tgrC1

Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0098609 cell-cell adhesion	IBA GO_REF:0000033	ACCEPT	Summary: Phylogenetic inference of a cell-cell adhesion role is strongly corroborated by direct experimental evidence for this gene product; TgrC1/gp150 is a bona fide cell adhesion molecule. Reason: Cell-cell adhesion is a well-established core role of TgrC1, supported by decades of gp150/lagC biochemistry and by TgrB1-TgrC1 binding studies. Supporting Evidence: PMID:1577768 provide direct evidence that gp150 is a cell-cell adhesion molecule involved in cell-cell binding in the postaggregation stage of Dictyostelium development
GO:0009897 external side of plasma membrane	IBA GO_REF:0000033	ACCEPT	Summary: TgrC1 is a type I transmembrane protein whose large glycosylated extracellular domain (and IPT/TIG binding region) faces outward, where it engages TgrB1 on adjacent cells. The external-side location is correct. Reason: The functional (ligand) portion of TgrC1 is displayed on the external side of the plasma membrane, consistent with its heterophilic trans-binding to TgrB1. Supporting Evidence: PMID:23477311 Both TgrB1 and TgrC1 are type I transmembrane proteins, which contain three extracellular IPT/TIG
GO:0031152 aggregation involved in sorocarp development	IBA GO_REF:0000033	KEEP AS NON CORE	Summary: TgrC1 is expressed at aggregation/post-aggregation and is required for progression beyond the loose aggregate stage, so a role within sorocarp aggregation/development is correct, but it is a developmental process rather than the core molecular function. Reason: The aggregation/development role is a downstream consequence of TgrC1-mediated adhesion and allorecognition; it is retained as a non-core biological process. Supporting Evidence: PMID:7926779 Mutant cells aggregate normally but are unable to proceed past the loose aggregate stage
GO:0005886 plasma membrane	IEA GO_REF:0000044	ACCEPT	Summary: Plasma membrane localization is correct and independently established by direct experimental evidence for gp150/TgrC1. Reason: TgrC1 is a single-pass plasma membrane glycoprotein, consistent with its role as a cell-surface adhesion ligand. Supporting Evidence: PMID:11071787 gp150 is a membrane glycoprotein which has been implicated in cell-cell adhesion in the postaggregation stages of Dictyostelium development
GO:0007165 signal transduction	IEA GO_REF:0000108	KEEP AS NON CORE	Summary: TgrC1 participates in signaling as the ligand that triggers TgrB1 receptor activation, but "signal transduction" is a broad inter-ontology inference. The cell-autonomous signaling activity resides in the TgrB1 receptor, whereas TgrC1 acts non-cell-autonomously as the ligand. Reason: The general term is not wrong (TgrC1 binding induces TgrB1 phosphorylation and downstream signaling) but is non-specific; TgrC1's core molecular role is as an adhesion ligand, not as a signal transducer per se. Supporting Evidence: PMID:29038229 The TgrB1 cytoplasmic tail is essential for its function and it becomes phosphorylated upon association with TgrC1
GO:0070161 anchoring junction	IEA GO_REF:0000044	ACCEPT	Summary: This is a UniProt subcellular-location mapping from the "Cell junction" keyword. TgrC1 is enriched at cell-cell contacts, and adherens junction-like structures have been described in Dictyostelium, consistent with the experimental annotations to this term. Reason: Enrichment of gp150/TgrC1 at cell-cell junctions/contact sites is documented experimentally; this electronic mapping agrees with those annotations and is retained as a localization. Supporting Evidence: PMID:15561583 adherens junction-like structures have been discovered in the fruiting body
GO:0005886 plasma membrane	EXP PMID:11071787 The membrane glycoprotein gp150 is encoded by the lagC gene ...	ACCEPT	Summary: Direct experimental localization of gp150/TgrC1 to the membrane and cell-cell contact regions. Reason: gp150 is directly shown to be a membrane glycoprotein enriched at cell-cell contacts, a core plasma membrane localization. Supporting Evidence: PMID:11071787 Immunolocalization studies have confirmed its enrichment in cell-cell contact regions
GO:0005886 plasma membrane	EXP PMID:15561583 Regulation of cell-cell adhesion during Dictyostelium develo...	ACCEPT	Summary: Review documenting lagC (gp150) as a developmentally regulated cell adhesion molecule at the plasma membrane. Reason: Plasma membrane localization of the gp150/lagC adhesion system is well established. Supporting Evidence: PMID:15561583 the adhesion genes, cadA (encoding DdCAD-1), csaA (gp80) and lagC (gp150)
