Dscam1

Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0005576 extracellular region	IEA GO_REF:0000120	ACCEPT	Summary: Dscam1 has well-documented secreted isoforms that lack the transmembrane domain and are released into the hemolymph. Watson et al., 2005 (PMID:16109846) detected secreted Dscam1 proteins in the hemolymph that function in immune recognition by binding bacteria. The deep research confirms alternative splicing produces soluble ectodomains that accumulate in the extracellular space for pathogen recognition. Reason: Strong experimental evidence supports the presence of secreted Dscam1 isoforms in the extracellular region, particularly in hemolymph where they function as immune recognition molecules binding to bacterial surfaces. Supporting Evidence: PMID:16109846 Secreted protein isoforms of Dscam were detected in the hemolymph file:DROME/Dscam1/Dscam1-deep-research.md See deep research file for comprehensive analysis
GO:0005886 plasma membrane	IEA GO_REF:0000120	ACCEPT	Summary: Dscam1 is a single-pass type I transmembrane protein with extensive experimental evidence for plasma membrane localization. The UniProt record confirms its transmembrane nature, and the deep research describes it as an integral membrane protein on neuronal cell surfaces. Multiple studies demonstrate Dscam1 localization to neuronal plasma membranes where it mediates cell-cell recognition. Reason: Consistent evidence across multiple sources confirms Dscam1 as a transmembrane protein localized to the plasma membrane of neurons, where it functions in homophilic binding and cell recognition. Supporting Evidence: PMID:10892653 immunoglobulin superfamily member file:DROME/Dscam1/Dscam1-deep-research-falcon.md membrane-tethered cell-surface receptor
GO:0007155 cell adhesion	IEA GO_REF:0000043	MODIFY	Summary: While Dscam1 is indeed a cell adhesion molecule by structure, its primary function is actually in homophilic repulsion and self-avoidance rather than adhesion. The protein mediates isoform-specific homophilic binding that leads to repulsion between sister dendrites and axons, not stable adhesion. The term cell adhesion is misleading for a protein whose binding triggers avoidance. Reason: Dscam1 functions primarily in self-recognition leading to repulsion/avoidance rather than adhesion. More specific terms like dendrite self-avoidance (GO:0070593) or homophilic cell adhesion via plasma membrane adhesion molecules (GO:0007156) with repulsive outcome would be more accurate. Proposed replacements: dendrite self-avoidance homophilic cell-cell adhesion Supporting Evidence: file:DROME/Dscam1/Dscam1-deep-research-falcon.md the predominant wiring outcome emphasized in authoritative reviews is homophilic recognition coupled to repulsive signaling, driving separation/spacing of sister branches
GO:0007399 nervous system development	IEA GO_REF:0000043	MODIFY	Summary: This broad term is accurate but too general given the extensive specific evidence for Dscam1 roles in axon guidance, dendrite morphogenesis, mushroom body development, and neuronal self-avoidance. Multiple experimental studies demonstrate specific developmental processes that should be annotated instead. Reason: While correct, this term is overly broad. Experimental evidence supports more specific developmental processes like axon guidance (GO:0007411), dendrite morphogenesis (GO:0048813), and mushroom body development (GO:0016319) which are already annotated with experimental evidence. Proposed replacements: axon guidance dendrite morphogenesis
GO:0016020 membrane	IEA GO_REF:0000043	REMOVE	Summary: This annotation is redundant with the more specific plasma membrane (GO:0005886) annotation. Dscam1 is specifically localized to the plasma membrane, not to intracellular membranes. Reason: Redundant with the more specific and accurate plasma membrane (GO:0005886) annotation. No evidence for localization to other membrane systems.
GO:0030424 axon	IEA GO_REF:0000044	ACCEPT	Summary: Extensive evidence supports Dscam1 localization to axons. The deep research notes Dscam1 is expressed on axon processes during embryonic development. Alternative splicing produces isoforms with transmembrane domains that preferentially localize to axons. IDA evidence from PMID:17482551 and PMID:19211897 directly demonstrates axonal localization. Reason: Strong experimental evidence confirms Dscam1 localization to axons where it functions in axon guidance, branching, and fasciculation. Supporting Evidence: PMID:10892653 Dscam also is required for the formation of axon pathways file:DROME/Dscam1/Dscam1-deep-research-falcon.md Dscam is reported as highly expressed in developing mushroom body axons, and these neurons express different arrays of Dscam isoforms
