	ACCEPT	Summary: IEA annotation from ARBA. Redundant with IBA annotation for the same term. Reason: Correct. jar is an actin-based motor that localizes to actin cytoskeletal structures.
GO:0016459 myosin complex	IEA GO_REF:0000002	MODIFY	Summary: IEA annotation from InterPro mapping. jar is a myosin heavy chain that forms complexes with light chains. Reason: While not wrong, the more specific term GO:0016461 (unconventional myosin complex) is already annotated with IDA evidence (PMID:9472041). The IEA annotation to the parent term is redundant and less informative. Proposed replacements: unconventional myosin complex
GO:0051015 actin filament binding	IEA GO_REF:0000002	ACCEPT	Summary: IEA annotation from InterPro mapping. Redundant with IDA and IBA annotations. Reason: Correct, well supported by direct experimental evidence (PMID:16571671 IDA).
GO:0070864 sperm individualization complex	IDA PMID:12432073 A role for myosin VI in actin dynamics at sites of membrane ...	ACCEPT	Summary: IDA annotation for localization to sperm individualization complex. jar colocalizes with actin polymerization regulators cortactin and Arp2/3 at the IC. Reason: Directly supported. "myosin VI colocalizes with and is required for the accumulation of the actin polymerization regulatory proteins, cortactin and arp2/3 complex, on actin structures that mediate membrane remodeling during spermatogenesis" (PMID:12432073). Supporting Evidence: PMID:12432073 myosin VI colocalizes with and is required for the accumulation of the actin polymerization regulatory proteins, cortactin and arp2/3 complex, on actin structures that mediate membrane remodeling during spermatogenesis file:DROME/jar/jar-deep-research-falcon.md colocalizes with and is required for accumulation of cortactin and Arp2/3 complex on actin structures mediating membrane remodeling
GO:0070865 investment cone	IDA PMID:16571671 Myosin VI stabilizes an actin network during Drosophila sper...	ACCEPT	Summary: IDA annotation for localization to investment cone. jar binds to the front of actin cones using its motor domain and stabilizes the branched actin network. Reason: Directly demonstrated. "myosin VI binds to the cone front using its motor domain" and "myosin VI stabilizes a branched actin network in actin structures (cones)" (PMID:16571671). Supporting Evidence: PMID:16571671 myosin VI binds to the cone front using its motor domain
GO:0070865 investment cone	IDA PMID:16790438 Androcam is a tissue-specific light chain for myosin VI in t...	ACCEPT	Summary: IDA annotation for investment cone localization. jar and its light chain Androcam precisely colocalize at the leading edge of actin cones. Reason: Directly supported. "Acam and myosin VI precisely colocalize at the leading edge of the actin cones" (PMID:16790438). Supporting Evidence: PMID:16790438 Acam and myosin VI precisely colocalize at the leading edge of the actin cones
GO:0070865 investment cone	IDA PMID:21853045 Myosin VI regulates actin structure specialization through c...	ACCEPT	Summary: IDA annotation for investment cone localization. Domain analysis showed both motor and cargo-binding domains are needed for cone front localization. Reason: Directly demonstrated. "The head (motor) and globular tail (cargo-binding) domains were both needed for localization at the cone front and dense meshwork formation" (PMID:21853045). Supporting Evidence: PMID:21853045 The head (motor) and globular tail (cargo-binding) domains were both needed for localization at the cone front and dense meshwork formation file:DROME/jar/jar-deep-research-falcon.md both the head (motor) domain and the globular tail (cargo-binding) domain are required for myosin VI localization to actin-cone fronts
GO:0007300 ovarian nurse cell to oocyte transport	IDA PMID:9351468 Drosophila unconventional myosin VI is involved in intra- an...	ACCEPT	Summary: IDA annotation based on direct observation of jar involvement in transport of particles from nurse cells into the oocyte via ring canals. Reason: Directly demonstrated using antibody microinjection and time-lapse microscopy. "this unconventional myosin of class VI is involved in the transport processes" (PMID:9351468). Supporting Evidence: PMID:9351468 this unconventional myosin of class VI is involved in the transport processes...Additional myosin-VI molecules located at the rim of the ring canals seem to be involved in particle transport into the oocyte
GO:0007300 ovarian nurse cell to oocyte transport	IMP PMID:9351468 Drosophila unconventional myosin VI is involved in intra- an...	ACCEPT	Summary: IMP annotation based on anti-jar antibody injection blocking transport. Reason: Supported by functional inhibition: antibody injection against jar blocked particle transport from nurse cells to oocyte (PMID:9351468). Supporting Evidence: PMID:9351468 Video-intensified fluorescence timelapse microscopy, in combination with microinjections of antibodies directed against Drosophila 95F myosin, have revealed that this unconventional myosin of class VI is involved in the transport processes