GO:0005886 plasma membrane	EXP PMID:1577768 Purification and partial characterization of a cell adhesion...	ACCEPT	Summary: gp150 was purified as a cell surface glycoprotein mediating EDTA-resistant cell-cell adhesion. Reason: The purified adhesion molecule is a cell-surface/plasma membrane glycoprotein. Supporting Evidence: PMID:1577768 A cell surface glycoprotein of apparent Mr 150,000 (gp150) has been implicated in mediating EDTA-resistant cell-cell adhesion in Dictyostelium discoideum
GO:0005886 plasma membrane	EXP PMID:498273 Identification of a cell surface glycoprotein involved in ce...	ACCEPT	Summary: The founding study identifying gp150 as a developmentally regulated cell-surface glycoprotein that accumulates on aggregating cells. Reason: gp150 accumulates on the cell surface of aggregating cells, a core plasma membrane localization. Supporting Evidence: PMID:498273 there is a rapid accumulation of gp150 on the surfaces of aggregating cells
GO:0005886 plasma membrane	EXP PMID:7407916 A glycoprotein involved in aggregation of D. discoideum is d...	ACCEPT	Summary: gp150 was shown by immuno-EM to be closely associated with the plasma membrane and enriched at cell contacts. Reason: Direct ultrastructural evidence places gp150 at the plasma membrane. Supporting Evidence: PMID:7407916 gp150 was closely associated with the plasma membrane
GO:0070161 anchoring junction	EXP PMID:11071787 The membrane glycoprotein gp150 is encoded by the lagC gene ...	ACCEPT	Summary: gp150/TgrC1 is enriched in cell-cell contact regions, consistent with a junction-associated localization. Reason: Experimental immunolocalization documents enrichment at cell-cell contact/junction regions; retained as a localization, deferring to the curator on the specific junction term. Supporting Evidence: PMID:11071787 Immunolocalization studies have confirmed its enrichment in cell-cell contact regions
GO:0070161 anchoring junction	EXP PMID:15561583 Regulation of cell-cell adhesion during Dictyostelium develo...	ACCEPT	Summary: Adherens junction-like structures were described in the Dictyostelium fruiting body, and lagC/gp150 is one of the adhesion systems involved. Reason: Junction-associated localization of the lagC/gp150 adhesion system is documented; retained as a localization. Supporting Evidence: PMID:15561583 adherens junction-like structures have been discovered in the fruiting body
GO:0070161 anchoring junction	EXP PMID:1577768 Purification and partial characterization of a cell adhesion...	ACCEPT	Summary: gp150 mediates cell-cell binding at cell contacts; localization to cell-junction regions is consistent with the broader gp150 literature, although this abstract emphasizes adhesion rather than junction ultrastructure. Reason: Experimental (curator read full text); junction-associated localization is consistent with gp150 enrichment at sites of cell contact. Supporting Evidence: PMID:7407916 we found a distribution gradient of gp150 wherein the concentration was enriched at or near sites of cell contact
GO:0070161 anchoring junction	EXP PMID:7407916 A glycoprotein involved in aggregation of D. discoideum is d...	ACCEPT	Summary: gp150 is distributed on the cell surface in a nonrandom fashion favoring cell junctions/contact sites. Reason: Direct evidence for enrichment of gp150 at cell junctions/contact sites. Supporting Evidence: PMID:7407916 we found a distribution gradient of gp150 wherein the concentration was enriched at or near sites of cell contact
GO:0009642 response to light intensity	HEP PMID:41057014 Transcriptomic and metabolomic insights into light-mediated ...	MARK AS OVER ANNOTATED	Summary: This HEP annotation derives from a transcriptomic screen in which tgrC1 (lagC) mRNA was downregulated under dark relative to light incubation. This reflects light-dependent transcriptional regulation of tgrC1, not a function of TgrC1 in sensing or mediating a response to light. Reason: A change in tgrC1 transcript level with light exposure is a high-throughput, expression-based observation; it does not indicate that TgrC1 mediates a response to light intensity, and it is far from the protein's core adhesion/ligand function. Supporting Evidence: PMID:41057014 both of which were downregulated under the dark condition from transcriptomic analysis in the unicellular phase