GO:0030425 dendrite	IEA GO_REF:0000044	ACCEPT	Summary: Strong experimental evidence supports dendritic localization. Alternative splicing produces isoforms that preferentially target to dendrites. Matthews et al., 2007 (PMID:17482551) directly demonstrated Dscam1 on dendrites where it mediates self-avoidance. The IDA annotation from PMID:17482551 provides direct experimental support. Reason: Abundant experimental evidence confirms Dscam1 localization to dendrites where it mediates dendrite self-avoidance and prevents inappropriate self-crossing. Supporting Evidence: PMID:17482551 interactions between identical Dscam isoforms on the cell surface underlie self-recognition, while the cytoplasmic tail converts this recognition to dendrite repulsion
GO:0042802 identical protein binding	IEA GO_REF:0000117	ACCEPT	Summary: This is a core molecular function of Dscam1, extensively validated experimentally. Wojtowicz et al., 2004 demonstrated isoform-specific homophilic binding where each isoform binds only to itself. Structural studies by Sawaya et al., 2008 (PMID:18805093) revealed the molecular basis - a symmetric homodimer interface. The IPI annotation from PMID:18805093 provides direct experimental validation. Reason: Isoform-specific homophilic binding is the defining molecular feature of Dscam1, with extensive structural and functional validation showing each isoform binds exclusively to itself. Supporting Evidence: PMID:18805093 Dscam(1-8) forms a symmetric homodimer of S-shaped molecules PMID:15339666 [different Dscam isoforms] exhibit isoform-specific homophilic binding file:DROME/Dscam1/Dscam1-deep-research-falcon.md Dscam1 isoforms display exquisite isoform-specific homophilic binding: a given ectodomain isoform binds strongly to itself but weakly or not at all to nonmatching isoforms, and binding specificity is determined by the sequences in the three variable Ig domains
GO:0042995 cell projection	IEA GO_REF:0000043	REMOVE	Summary: This term is redundant with more specific annotations for axon (GO:0030424) and dendrite (GO:0030425) which are types of cell projections. The specific neuronal projection terms are more informative. Reason: Redundant parent term. Dscam1 is specifically localized to axons and dendrites which are already annotated with experimental evidence.
GO:0043005 neuron projection	IEA GO_REF:0000044	ACCEPT	Summary: This term is accurate but less specific than the axon and dendrite annotations. The IDA evidence from PMID:19211897 supports this localization. However, the more specific child terms (axon, dendrite) with experimental evidence are more informative. Reason: Experimentally validated localization to neuron projections, though the specific axon and dendrite annotations are more informative. Supporting Evidence: PMID:19211897 Endodomain diversity in the Drosophila Dscam and its roles in neuronal morphogenesis
GO:0043204 perikaryon	IEA GO_REF:0000044	ACCEPT	Summary: The perikaryon (neuronal cell body minus nucleus) localization is supported by IDA evidence from PMID:17482551 and PMID:19211897 showing Dscam1 on the neuronal cell body. The annotation for neuronal cell body (GO:0043025) with experimental evidence makes this somewhat redundant. Reason: Experimental evidence supports cell body localization, though the neuronal cell body annotation is more commonly used and has direct experimental support. Supporting Evidence: PMID:17482551 Dendrite self-avoidance is controlled by Dscam
GO:0048812 neuron projection morphogenesis	IEA GO_REF:0000117	ACCEPT	Summary: This broad term encompasses the specific morphogenetic processes that Dscam1 regulates - axon guidance, branching, and dendrite morphogenesis. Experimental evidence strongly supports roles in shaping neuron projections through self-avoidance and guidance mechanisms. Reason: Well-supported by experimental evidence showing Dscam1 is essential for proper morphogenesis of both axons and dendrites through self-recognition and avoidance mechanisms. Supporting Evidence: PMID:17482551 dendrite self-avoidance in Drosophila da sensory neurons requires [Dscam]
GO:0042802 identical protein binding	IPI PMID:18805093 A double S shape provides the structural basis for the extra...	ACCEPT	Summary: Sawaya et al., 2008 solved the crystal structure showing Dscam1 forms symmetric homodimers through matching of variable Ig domains. This is the definitive molecular function - isoform-specific homophilic binding where each of the 38,016 potential isoforms binds exclusively to itself. This is a core, experimentally validated function. Reason: Direct structural evidence demonstrates homophilic binding through a symmetric dimer interface. This isoform-specific self-binding is the molecular basis for self-recognition and is absolutely central to Dscam1 function. Supporting Evidence: PMID:18805093 structure of the homophilic binding region of Dscam, comprising the eight N-terminal Ig domains (Dscam(1-8)). Dscam(1-8) forms a symmetric homodimer of S-shaped molecules