GO:0030426 growth cone	IDA PMID:25694447 Drosophila CLIP-190 and mammalian CLIP-170 display reduced m...	ACCEPT	Summary: IDA annotation for growth cone localization. CLIP-190 forms F-actin-dependent patches in growth cones mediated by binding to myosin VI, and jar is detected in growth cones. Reason: Supported by the finding that CLIP-190 and CLIP-170 form "F-actin-dependent patches in growth cones, mediated by binding of the coiled-coil domain to myosin-VI" (PMID:25694447). Supporting Evidence: PMID:25694447 CLIP-190 and CLIP-170 form F-actin-dependent patches in growth cones, mediated by binding of the coiled-coil domain to myosin-VI
GO:0031476 myosin VI complex	IPI PMID:16917818 Native nonmuscle myosin II stability and light chain binding...	ACCEPT	Summary: IPI annotation based on co-precipitation of jar with the essential light chain (mlc-c). Mass spectrometry identified myosin VI among the binding partners of the essential light chain. Reason: Supported by mass spectrometry and co-precipitation data identifying jar as an essential light chain binding partner (PMID:16917818). Supporting Evidence: PMID:16917818 We identify four myosins (myosin II, myosin V, myosin VI and myosin VIIA)...as binding partners for the essential light chain
GO:0032991 protein-containing complex	IPI PMID:21368190 Proteomics approach to study the functions of Drosophila myo...	KEEP AS NON CORE	Summary: IPI annotation for protein-containing complex based on identification of multiple cargo-binding partners including Cornetto. Reason: The annotation is correct but overly generic. The specific partners identified include Cornetto, a microtubule-associated protein involved in Hedgehog secretion (PMID:21368190). A more specific term would be preferred but this captures the physical interaction data. Supporting Evidence: PMID:21368190 the microtubule-associated protein Cornetto bound myosin VI
GO:0045921 positive regulation of exocytosis	IMP PMID:21368190 Proteomics approach to study the functions of Drosophila myo...	ACCEPT	Summary: IMP annotation for positive regulation of exocytosis based on requirement of jar for Hedgehog secretion. Reason: Supported by the finding that jar and its binding partner Cornetto are both required for secretion of the lipidated morphogen Hedgehog (PMID:21368190). Supporting Evidence: PMID:21368190 we demonstrated a role for both in secretion of the lipidated morphogen Hedgehog
GO:0047497 mitochondrion transport along microtubule	IDA PMID:20592219 Evidence that myosin activity opposes microtubule-based axon...	ACCEPT	Summary: IDA annotation for mitochondrial transport regulation. RNAi depletion of jar selectively increased retrograde mitochondrial transport in neurons, suggesting jar opposes microtubule-based transport to facilitate docking. Reason: Directly demonstrated by RNAi experiments. "Myosin VI depletion increased the same movement parameters but was selective for retrograde movement" (PMID:20592219). While jar opposes rather than promotes this transport, it is still directly involved in regulating the process. Supporting Evidence: PMID:20592219 Myosin VI depletion increased the same movement parameters but was selective for retrograde movement
GO:0008104 intracellular protein localization	IMP PMID:19204120 Protein phosphatase 4 mediates localization of the Miranda c...	ACCEPT	Summary: IMP annotation based on the finding that Miranda localization is affected in jar mutants, and the PP4 phosphatase pathway mediates Miranda complex localization. Reason: Supported by genetic evidence. jar is required for proper basal localization of Miranda and associated cell fate determinants (PMID:12586070). The PP4 pathway acts in parallel or downstream (PMID:19204120). Supporting Evidence: PMID:12586070 Miranda localization requires the unconventional myosin VI Jaguar (Jar)
GO:0005516 calmodulin binding	IPI PMID:16790438 Androcam is a tissue-specific light chain for myosin VI in t...	ACCEPT	Summary: IPI annotation for calmodulin binding. The IQ domain of jar can bind calmodulin, though in the testis, Androcam replaces calmodulin as the light chain. Reason: Supported by in vitro binding data. "Drosophila CaM also shows high affinity interactions with these peptides" referring to the IQ domain peptides (PMID:16790438). Although in the testis Androcam replaces CaM, calmodulin binding is a genuine molecular function. Supporting Evidence: PMID:16790438 although Drosophila CaM also shows high affinity interactions with these peptides, we cannot detect a CaM/myosin VI interaction in the testis
GO:0007015 actin filament organization	IMP PMID:10588662 Class VI unconventional myosin is required for spermatogenes...	ACCEPT	Summary: IMP annotation for actin filament organization based on spermatogenesis mutant phenotype. jar mutants show defective IC movement and actin structure formation. Reason: Directly supported. jar mutations cause defects in individualization complex organization and actin cone formation (PMID:10588662). Supporting Evidence: PMID:10588662 IC movement is aberrant in these 95F myosin mutants, indicating a critical role for 95F myosin in IC movement
GO:0007291 sperm individualization	IMP PMID:10588662 Class VI unconventional myosin is required for spermatogenes...	ACCEPT	Summary: IMP annotation for sperm individualization. jar mutations cause male sterility due to defective spermatid individualization. Reason: Core function. "This reduction of 95F myosin causes male sterility as a result of defects in spermatid individualization" (PMID:10588662). This is one of the best-characterized functions of jar. Supporting Evidence: PMID:10588662 This reduction of 95F myosin causes male sterility as a result of defects in spermatid individualization. Germ line transformation with the 95F myosin heavy chain cDNA rescues the male sterility phenotype