GO:0005515 protein binding	IPI PMID:23477311 TgrC1 mediates cell-cell adhesion by interacting with TgrB1 ...	MODIFY	Summary: The IPI interaction here is with TgrB1, the receptor for which TgrC1 is the heterophilic ligand. Bare "protein binding" is uninformative; a more specific molecular function (receptor ligand activity) captures the biology. Reason: TgrC1 binds TgrB1 via mutual IPT/TIG domains; since TgrB1 is the receptor and TgrC1 the ligand, receptor ligand activity is the informative molecular function. Proposed replacements: receptor ligand activity Supporting Evidence: PMID:23477311 far-Western blotting coupled with MS to identify TgrB1 as the heterophilic binding partner of TgrC1
GO:0048018 receptor ligand activity	IDA PMID:29038229 The polymorphic proteins TgrB1 and TgrC1 function as a ligan...	ACCEPT	Summary: Direct genetic/biochemical evidence that TgrC1 functions as the ligand for the TgrB1 receptor in cooperative aggregation and differentiation. This is the core molecular function of TgrC1. Reason: Merodiploid experiments demonstrate that TgrC1 acts non-cell-autonomously as the ligand while TgrB1 is the cell-autonomous receptor. Supporting Evidence: PMID:29038229 TgrB1 acts as a receptor with TgrC1 as its ligand in cooperative aggregation and differentiation PMID:29038229 These non-cell-autonomous phenotypes indicate that TgrC1 functions as a ligand and TgrB1 does not
GO:0005911 cell-cell junction	IDA PMID:7407916 A glycoprotein involved in aggregation of D. discoideum is d...	ACCEPT	Summary: gp150/TgrC1 is enriched at sites of cell contact, where it mediates cell-cell adhesion. Cell-cell junction is an appropriate site of action. Reason: Direct localization evidence places gp150 at cell-cell junctions/contact sites, where its adhesion function operates. Supporting Evidence: PMID:7407916 we found a distribution gradient of gp150 wherein the concentration was enriched at or near sites of cell contact
GO:0007157 heterophilic cell-cell adhesion	IDA PMID:23477311 TgrC1 mediates cell-cell adhesion by interacting with TgrB1 ...	ACCEPT	Summary: TgrC1 mediates heterophilic cell-cell adhesion via its interaction with the distinct partner TgrB1 through mutual IPT/TIG domains. This is a core role. Reason: The adhesion is heterophilic (TgrC1 binds a different protein, TgrB1), directly demonstrated by binding and mapping studies. Supporting Evidence: PMID:23477311 The heterophilic adhesion protein TgrC1 (Tgr is transmembrane, IPT, IG, E-set, repeat protein) is expressed during cell aggregation PMID:23477311 we have mapped the cell-binding regions in these two proteins to Lys(537)-Ala(783) in TgrB1 and Ile(336)-Val(360) in TgrC1
GO:0005886 plasma membrane	TAS PMID:15261655 Dictyostelium morphogenesis.	ACCEPT	Summary: Plasma membrane site of action is correct for TgrC1; contact-dependent adhesion/signaling at the membrane is central to its role, though this particular review does not name tgrC1. Reason: The plasma membrane location is independently well established for TgrC1; the site of action annotation is appropriate. Supporting Evidence: PMID:11071787 gp150 is a membrane glycoprotein which has been implicated in cell-cell adhesion in the postaggregation stages of Dictyostelium development
GO:0009986 cell surface	IDA PMID:498273 Identification of a cell surface glycoprotein involved in ce...	ACCEPT	Summary: The original identification of gp150 as a cell-surface glycoprotein that accumulates on aggregating cells. Reason: Direct cell-surface localization of gp150, consistent with its cell-surface adhesion ligand role. Supporting Evidence: PMID:498273 there is a rapid accumulation of gp150 on the surfaces of aggregating cells
GO:0005911 cell-cell junction	IDA PMID:11071787 The membrane glycoprotein gp150 is encoded by the lagC gene ...	ACCEPT	Summary: gp150/TgrC1 is enriched in cell-cell contact regions, an appropriate site of action for its adhesion function. Reason: Immunolocalization shows enrichment at cell-cell contacts/junctions. Supporting Evidence: PMID:11071787 Immunolocalization studies have confirmed its enrichment in cell-cell contact regions
GO:0098635 protein complex involved in cell-cell adhesion	IDA PMID:24490801 Assembly of the TgrB1-TgrC1 cell adhesion complex during Dic...	ACCEPT	Summary: TgrC1 is an active unit of the assembled TgrB1-TgrC1 adhesion complex, which forms large clusters at cell-cell contacts. This is a core complex membership. Reason: TgrC1 homodimers and TgrB1 dimers coalesce into large adhesion complexes that mediate cell-cell adhesion. Supporting Evidence: PMID:24490801 the coalescence of TgrB1-TgrC1 clusters results in the formation of large adhesion complexes