GO:0048814 regulation of dendrite morphogenesis	IGI PMID:25653356 Linking cell surface receptors to microtubules: tubulin fold...	ACCEPT	Summary: The 2015 paper by Okumura et al. showed that tubulin folding cofactor D mediates Dscam1 functions in dendrite morphogenesis. Multiple other studies (PMID:17581959, PMID:16474389, PMID:17482551) provide strong evidence that Dscam1 regulates dendrite morphogenesis through self-avoidance mechanisms. This is a core function. Reason: Extensive experimental evidence demonstrates Dscam1 is essential for proper dendrite morphogenesis, primarily through mediating self-avoidance to prevent sister dendrites from forming fascicles. Supporting Evidence: PMID:25653356 tubulin folding cofactor D mediates Dscam functions during neuronal morphogenesis PMID:17482551 Dendrite self-avoidance is controlled by Dscam
GO:0007411 axon guidance	IGI PMID:23666178 Overexpression of Down syndrome cell adhesion molecule impai...	ACCEPT	Summary: Dscam1 was originally identified as an axon guidance receptor (Schmucker et al., 2000). Multiple studies with IMP evidence (PMID:10892653, PMID:15339666, PMID:18948420) demonstrate its essential role in guiding axons to proper targets. The receptor activity and Dock/Pak signaling pathway are well-characterized. This is a core function. Reason: Axon guidance is one of the primary functions of Dscam1, with extensive experimental validation showing it acts as a guidance receptor directing axon pathfinding through homophilic recognition and Dock/Pak signaling. Supporting Evidence: PMID:10892653 Drosophila Dscam is an axon guidance receptor exhibiting extraordinary molecular diversity PMID:18948420 Dscam guides embryonic axons by Netrin-dependent and -independent functions PMID:23666178 Overexpression of Down syndrome cell adhesion molecule impairs precise synaptic targeting. file:DROME/Dscam1/Dscam1-deep-research-falcon.md Netrin guidance: Dscam/DSCAM is discussed as functioning as a netrin receptor collaborating with DCC
GO:0050976 detection of mechanical stimulus involved in sensory perception of touch	IGI PMID:23666178 Overexpression of Down syndrome cell adhesion molecule impai...	REMOVE	Summary: The 2013 paper by Kim et al. on Dscam overexpression affecting synaptic targeting does not appear to directly demonstrate a role in mechanosensation or touch perception. While Dscam1 is expressed in sensory neurons, its primary characterized function there is dendrite self-avoidance, not sensory transduction. Reason: No clear evidence that Dscam1 is directly involved in mechanosensory transduction. Its role in sensory neurons is primarily structural (dendrite organization) rather than in sensory signal detection. The cited paper focuses on synaptic targeting, not mechanosensation. Supporting Evidence: PMID:23666178 Overexpression of Down syndrome cell adhesion molecule impairs precise synaptic targeting.
GO:0007419 ventral cord development	IGI PMID:19211897 Endodomain diversity in the Drosophila Dscam and its roles i...	KEEP AS NON CORE	Summary: The 2009 paper by Yu et al. on endodomain diversity shows Dscam1 is required for proper CNS development including the ventral nerve cord. Loss-of-function mutants show disorganized axon tracts in the ventral cord. However, this is a consequence of the more specific function in axon guidance rather than a direct role in ventral cord development per se. Reason: While Dscam1 mutants do show ventral cord defects, this is secondary to its primary role in axon guidance. The defects in ventral cord organization result from misguidance of axons rather than a specific developmental role. Supporting Evidence: PMID:19211897 Dscam+19 plays a more important role in the wiring of embryonic neural tracts
GO:0016319 mushroom body development	IMP PMID:19211897 Endodomain diversity in the Drosophila Dscam and its roles i...	ACCEPT	Summary: Multiple studies with IMP evidence demonstrate Dscam1 is essential for mushroom body development. It regulates axon bifurcation and branch segregation in mushroom body neurons. Different isoforms have distinct functions in dorsal vs medial lobe formation. This is a well-characterized developmental role with strong experimental support from multiple labs. Reason: Extensive experimental evidence shows Dscam1 is required for proper mushroom body morphogenesis, particularly for axon bifurcation and the segregation of sister branches into distinct lobes. Supporting Evidence: PMID:19211897 Transgenic Dscam−19 not only effectively prevents multiple self-branches from extending into the same MB lobe in Dscam mutant single-cell MARCM clones, but it also blocks axon bifurcation PMID:11856530 Dscam is required for divergent segregation of sister branches and suppresses ectopic bifurcation of axons
GO:0043005 neuron projection	IDA PMID:19211897 Endodomain diversity in the Drosophila Dscam and its roles i...	ACCEPT	Summary: Direct immunostaining evidence shows Dscam1 localization on neuron projections including both axons and dendrites. This cellular component annotation is well-supported, though the more specific axon and dendrite annotations provide greater detail. Reason: Direct experimental observation confirms Dscam1 presence on neuron projections. This parent term encompasses the specific axon and dendrite localizations. Supporting Evidence: PMID:19211897 Postembryonic neuronal morphogenesis uses Dscam variants lacking exons 19 and 23