GO:0007291 sperm individualization	IMP PMID:16571671 Myosin VI stabilizes an actin network during Drosophila sper...	ACCEPT	Summary: IMP annotation for sperm individualization. jar stabilizes actin cones required for spermatid separation; mutant cones fail to accumulate F-actin. Reason: Strongly supported. "In a myosin VI mutant, the cones do not accumulate F-actin during cone movement" (PMID:16571671). Supporting Evidence: PMID:16571671 In a myosin VI mutant, the cones do not accumulate F-actin during cone movement, whereas overexpression of myosin VI leads to bigger cones with more F-actin
GO:0030317 flagellated sperm motility	IMP PMID:10588662 Class VI unconventional myosin is required for spermatogenes...	KEEP AS NON CORE	Summary: IMP annotation for flagellated sperm motility. jar mutations cause male sterility because spermatids fail to individualize and thus cannot become motile. Reason: This is an indirect consequence of the individualization defect rather than a direct role in sperm motility. jar is not a flagellar motor -- it is required for the individualization process that is a prerequisite for motile sperm production. Supporting Evidence: PMID:10588662 This reduction of 95F myosin causes male sterility as a result of defects in spermatid individualization
GO:0031476 myosin VI complex	IPI PMID:16790438 Androcam is a tissue-specific light chain for myosin VI in t...	ACCEPT	Summary: IPI annotation for myosin VI complex. jar and Androcam co-immunoprecipitate from testis and interact in yeast two-hybrid assays. Reason: Directly demonstrated. "myosin VI and Acam co-immunoprecipitate from the testis and interact in yeast two-hybrid assays" (PMID:16790438). Supporting Evidence: PMID:16790438 myosin VI and Acam co-immunoprecipitate from the testis and interact in yeast two-hybrid assays
GO:0032970 regulation of actin filament-based process	IGI PMID:12432073 A role for myosin VI in actin dynamics at sites of membrane ...	ACCEPT	Summary: IGI annotation for regulation of actin filament-based process. jar and dynamin (shibire) function in parallel pathways to regulate actin dynamics during spermatogenesis. Reason: Supported by genetic interaction data. "when dynamin and myosin VI function are both impaired, major defects in actin structures are observed" (PMID:12432073). Supporting Evidence: PMID:12432073 when dynamin and myosin VI function are both impaired, major defects in actin structures are observed...myosin VI and dynamin function in parallel pathways that regulate actin dynamics
GO:0032970 regulation of actin filament-based process	IMP PMID:16571671 Myosin VI stabilizes an actin network during Drosophila sper...	ACCEPT	Summary: IMP annotation for regulation of actin filament-based process. jar stabilizes actin networks in actin cones during spermatid individualization. Reason: Directly supported. jar mutant cones fail to accumulate F-actin; overexpression leads to larger cones with more F-actin (PMID:16571671). Supporting Evidence: PMID:16571671 In a myosin VI mutant, the cones do not accumulate F-actin during cone movement, whereas overexpression of myosin VI leads to bigger cones with more F-actin
GO:0051015 actin filament binding	IDA PMID:16571671 Myosin VI stabilizes an actin network during Drosophila sper...	ACCEPT	Summary: IDA annotation for actin filament binding. FRAP experiments showed jar binds actin at cone fronts with slow turnover, consistent with tethering. Reason: Directly demonstrated. "myosin VI binds to the cone front using its motor domain. Fluorescence recovery after photobleach experiments...revealed that myosin VI remains bound to F-actin for minutes" (PMID:16571671). Supporting Evidence: PMID:16571671 myosin VI remains bound to F-actin for minutes, suggesting its role is tethering, rather than transporting cargo file:DROME/jar/jar-deep-research-falcon.md FRAP of GFP-myosin VI indicates myosin VI can remain actin-bound for minutes, suggesting stable binding rather than rapid transport
GO:0070856 myosin VI light chain binding	IPI PMID:16790438 Androcam is a tissue-specific light chain for myosin VI in t...	ACCEPT	Summary: IPI annotation for myosin VI light chain binding. jar binds Androcam (a calmodulin-related protein) as a tissue-specific light chain in the testis. Reason: Directly demonstrated. "Acam binds with high affinity to peptide versions of both myosin VI light chain binding sites" (PMID:16790438). Supporting Evidence: PMID:16790438 Acam binds with high affinity to peptide versions of both myosin VI light chain binding sites
GO:0003779 actin binding	IMP PMID:7790355 The 95F unconventional myosin is required for proper organiz...	ACCEPT	Summary: IMP annotation for actin binding based on the syncytial blastoderm study. Anti-jar antibody injection disrupts actin cytoskeleton organization. Reason: Supported by functional evidence. Antibody inhibition of jar leads to "gross defects in the actin cytoskeleton, including indistinct actin caps and furrows" (PMID:7790355). jar was originally identified as a 140-kD ATP-sensitive actin-binding protein. Supporting Evidence: PMID:7790355 The 95F myosin, a class VI unconventional myosin, associates with particles in the cytoplasm
GO:0005737 cytoplasm	IDA PMID:7790355 The 95F unconventional myosin is required for proper organiz...	ACCEPT	Summary: IDA annotation for cytoplasm localization based on immunolocalization in syncytial blastoderm. Reason: Directly observed. jar associates with cytoplasmic particles in the syncytial blastoderm (PMID:7790355). Supporting Evidence: PMID:7790355 The 95F myosin, a class VI unconventional myosin, associates with particles in the cytoplasm of the Drosophila syncytial blastoderm
GO:0006997 nucleus organization	IMP PMID:7790355 The 95F unconventional myosin is required for proper organiz...	ACCEPT	Summary: IMP annotation for nucleus organization. jar inhibition leads to aberrant nuclear morphology and positioning in the syncytial blastoderm. Reason: Directly supported. "This disorganization is seen as aberrant nuclear morphology and position" (PMID:7790355). Nuclear defects are a consequence of actin cytoskeleton disorganization caused by loss of jar function. Supporting Evidence: PMID:7790355 This disorganization is seen as aberrant nuclear morphology and position and is suggestive of failures in cytoskeletal function
GO:0007051 spindle organization	IMP PMID:7790355 The 95F unconventional myosin is required for proper organiz...	KEEP AS NON CORE	Summary: IMP annotation for spindle organization. Loss of jar function leads to defective pseudocleavage furrows that fail to separate adjacent spindles. Reason: The spindle defects are secondary to the actin furrow defects. "These furrows do not separate adjacent mitoses, since microtubules cross over them. These inappropriate microtubule interactions lead to aberrant nuclear divisions" (PMID:7790355). The primary role of jar here is in furrow formation, not directly in spindle assembly. Supporting Evidence: PMID:7790355 These furrows do not separate adjacent mitoses, since microtubules cross over them. These inappropriate microtubule interactions lead to aberrant nuclear divisions
GO:0030036 actin cytoskeleton organization	IMP PMID:7790355 The 95F unconventional myosin is required for proper organiz...	ACCEPT	Summary: IMP annotation for actin cytoskeleton organization in the syncytial blastoderm. Reason: Directly supported. jar inhibition causes "gross defects in the actin cytoskeleton, including indistinct actin caps and furrows, missing actin structures, abnormal spacing of caps, and abnormally spaced furrows" (PMID:7790355). Supporting Evidence: PMID:7790355 Nuclear defects correlate with gross defects in the actin cytoskeleton, including indistinct actin caps and furrows, missing actin structures, abnormal spacing of caps, and abnormally spaced furrows
GO:0030589 pseudocleavage involved in syncytial blastoderm formation	IMP PMID:7790355 The 95F unconventional myosin is required for proper organiz...	ACCEPT	Summary: IMP annotation for pseudocleavage. jar is required for normal transient membrane furrow formation during the syncytial blastoderm stage. Reason: Core function in early embryogenesis. "95F myosin function is required to generate normal actin-based transient membrane furrows" and "actin furrows do not invaginate as deeply into the embryo as do normal furrows" (PMID:7790355). Supporting Evidence: PMID:7790355 We propose that 95F myosin function is required to generate normal actin-based transient membrane furrows
GO:0051647 nucleus localization	IMP PMID:7790355 The 95F unconventional myosin is required for proper organiz...	KEEP AS NON CORE	Summary: IMP annotation for nucleus localization. jar inhibition causes abnormal nuclear positioning in the syncytial blastoderm. Reason: Nuclear positioning defects are secondary to actin cytoskeleton disorganization. The primary jar function is in actin furrow formation; nuclear mispositioning is a downstream consequence. Supporting Evidence: PMID:7790355 This disorganization is seen as aberrant nuclear morphology and position and is suggestive of failures in cytoskeletal function
GO:0005737 cytoplasm	IDA PMID:10523504 A targeted gene silencing technique shows that Drosophila my...	ACCEPT	Summary: IDA annotation for cytoplasm localization based on antibody staining in follicle cells. Reason: Directly observed. "Antibody staining shows that the expression of myosin 95F is greatly decreased in follicle cells when antisense Mhc95F RNA is expressed" -- implying antibody detection in cytoplasm of follicle cells (PMID:10523504). Supporting Evidence: PMID:10523504 Antibody staining shows that the expression of myosin 95F is greatly decreased in follicle cells when antisense Mhc95F RNA is expressed
GO:0007297 follicle cell of egg chamber migration	IMP PMID:10523504 A targeted gene silencing technique shows that Drosophila my...	ACCEPT	Summary: IMP annotation for follicle cell migration. Antisense knockdown of jar causes aberrant follicle cell migrations during oogenesis. Reason: Directly demonstrated. "abnormal follicle cell shapes and aberrant follicle cell migrations are observed when antisense Mhc95F is expressed in follicle cells" (PMID:10523504). Supporting Evidence: PMID:10523504 abnormal follicle cell shapes and aberrant follicle cell migrations are observed when antisense Mhc95F is expressed in follicle cells during stages 9 to 10