GO:0043025 neuronal cell body	IDA PMID:19211897 Endodomain diversity in the Drosophila Dscam and its roles i...	ACCEPT	Summary: Direct immunostaining shows Dscam1 on the neuronal cell body surface in addition to processes. This is consistent with its role as a cell surface receptor that can mediate recognition along the entire neuron surface. Reason: Direct experimental evidence confirms Dscam1 localization to the neuronal cell body plasma membrane where it can participate in cell-cell recognition. Supporting Evidence: PMID:19211897 Skipping exon 19 prevents accumulation of Dscams in neuronal cell bodies PMID:17482551 Dendrite self-avoidance is controlled by Dscam
GO:0016319 mushroom body development	IMP PMID:17581959 Specific Drosophila Dscam juxtamembrane variants control den...	ACCEPT	Summary: Shi et al., 2007 demonstrated that specific Dscam1 juxtamembrane variants control mushroom body development. This is one of multiple studies providing IMP evidence for this function. The annotation is valid and represents a core developmental role. Reason: Strong experimental evidence from multiple independent studies confirms Dscam1 is essential for mushroom body development, with different isoforms having distinct roles. Supporting Evidence: PMID:17581959 specific Drosophila Dscam juxtamembrane variants control dendritic elaboration and axonal arborization
GO:0016319 mushroom body development	IMP PMID:19794492 Robust discrimination between self and non-self neurites req...	ACCEPT	Summary: Hattori et al., 2009 showed that thousands of Dscam1 isoforms are required for proper mushroom body development and self-recognition. This is another independent confirmation of this core function. Reason: Multiple independent studies confirm this essential role. The diversity of Dscam1 isoforms is particularly important for mushroom body neuron wiring. Supporting Evidence: PMID:19794492 Robust discrimination between self and non-self neurites requires thousands of Dscam1 isoforms
GO:0048814 regulation of dendrite morphogenesis	IMP PMID:17581959 Specific Drosophila Dscam juxtamembrane variants control den...	ACCEPT	Summary: Shi et al., 2007 showed specific Dscam1 juxtamembrane variants control dendritic elaboration. This is a core function with multiple lines of experimental support showing Dscam1 regulates dendrite branching and self-avoidance. Reason: Well-validated core function. Dscam1 is essential for proper dendrite morphogenesis through self-avoidance mechanisms that prevent sister dendrites from fasciculating. Supporting Evidence: PMID:17581959 specific Drosophila Dscam juxtamembrane variants control dendritic elaboration and axonal arborization
GO:0050770 regulation of axonogenesis	IMP PMID:17581959 Specific Drosophila Dscam juxtamembrane variants control den...	ACCEPT	Summary: Shi et al., 2007 demonstrated Dscam1 juxtamembrane variants control axonal arborization. Multiple studies show Dscam1 regulates axon branching, bifurcation, and guidance - all aspects of axonogenesis. Reason: Strong experimental evidence supports Dscam1 role in regulating multiple aspects of axon development including branching, guidance, and fasciculation. Supporting Evidence: PMID:17581959 specific Drosophila Dscam juxtamembrane variants control dendritic elaboration and axonal arborization PMID:11856530 Dscam is required for divergent segregation of sister branches and suppresses ectopic bifurcation of axons
GO:0070593 dendrite self-avoidance	IMP PMID:19794492 Robust discrimination between self and non-self neurites req...	ACCEPT	Summary: This is perhaps THE most characteristic function of Dscam1. Hattori et al., 2009 showed thousands of isoforms enable self vs non-self discrimination. Matthews et al., 2007 (PMID:17482551) definitively demonstrated dendrite self-avoidance requires Dscam1. This is a core, defining function. Reason: Dendrite self-avoidance is the paradigmatic function of Dscam1. Isoform-specific homophilic binding enables neurons to distinguish self from non-self, triggering repulsion between sister dendrites. Supporting Evidence: PMID:19794492 Robust discrimination between self and non-self neurites requires thousands of Dscam1 isoforms PMID:17482551 Dendrite self-avoidance is controlled by Dscam file:DROME/Dscam1/Dscam1-deep-research-falcon.md Dendrite self/non-self discrimination required a minimum of approximately ~2,000 isoforms, and this requirement was independent of exon cluster identity
GO:0003823 antigen binding	IDA PMID:16109846 Extensive diversity of Ig-superfamily proteins in the immune...	MARK AS OVER ANNOTATED	Summary: Watson et al., 2005 showed secreted Dscam1 isoforms bind to bacteria in the hemolymph, functioning as pattern recognition molecules in innate immunity. The annotated term GO:0003823 antigen binding is defined for adaptive-immunity interactions (binding of an antigen by an antibody, T-lymphocyte receptor, or MHC complex). Insects have no adaptive immune system, antibodies, or T cells; Dscam1's pathogen binding is an innate pattern-recognition (PRR) activity, so antigen binding is the wrong molecular function term. Reason: GO:0003823 antigen binding is definitionally specific to adaptive immunity (antibody/TCR/MHC-antigen interactions), which is absent in insects. Dscam1 secreted isoforms bind bacterial surfaces as innate-immune hemolymph opsonins, i.e. innate pattern recognition, not antigen binding in the adaptive sense. The more accurate molecular function is GO:0038187 pattern recognition receptor activity (combining with a pathogen-associated molecular pattern to initiate an innate immune response). This remains a non-core, specialized immune function relative to the primary neuronal roles. Proposed replacements: pattern recognition receptor activity Supporting Evidence: PMID:16109846 Secreted protein isoforms of Dscam were detected in the hemolymph, and hemocyte-specific loss of Dscam impaired the efficiency of phagocytic uptake of bacteria, possibly due to reduced bacterial binding
GO:0032490 detection of molecule of bacterial origin	IDA PMID:16109846 Extensive diversity of Ig-superfamily proteins in the immune...	KEEP AS NON CORE	Summary: Watson et al., 2005 demonstrated secreted Dscam1 binds to bacterial surfaces, functioning in pathogen recognition. This immune function is valid but represents a specialized role of secreted isoforms in hemocytes/fat body rather than the primary neuronal function. Reason: Valid but non-core function. Secreted Dscam1 isoforms do detect and bind bacteria in the immune system, but this is secondary to the primary neural development roles. Supporting Evidence: PMID:16109846 Secreted protein isoforms of Dscam were detected in the hemolymph...loss of Dscam impaired the efficiency of phagocytic uptake of bacteria, possibly due to reduced bacterial binding
GO:0048814 regulation of dendrite morphogenesis	IMP PMID:16474389 Dendritic patterning by Dscam and synaptic partner matching ...	ACCEPT	Summary: Zhu et al., 2006 showed Dscam1 mediates dendritic patterning in the antennal lobe. This is another independent confirmation of the core function in dendrite morphogenesis through self-avoidance. Reason: Multiple independent studies confirm this core function. Dscam1-mediated self-avoidance is essential for proper dendrite spacing and morphology. Supporting Evidence: PMID:16474389 Dendritic patterning by Dscam and synaptic partner matching in the Drosophila antennal lobe
GO:0005886 plasma membrane	ISM PMID:17554308 Dscam2 mediates axonal tiling in the Drosophila visual syste...	ACCEPT	Summary: This paper is about Dscam2, not Dscam1. However, the plasma membrane localization of Dscam1 is well-established from other studies. This appears to be a mis-citation but the annotation itself is correct based on other evidence. Reason: While this specific reference is about Dscam2, the plasma membrane localization of Dscam1 is well-supported by other experimental evidence. Supporting Evidence: PMID:17554308 Dscam2 mediates axonal tiling in the Drosophila visual system PMID:10892653 Drosophila Dscam is an axon guidance receptor exhibiting extraordinary molecular diversity. PMID:17482551 Dendrite self-avoidance is controlled by Dscam.
GO:0007411 axon guidance	IMP PMID:18948420 Dscam guides embryonic axons by Netrin-dependent and -indepe...	ACCEPT	Summary: Andrews et al., 2008 showed Dscam1 guides embryonic axons through both Netrin-dependent and independent mechanisms. This is one of many studies confirming the core axon guidance function that led to Dscam1s initial discovery. Reason: Axon guidance is a primary, well-validated function. Dscam1 acts as a guidance receptor directing axon pathfinding through multiple mechanisms. Supporting Evidence: PMID:18948420 Dscam guides embryonic axons by Netrin-dependent and -independent functions
GO:0070593 dendrite self-avoidance	IDA PMID:17482551 Dendrite self-avoidance is controlled by Dscam.	ACCEPT	Summary: Matthews et al., 2007 provided definitive evidence that Dscam1 controls dendrite self-avoidance. They showed isoform-specific homophilic binding triggers repulsion between sister dendrites. This is the paradigmatic Dscam1 function. Reason: This is THE defining function of Dscam1. Direct experimental evidence shows homophilic binding between identical isoforms on sister dendrites triggers repulsion, preventing self-crossing. Supporting Evidence: PMID:17482551 interactions between identical Dscam isoforms on the cell surface underlie self-recognition, while the cytoplasmic tail converts this recognition to dendrite repulsion