GO:0007552 metamorphosis	IMP PMID:10523504 A targeted gene silencing technique shows that Drosophila my...	KEEP AS NON CORE	Summary: IMP annotation for metamorphosis. Antisense knockdown during development frequently results in lethality; surviving flies have malformed legs and wings. Reason: The metamorphosis defects are pleiotropic consequences of jar loss rather than a specific involvement in the metamorphosis program. jar likely contributes via its general role in epithelial morphogenesis and cell shape maintenance. Supporting Evidence: PMID:10523504 Interfering with expression of Drosophila myosin VI at various developmental stages frequently results in lethality. During metamorphosis it results in adult flies with malformed legs and wings
GO:0007560 imaginal disc morphogenesis	IMP PMID:10523504 A targeted gene silencing technique shows that Drosophila my...	KEEP AS NON CORE	Summary: IMP annotation for imaginal disc morphogenesis. jar knockdown results in malformed appendages, indicating requirement for imaginal disc morphogenesis. Reason: Pleiotropic consequence of jar loss of function. jar is required for imaginal disc morphogenesis likely through its roles in cell shape, adhesion, and membrane dynamics. Supporting Evidence: PMID:10523504 myosin VI is essential for imaginal disc morphogenesis
GO:0008363 larval chitin-based cuticle development	IMP PMID:10523504 A targeted gene silencing technique shows that Drosophila my...	KEEP AS NON CORE	Summary: IMP annotation for larval cuticle development. jar knockdown is lethal and affects larval development. Reason: Likely a pleiotropic consequence of jar loss. jar is a general motor protein required for membrane dynamics and cell morphogenesis; cuticle defects are a secondary phenotype. Supporting Evidence: PMID:10523504 Interfering with expression of Drosophila myosin VI at various developmental stages frequently results in lethality
GO:0016333 morphogenesis of follicular epithelium	IMP PMID:10523504 A targeted gene silencing technique shows that Drosophila my...	ACCEPT	Summary: IMP annotation for follicular epithelium morphogenesis. jar knockdown causes abnormal follicle cell shapes during oogenesis. Reason: Directly supported. jar is expressed in migrating follicle cells and its loss causes aberrant cell shapes and migrations (PMID:10523504). Supporting Evidence: PMID:10523504 the Drosophila myosin VI is required for follicle cell epithelial morphogenesis
GO:0005515 protein binding	IPI PMID:12586070 The Drosophila myosin VI Jaguar is required for basal protei...	MODIFY	Summary: IPI annotation for protein binding based on direct binding of Miranda to jar. Reason: Per curation guidelines, 'protein binding' is uninformative. The specific interaction is Miranda binding, which is relevant to the basal protein targeting function. A more specific term would be appropriate. Proposed replacements: protein phosphorylated amino acid binding Supporting Evidence: PMID:12586070 Miranda directly binds to Jar
GO:0005737 cytoplasm	IDA PMID:12586070 The Drosophila myosin VI Jaguar is required for basal protei...	ACCEPT	Summary: IDA annotation for cytoplasm localization in neuroblasts. Reason: Directly observed in immunolocalization studies of neuroblasts (PMID:12586070). Supporting Evidence: PMID:12586070 Miranda localization requires the unconventional myosin VI Jaguar (Jar)
GO:0005737 cytoplasm	IDA PMID:8202156 Transport of cytoplasmic particles catalysed by an unconvent...	ACCEPT	Summary: IDA annotation for cytoplasm localization based on observation of jar-associated particle transport in living embryos. Reason: Directly observed. jar catalyzes transport of cytoplasmic particles in embryos (PMID:8202156). Supporting Evidence: PMID:8202156 this transport is actin-based, ATP-dependent and catalysed by one such unconventional myosin, the 95F myosin
GO:0005938 cell cortex	IDA PMID:12586070 The Drosophila myosin VI Jaguar is required for basal protei...	ACCEPT	Summary: IDA annotation for cell cortex localization in neuroblasts. jar localizes to the basal cortex where it recruits Miranda. Reason: Directly demonstrated in neuroblasts. jar localizes cortically and is required for basal cortical targeting of Miranda (PMID:12586070). Supporting Evidence: PMID:12586070 Miranda localization requires the unconventional myosin VI Jaguar (Jar). In jar null mutant embryos, Miranda is delocalized
GO:0030048 actin filament-based movement	IDA PMID:8202156 Transport of cytoplasmic particles catalysed by an unconvent...	ACCEPT	Summary: IDA annotation for actin filament-based movement. First direct demonstration of unconventional myosin-catalyzed transport in living cells. Reason: Landmark study. "this transport is actin-based, ATP-dependent and catalysed by one such unconventional myosin, the 95F myosin" (PMID:8202156). Supporting Evidence: PMID:8202156 this transport is actin-based, ATP-dependent and catalysed by one such unconventional myosin, the 95F myosin
GO:0045167 asymmetric protein localization involved in cell fate determination	IMP PMID:12586070 The Drosophila myosin VI Jaguar is required for basal protei...	ACCEPT	Summary: IMP annotation for asymmetric protein localization in neuroblast cell fate determination. jar null mutants have delocalized Miranda. Reason: Directly demonstrated. "In jar null mutant embryos, Miranda is delocalized and the spindle is misoriented" (PMID:12586070). Miranda is a key adaptor for asymmetric segregation of cell fate determinants. Supporting Evidence: PMID:12586070 In jar null mutant embryos, Miranda is delocalized and the spindle is misoriented, but the Inscuteable crescent remains apical