GO:0070593 dendrite self-avoidance	IMP PMID:17851526 Dscam diversity is essential for neuronal wiring and self-re...	ACCEPT	Summary: Soba et al., 2007 showed Dscam1 diversity is essential for neuronal wiring and self-recognition. Another key paper establishing dendrite self-avoidance as a core function. Reason: Multiple independent studies confirm dendrite self-avoidance as a central function. The molecular diversity enables self/non-self discrimination. Supporting Evidence: PMID:17851526 Dscam diversity is essential for neuronal wiring and self-recognition
GO:0016319 mushroom body development	IMP PMID:18805093 A double S shape provides the structural basis for the extra...	UNDECIDED	Summary: PMID:18805093 (Sawaya et al., 2008, Cell) is a crystal-structure and biochemical paper reporting the Dscam(1-8) double-S homodimer that explains isoform-specific homophilic binding. It contains no primary mushroom body mutant or phenotypic data of its own (it only cites other labs' wiring studies), so an IMP (mutant phenotype) annotation to mushroom body development cannot be validly supported by this reference. Mushroom body development is genuinely a Dscam1 function, but it is independently supported by other annotations citing appropriate primary IMP papers (e.g. PMID:15339648, PMID:15339649, PMID:17581959, PMID:17851526, PMID:19211897, PMID:19794492). Reason: PMID:18805093 is a structural/biochemical paper lacking the mushroom body mutant-phenotype evidence required for an IMP annotation, so this annotation cannot be validated as cited. The biological process is correct and well-supported elsewhere; this specific evidence-reference pairing should be re-evaluated (re-attributed to a primary IMP paper) by the GOA team. A non-verbatim bracketed paraphrase was removed rather than retained. Supporting Evidence: PMID:18805093 Dscam(1-8) forms a symmetric homodimer of S-shaped molecules
GO:0048846 axon extension involved in axon guidance	IMP PMID:18805093 A double S shape provides the structural basis for the extra...	UNDECIDED	Summary: This annotation is attributed as IMP to PMID:18805093 (Sawaya et al., 2008), which is a crystal-structure and biochemical paper about the double-S homodimer underlying isoform-specific binding. It provides no axon-extension mutant-phenotype data; its content concerns binding specificity, not axon extension. Therefore the IMP evidence cannot be validated against this reference. Dscam1 does plausibly regulate growth cone dynamics and axon extension via Dock/Pak signaling, but that rationale derives from PMID:10892653, not from the structural paper. Reason: PMID:18805093 is a structural/biochemical paper lacking the axon-extension mutant-phenotype evidence required for an IMP annotation, and its only verbatim content here is about binding specificity rather than axon extension. This evidence-reference pairing cannot be validated as cited and should be re-evaluated (re-attributed to a primary IMP paper such as PMID:10892653, which describes Dscam/Dock/Pak control of axon pathfinding) by the GOA team. Supporting Evidence: PMID:18805093 A double S shape provides the structural basis for the extraordinary binding specificity of Dscam isoforms.
GO:0007413 axonal fasciculation	IMP PMID:15339649 Analysis of Dscam diversity in regulating axon guidance in D...	MODIFY	Summary: Zhan et al., 2004 analyzed Dscam1 diversity in regulating axon guidance in mushroom bodies, showing effects on fasciculation. However, Dscam1 primarily mediates de-fasciculation through self-avoidance rather than promoting fasciculation. Reason: Dscam1 actually prevents inappropriate fasciculation through self-avoidance. The term axon defasciculation or regulation of axon fasciculation would be more accurate. Proposed replacements: axonal defasciculation Supporting Evidence: PMID:15339649 Analysis of Dscam diversity in regulating axon guidance in Drosophila mushroom bodies
GO:0016319 mushroom body development	IMP PMID:15339649 Analysis of Dscam diversity in regulating axon guidance in D...	ACCEPT	Summary: Zhan et al., 2004 showed Dscam1 diversity regulates mushroom body axon guidance. Another confirmation of this well-established developmental role. Reason: Consistent evidence from multiple studies confirms Dscam1 is essential for mushroom body development. Supporting Evidence: PMID:15339649 Analysis of Dscam diversity in regulating axon guidance in Drosophila mushroom bodies
GO:0016319 mushroom body development	IMP PMID:17851526 Dscam diversity is essential for neuronal wiring and self-re...	ACCEPT	Summary: Soba et al., 2007 showed Dscam1 diversity is essential for mushroom body wiring. Another independent confirmation of this core developmental function. Reason: Abundant evidence from multiple labs confirms Dscam1 is required for mushroom body development. Supporting Evidence: PMID:17851526 Dscam diversity is essential for neuronal wiring
GO:0021551 central nervous system morphogenesis	IMP PMID:17851526 Dscam diversity is essential for neuronal wiring and self-re...	KEEP AS NON CORE	Summary: While Dscam1 mutants show CNS defects, this broad term is less informative than the specific processes affected - axon guidance, dendrite self-avoidance, and mushroom body development. The more specific annotations better capture Dscam1 functions. Reason: True but overly broad. The specific neural development processes (axon guidance, dendrite morphogenesis) are more informative and better supported. Supporting Evidence: PMID:17851526 Dscam diversity is essential for neuronal wiring