GO:0045172 germline ring canal	IDA PMID:9351468 Drosophila unconventional myosin VI is involved in intra- an...	ACCEPT	Summary: IDA annotation for germline ring canal localization. jar localizes to the rim of ring canals where it mediates particle transport into the oocyte. Reason: Directly observed. "Additional myosin-VI molecules located at the rim of the ring canals seem to be involved in particle transport into the oocyte" (PMID:9351468). Supporting Evidence: PMID:9351468 Additional myosin-VI molecules located at the rim of the ring canals seem to be involved in particle transport into the oocyte
GO:0045175 basal protein localization	IMP PMID:12586070 The Drosophila myosin VI Jaguar is required for basal protei...	ACCEPT	Summary: IMP annotation for basal protein localization. jar is required for basal targeting of Miranda in neuroblasts. Reason: Core finding of the study. "Miranda localization requires the unconventional myosin VI Jaguar" and "Miranda and its associated proteins are translocated basally by this actin-based motor" (PMID:12586070). Supporting Evidence: PMID:12586070 Miranda directly binds to Jar, raising the possibility that Miranda and its associated proteins are translocated basally by this actin-based motor file:DROME/jar/jar-deep-research-falcon.md myosin VI/Jar is required for basal localization of the fate determinant adaptor Miranda and for correct spindle orientation
GO:0045175 basal protein localization	IGI PMID:12586070 The Drosophila myosin VI Jaguar is required for basal protei...	ACCEPT	Summary: IGI annotation for basal protein localization based on genetic interaction with lgl (lethal giant larvae). Reason: Supported by the genetic framework of asymmetric division. jar and lgl pathway components interact in establishing basal determinant localization (PMID:12586070). Supporting Evidence: PMID:12586070 Miranda directly binds to Jar, raising the possibility that Miranda and its associated proteins are translocated basally by this actin-based motor
GO:0045178 basal part of cell	IDA PMID:12586070 The Drosophila myosin VI Jaguar is required for basal protei...	ACCEPT	Summary: IDA annotation for basal part of cell localization. jar is found at the basal cortex of neuroblasts. Reason: Directly observed. jar localizes basally in neuroblasts and recruits Miranda to the basal cortex (PMID:12586070). Supporting Evidence: PMID:12586070 Miranda localization requires the unconventional myosin VI Jaguar (Jar). In jar null mutant embryos, Miranda is delocalized
GO:0055057 neuroblast division	IMP PMID:12586070 The Drosophila myosin VI Jaguar is required for basal protei...	ACCEPT	Summary: IMP annotation for neuroblast division. jar null mutants have misoriented spindles and delocalized Miranda during neuroblast division. Reason: Directly supported. jar is required for proper asymmetric neuroblast division through its role in Miranda targeting and spindle orientation (PMID:12586070). Supporting Evidence: PMID:12586070 In jar null mutant embryos, Miranda is delocalized and the spindle is misoriented
GO:0007291 sperm individualization	IGI PMID:12432073 A role for myosin VI in actin dynamics at sites of membrane ...	ACCEPT	Summary: IGI annotation for sperm individualization based on genetic interaction between jar and dynamin (shibire). Reason: Supported by genetic interaction. "when dynamin and myosin VI function are both impaired, major defects in actin structures are observed" during spermatogenesis (PMID:12432073). Supporting Evidence: PMID:12432073 myosin VI and dynamin function in parallel pathways that regulate actin dynamics
GO:0032880 regulation of protein localization	IMP PMID:12432073 A role for myosin VI in actin dynamics at sites of membrane ...	ACCEPT	Summary: IMP annotation for regulation of protein localization. jar is required for proper localization of cortactin and Arp2/3 to actin structures during spermatogenesis. Reason: Directly supported. "myosin VI colocalizes with and is required for the accumulation of the actin polymerization regulatory proteins, cortactin and arp2/3 complex" (PMID:12432073). Supporting Evidence: PMID:12432073 myosin VI colocalizes with and is required for the accumulation of the actin polymerization regulatory proteins, cortactin and arp2/3 complex
GO:0032956 regulation of actin cytoskeleton organization	IMP PMID:12432073 A role for myosin VI in actin dynamics at sites of membrane ...	ACCEPT	Summary: IMP annotation for regulation of actin cytoskeleton organization during spermatogenesis. Reason: Directly supported. jar regulates actin dynamics at sites of membrane remodeling and is required for proper actin structure formation (PMID:12432073). Supporting Evidence: PMID:12432073 Regions of myosin VI accumulation are proposed as sites where actin assembly is coupled to membrane dynamics