GO:0030424 axon	IDA PMID:17482551 Dendrite self-avoidance is controlled by Dscam.	ACCEPT	Summary: Direct immunostaining evidence shows Dscam1 localization on axons. Matthews et al., 2007 and other studies demonstrate axonal localization where Dscam1 mediates self-avoidance and guidance. Reason: Direct experimental observation confirms axonal localization. Well-supported cellular component annotation. Supporting Evidence: PMID:17482551 Dendrite self-avoidance is controlled by Dscam.
GO:0030425 dendrite	IDA PMID:17482551 Dendrite self-avoidance is controlled by Dscam.	ACCEPT	Summary: Matthews et al., 2007 directly demonstrated Dscam1 on dendrites using immunostaining. This is where Dscam1 mediates self-avoidance to prevent sister dendrite fasciculation. Reason: Direct experimental evidence confirms dendritic localization. Essential for dendrite self-avoidance function. Supporting Evidence: PMID:17482551 Dendrites [with Dscam] distinguish between sister branches
GO:0043025 neuronal cell body	IDA PMID:17482551 Dendrite self-avoidance is controlled by Dscam.	ACCEPT	Summary: Direct immunostaining shows Dscam1 on neuronal cell bodies. Matthews et al., 2007 demonstrated cell body localization along with axons and dendrites. Reason: Direct experimental evidence confirms cell body localization as part of overall neuronal surface expression. Supporting Evidence: PMID:17482551 Dendrite self-avoidance is controlled by Dscam.
GO:0016319 mushroom body development	IMP PMID:15339648 Transmembrane/juxtamembrane domain-dependent Dscam distribut...	ACCEPT	Summary: Wang et al., 2004 showed transmembrane/juxtamembrane domain-dependent Dscam1 distribution affects mushroom body neuronal morphogenesis. Another confirmation of this core function. Reason: Multiple independent studies confirm this essential developmental role. Supporting Evidence: PMID:15339648 Transmembrane/juxtamembrane domain-dependent Dscam distribution and function during mushroom body neuronal morphogenesis
GO:0007411 axon guidance	IMP PMID:15339666 Alternative splicing of Drosophila Dscam generates axon guid...	ACCEPT	Summary: Wojtowicz et al., 2004 showed alternative splicing generates axon guidance receptors with isoform-specific homophilic binding. This seminal paper established the molecular basis for Dscam1s guidance function. Reason: Core function with extensive validation. Dscam1 acts as an axon guidance receptor through isoform-specific recognition. Supporting Evidence: PMID:15339666 Alternative splicing of Drosophila Dscam generates axon guidance receptors that exhibit isoform-specific homophilic binding
GO:0007411 axon guidance	IMP PMID:16678102 The molecular diversity of Dscam is functionally required fo...	ACCEPT	Summary: Chen et al., 2006 showed molecular diversity of Dscam1 is functionally required for neuronal wiring specificity. Another confirmation of the axon guidance role. Reason: Well-established function with evidence from multiple independent studies. Supporting Evidence: PMID:16678102 The molecular diversity of Dscam is functionally required for neuronal wiring specificity in Drosophila
GO:0008046 axon guidance receptor activity	IMP PMID:15339666 Alternative splicing of Drosophila Dscam generates axon guid...	ACCEPT	Summary: Wojtowicz et al., 2004 definitively established Dscam1 as an axon guidance receptor. The protein has all the hallmarks - extracellular recognition domain, transmembrane segment, and cytoplasmic signaling through Dock/Pak. This is a core molecular function. Reason: Dscam1 is a bona fide axon guidance receptor with well-characterized recognition and signaling mechanisms. This molecular function is central to its role. Supporting Evidence: PMID:15339666 Drosophila Dscam generates axon guidance receptors that exhibit isoform-specific homophilic binding PMID:10892653 Drosophila Dscam is an axon guidance receptor file:DROME/Dscam1/Dscam1-deep-research-falcon.md Dscam1 is a neuronal cell-surface recognition molecule whose isoforms share a conserved architecture: 10 Ig domains + 6 fibronectin type III (FNIII) domains extracellularly, a single transmembrane segment, and a C-terminal cytoplasmic tail
GO:0048666 neuron development	IMP PMID:16890528 Drosophila dorsal paired medial neurons provide a general me...	MODIFY	Summary: This paper by Keene et al., 2006 is primarily about dorsal paired medial neurons and memory consolidation, not directly about Dscam1s role in neuron development. While Dscam1 does affect neuron development, this citation seems incorrect for this annotation. Reason: The cited paper does not appear to be primarily about Dscam1. While neuron development is affected by Dscam1, more specific terms like axon guidance and dendrite morphogenesis are better supported. Proposed replacements: axon guidance dendrite morphogenesis Supporting Evidence: PMID:16890528 Drosophila dorsal paired medial neurons provide a general mechanism for memory consolidation. PMID:17482551 Dendrite self-avoidance is controlled by Dscam.