GO:0007291 sperm individualization	IMP PMID:16126191 Drosophila myosin V is required for larval development and s...	ACCEPT	Summary: IMP annotation for sperm individualization from a study primarily about myosin V. Both myosin V and myosin VI contribute to individualization. Reason: Although PMID:16126191 is primarily about myosin V, the study also documents the involvement of myosin VI in spermatid individualization, consistent with the well-established role of jar in this process (PMID:10588662, PMID:16571671). Supporting Evidence: PMID:16126191 MyoV contributes to the formation of the actin-based investment cones
GO:0032027 myosin light chain binding	IPI PMID:16917818 Native nonmuscle myosin II stability and light chain binding...	ACCEPT	Summary: IPI annotation for myosin light chain binding. jar was identified as a binding partner for the essential light chain by mass spectrometry and co-precipitation. Reason: Directly demonstrated. "We identify four myosins (myosin II, myosin V, myosin VI and myosin VIIA)...as binding partners for the essential light chain" (PMID:16917818). Supporting Evidence: PMID:16917818 We identify four myosins (myosin II, myosin V, myosin VI and myosin VIIA)...as binding partners for the essential light chain (but not the regulatory light chain) through mass spectrometry and co-precipitation
GO:0007298 border follicle cell migration	IMP PMID:12134162 Myosin VI is required for E-cadherin-mediated border cell mi...	ACCEPT	Summary: IMP annotation for border cell migration. jar depletion from border cells severely inhibits their migration. Reason: Core finding. "depletion of MyoVI specifically from border cells severely inhibited their migration" (PMID:12134162). jar stabilizes E-cadherin and Armadillo required for migration. Supporting Evidence: PMID:12134162 depletion of MyoVI specifically from border cells severely inhibited their migration...MyoVI is required for border cell migration where it stabilizes E-cadherin and Arm
GO:0007391 dorsal closure	IMP PMID:15454264 Myosin VI plays a role in cell-cell adhesion during epitheli...	ACCEPT	Summary: IMP annotation for dorsal closure. jar localizes to the leading edge of the migrating epithelial sheet and is required for proper dorsal closure. Reason: Directly demonstrated. "Dorsal closure, where there is a ring of Myosin VI at the edge of the migrating epithelial sheet, is often abnormal" in jar mutants (PMID:15454264). Supporting Evidence: PMID:15454264 Dorsal closure, where there is a ring of Myosin VI at the edge of the migrating epithelial sheet, is often abnormal
GO:0040001 establishment of mitotic spindle localization	IMP PMID:12586070 The Drosophila myosin VI Jaguar is required for basal protei...	ACCEPT	Summary: IMP annotation for establishment of mitotic spindle localization. jar null mutants have misoriented spindles in neuroblasts. Reason: Directly supported. "In jar null mutant embryos, Miranda is delocalized and the spindle is misoriented" (PMID:12586070). jar contributes to spindle orientation independently of the Inscuteable apical complex. Supporting Evidence: PMID:12586070 In jar null mutant embryos, Miranda is delocalized and the spindle is misoriented, but the Inscuteable crescent remains apical
GO:0045217 cell-cell junction maintenance	TAS PMID:12620217 Asymmetric cell division: Miranda chauffeured by Jaguar?	KEEP AS NON CORE	Summary: TAS annotation for cell-cell junction maintenance based on a review article about neuroblast asymmetric division and Jaguar's role. Reason: PMID:12620217 is a commentary/review by Tuxworth and Chia, not a primary research article. The junction maintenance function is better supported by PMID:15454264 and PMID:12134162 which show jar is required for cell adhesion and E-cadherin stability. Supporting Evidence: PMID:15454264 Myosin VI is crucial for correct cell morphology and maintenance of adhesive cellular contacts within epithelial cell layers
GO:0030048 actin filament-based movement	NAS PMID:1429838 An unconventional myosin heavy chain gene from Drosophila me...	ACCEPT	Summary: NAS annotation for actin filament-based movement. Based on the original cloning paper which identified jar as a new unconventional myosin. Reason: Reasonable inference from the original characterization as an unconventional myosin with a head domain similar to other myosins and ATP-binding, actin-binding motifs (PMID:1429838). Later confirmed by direct observation (PMID:8202156). Supporting Evidence: PMID:1429838 it represents a new class of unconventional myosin heavy chains...contains ATP-binding, actin-binding and calmodulin/myosin light chain-binding motifs
GO:0003779 actin binding	NAS PMID:1429838 An unconventional myosin heavy chain gene from Drosophila me...	ACCEPT	Summary: NAS annotation for actin binding. Based on original identification as an ATP-sensitive actin-binding protein. Reason: jar was originally identified as "a 140-kD ATP-sensitive actin-binding protein" (PMID:1429838). The actin-binding domain was identified in the head region. Supporting Evidence: PMID:1429838 the molecular analysis of a 140-kD ATP-sensitive actin-binding protein
GO:0003779 actin binding	IDA PMID:9472041 A class VI unconventional myosin is associated with a homolo...	ACCEPT	Summary: IDA annotation for actin binding based on biochemical characterization. Reason: jar is an actin-based motor. Actin binding is a fundamental property confirmed by multiple approaches (PMID:9472041, PMID:1429838). Supporting Evidence: PMID:9472041 a class VI unconventional myosin, the Drosophila 95F unconventional myosin, transports particles along actin filaments
GO:0005515 protein binding	IPI PMID:9472041 A class VI unconventional myosin is associated with a homolo...	MODIFY	Summary: IPI annotation for protein binding based on co-immunoprecipitation with D-CLIP-190. Reason: Per curation guidelines, 'protein binding' is uninformative. The specific interaction is with D-CLIP-190 (CLIP-170 homolog), a microtubule-binding protein. A more specific term describing microtubule-associated protein binding would be preferred. Proposed replacements: microtubule binding Supporting Evidence: PMID:9472041 a 195-kD protein that coimmunoprecipitates with a class VI myosin, Drosophila 95F unconventional myosin
GO:0005875 microtubule associated complex	IDA PMID:9472041 A class VI unconventional myosin is associated with a homolo...	ACCEPT	Summary: IDA annotation for microtubule associated complex. jar co-immunoprecipitates with D-CLIP-190 and both cosediment with microtubules. Reason: Directly demonstrated. jar physically associates with D-CLIP-190, which cosediments with microtubules (PMID:9472041). The complex links actin and microtubule systems. Supporting Evidence: PMID:9472041 Cloning and sequencing of the gene encoding the 195-kD protein reveals that it is the first homologue identified of cytoplasmic linker protein (CLIP)-170
GO:0007391 dorsal closure	IEP PMID:1429838 An unconventional myosin heavy chain gene from Drosophila me...	ACCEPT	Summary: IEP annotation for dorsal closure based on expression pattern. jar is expressed at high levels during mid-embryogenesis when dorsal closure occurs. Reason: Although IEP evidence alone is weak, the direct role of jar in dorsal closure was confirmed by IMP evidence (PMID:15454264) and lethal mutant analysis showing defective dorsal closure (PMID:15454264). The IEP annotation is consistent with the confirmed role. Supporting Evidence: PMID:1429838 transcripts and protein are present throughout the life cycle, with peak expression occurring during mid-embryogenesis and adulthood
GO:0008017 microtubule binding	IDA PMID:9472041 A class VI unconventional myosin is associated with a homolo...	ACCEPT	Summary: IDA annotation for microtubule binding. jar associates with microtubule-associated complexes through its interaction with D-CLIP-190. Reason: Supported by co-immunoprecipitation with D-CLIP-190 which cosediments with microtubules, and colocalization on particulate structures that resemble vesicles (PMID:9472041). Note this is indirect microtubule association via D-CLIP-190 rather than direct microtubule binding by jar itself. Supporting Evidence: PMID:9472041 these two proteins may functionally link the actin and microtubule cytoskeletons
GO:0016461 unconventional myosin complex	NAS PMID:1429838 An unconventional myosin heavy chain gene from Drosophila me...	ACCEPT	Summary: NAS annotation for unconventional myosin complex from the original cloning paper. Reason: jar was identified as a new class of unconventional myosin heavy chains (PMID:1429838), later confirmed as class VI. Supporting Evidence: PMID:1429838 it represents a new class of unconventional myosin heavy chains
GO:0016461 unconventional myosin complex	IDA PMID:9472041 A class VI unconventional myosin is associated with a homolo...	ACCEPT	Summary: IDA annotation for unconventional myosin complex. jar forms a complex with D-CLIP-190 and light chains. Reason: Directly demonstrated by immunoprecipitation. jar is a class VI unconventional myosin that forms multi-protein complexes (PMID:9472041). Supporting Evidence: PMID:9472041 a 195-kD protein that coimmunoprecipitates with a class VI myosin, Drosophila 95F unconventional myosin
GO:0030139 endocytic vesicle	IDA PMID:9472041 A class VI unconventional myosin is associated with a homolo...	ACCEPT	Summary: IDA annotation for endocytic vesicle localization. jar colocalizes with D-CLIP-190 on vesicle-like structures in neurons. Reason: Directly observed. "In the axonal processes of neurons, they are colocalized in the same particulate structures, which resemble vesicles" (PMID:9472041). D-CLIP-190 is a homolog of CLIP-170 which links endocytic vesicles to microtubules. Supporting Evidence: PMID:9472041 In the axonal processes of neurons, they are colocalized in the same particulate structures, which resemble vesicles

Gene Description

Existing Annotations Review

Core Functions

Basal protein targeting and spindle orientation in neuroblasts. jar binds Miranda directly and transports it basally during asymmetric neuroblast division. This is required for proper spindle orientation and asymmetric cell fate determination.

Border cell migration via E-cadherin stabilization. jar is required for E-cadherin-mediated border cell migration during oogenesis by stabilizing E-cadherin and Armadillo at the membrane.

Actin-microtubule coordination via D-CLIP-190 interaction. jar associates with D-CLIP-190 (CLIP-170 homolog) to coordinate actin- and microtubule-based transport, linking endocytic vesicles to both cytoskeletal systems in neurons and at the posterior pole of embryos.

References

Deep Research

Bioreason Pro

Falcon

📚 Additional Documentation

Notes

Bioreason Sft Review

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