GO:0006909 phagocytosis	IMP PMID:16109846 Extensive diversity of Ig-superfamily proteins in the immune...	KEEP AS NON CORE	Summary: Watson et al., 2005 showed hemocyte-specific loss of Dscam1 impaired phagocytic uptake of bacteria. Secreted Dscam1 acts as an opsonin enhancing bacterial phagocytosis. This immune function is valid but represents a specialized role rather than the primary function. Reason: Valid immune function but not the primary role. The phagocytosis enhancement through bacterial opsonization is a specialized function of secreted isoforms in the immune system. Supporting Evidence: PMID:16109846 hemocyte-specific loss of Dscam impaired the efficiency of phagocytic uptake of bacteria
GO:0007411 axon guidance	IMP PMID:10892653 Drosophila Dscam is an axon guidance receptor exhibiting ext...	ACCEPT	Summary: Schmucker et al., 2000 - the original discovery paper identifying Dscam1 as an axon guidance receptor. They showed Dscam1 mutants have severe axon pathfinding defects and that Dscam1 signals through Dock/Pak. This is a foundational, core function. Reason: This is the original characterization establishing axon guidance as a primary function. Extensive subsequent work has confirmed and expanded on this core role. Supporting Evidence: PMID:10892653 Drosophila Dscam is an axon guidance receptor exhibiting extraordinary molecular diversity
GO:0007411 axon guidance	IGI PMID:10892653 Drosophila Dscam is an axon guidance receptor exhibiting ext...	ACCEPT	Summary: Genetic interaction studies in the original Schmucker et al., 2000 paper showed Dscam1 interacts with Dock and Pak in axon guidance. Well-validated core function. Reason: Genetic evidence complements the IMP evidence establishing axon guidance as a primary function. Supporting Evidence: PMID:10892653 Genetic studies revealed that Dscam, Dock and Pak [act together in axon guidance]
GO:0007411 axon guidance	IMP PMID:11856530 Drosophila Dscam is required for divergent segregation of si...	ACCEPT	Summary: Wang et al., 2002 showed Dscam1 is required for proper segregation of sister axon branches and suppresses ectopic bifurcation. This demonstrates specific aspects of the axon guidance function. Reason: Well-validated function showing Dscam1 guides axon branch segregation and prevents inappropriate branching. Supporting Evidence: PMID:11856530 Drosophila Dscam is required for divergent segregation of sister branches and suppresses ectopic bifurcation of axons
GO:0007422 peripheral nervous system development	IMP PMID:12546818 Axonal targeting of olfactory receptor neurons in Drosophila...	KEEP AS NON CORE	Summary: Hummel et al., 2003 showed Dscam1 controls axonal targeting of olfactory receptor neurons, which are part of the PNS. While valid, this is more specifically about axon guidance in the PNS rather than general PNS development. Reason: True but the more specific function is axon guidance in PNS neurons. The developmental defects are secondary to the guidance function. Supporting Evidence: PMID:12546818 Axonal targeting of olfactory receptor neurons in Drosophila is controlled by Dscam
GO:0098631 cell adhesion mediator activity	IEA	NEW	Summary: cell adhesion mediator activity identified from core_functions analysis Reason: This molecular function term captures Dscam1's role as a cell adhesion molecule that mediates isoform-specific homophilic binding for self-recognition and self-avoidance. Supporting Evidence: PMID:17482551 interactions between identical Dscam isoforms on the cell surface underlie self-recognition, while the cytoplasmic tail converts this recognition to dendrite repulsion PMID:19794492 Robust discrimination between self and non-self neurites requires thousands of Dscam1 isoforms PMID:15339666 Alternative splicing of Drosophila Dscam generates axon guidance receptors that exhibit isoform-specific homophilic binding

Gene Description

Existing Annotations Review

Core Functions

Each of 38,016 potential isoforms binds exclusively to itself through matching of variable Ig domains, enabling molecular self-recognition that underlies neural self-avoidance.

Functions as a guidance receptor directing axon pathfinding through isoform-specific recognition and downstream signaling via the Dock/Pak pathway to regulate cytoskeletal dynamics.

Mediates homophilic cell adhesion through isoform-specific binding, preventing inappropriate adhesion between non-self neurites while enabling self-recognition.

References

Suggested Questions for Experts

Suggested Experiments

Deep Research

Falcon

Deep Research Report: Dscam1 (fly)

📚 Additional Documentation

Notes

Bioreason Rl Predictions

Bioreason Rl Review

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