GO:0042802 identical protein binding	IPI PMID:24490801 Assembly of the TgrB1-TgrC1 cell adhesion complex during Dic...	ACCEPT	Summary: TgrC1 spontaneously forms cis-homodimers, demonstrated by split-GFP complementation and chemical cross-linking. Homodimerization is required to nucleate assembly of the adhesion complex. Reason: Self-association (identical protein binding) is a genuine and functionally important property of TgrC1 that initiates TgrB1-TgrC1 complex assembly. Supporting Evidence: PMID:24490801 The ability of TgrC1 to form cis-homodimers spontaneously was demonstrated by fluorescence complementation studies and confirmed by chemical cross-linking
GO:0007157 heterophilic cell-cell adhesion	IMP PMID:11071787 The membrane glycoprotein gp150 is encoded by the lagC gene ...	ACCEPT	Summary: Loss and gain of gp150 function demonstrate that it mediates cell-cell adhesion via heterophilic interaction with another (aggregation-stage) component, later identified as TgrB1. Reason: Mutant/transgenic evidence establishes gp150 as a heterophilic adhesion molecule, a core function. Supporting Evidence: PMID:11071787 gp150 mediates cell-cell adhesion via heterophilic interactions with another component that accumulates during the aggregation stage
GO:0009897 external side of plasma membrane	IDA PMID:24490801 Assembly of the TgrB1-TgrC1 cell adhesion complex during Dic...	ACCEPT	Summary: TgrC1 homodimers act on the cell surface, binding TgrB1 in trans across the gap between adjacent cells; the ligand-binding region is on the external side of the plasma membrane. Reason: The functional TgrC1 ectodomain is displayed on the external side of the plasma membrane where it engages TgrB1 in trans. Supporting Evidence: PMID:24490801 the assembly process is initiated upon trans-interaction of monomeric TgrB1 with TgrC1 homodimers on adjacent cells
GO:0009988 cell-cell recognition	IMP PMID:19285397 Polymorphic members of the lag gene family mediate kin discr...	ACCEPT	Summary: Deletion of the polymorphic lagC1 (tgrC1) causes strain segregation from wild-type in chimerae, demonstrating a role in kin/self recognition. Reason: TgrC1 is a determinant of cell-cell (kin) recognition, a core organismal role tightly linked to its allele-specific adhesion function. Supporting Evidence: PMID:19285397 Deleting lagB1 and lagC1 results in strain segregation in chimeras with wild-type cells PMID:19285397 lagB1 and lagC1 participate in a common self- or kin-recognition mechanism in D. discoideum
GO:0016338 calcium-independent cell-cell adhesion	IGI PMID:11071787 The membrane glycoprotein gp150 is encoded by the lagC gene ...	ACCEPT	Summary: gp150/TgrC1 mediates EDTA-resistant (i.e., calcium-independent) cell-cell adhesion, distinguishing it from the calcium-dependent DdCAD-1 system. Reason: The adhesion mediated by gp150 is EDTA-resistant/calcium-independent, a defining property. Supporting Evidence: PMID:11071787 these cells acquire EDTA-resistant cell-cell binding during aggregation
GO:0097656 cell-cell self recognition	IGI PMID:21700835 Self-recognition in social amoebae is mediated by allelic pa...	ACCEPT	Summary: A matching pair of tgrB1 and tgrC1 alleles is necessary and sufficient for attractive self-recognition, mediated by differential cell-cell adhesion. Reason: TgrC1 is a direct determinant of self-recognition, established by allele-swap genetics. Supporting Evidence: PMID:21700835 a matching pair of tgrB1 and tgrC1 alleles is necessary and sufficient for attractive self-recognition, which is mediated by differential cell-cell adhesion
GO:0099120 socially cooperative development	IMP PMID:23910661 Kin recognition protects cooperators against cheaters.	KEEP AS NON CORE	Summary: The tgrB1/tgrC1 kin-recognition system underlies cooperative multicellular development and protects cooperators against cheaters. This is a broad social/developmental process downstream of TgrC1's adhesion/recognition function. Reason: Socially cooperative development is an organismal-level process enabled by TgrC1-mediated kin recognition; retained as a non-core biological process. Supporting Evidence: PMID:23910661 This mechanism is mediated by two transmembrane proteins, TgrB1 and TgrC1
GO:0099138 altruistic, chimeric sorocarp development	IDA PMID:28120827 A polychromatic 'greenbeard' locus determines patterns of co...	KEEP AS NON CORE	Summary: The polymorphic Tgr locus (tgrB1/tgrC1) acts as a polychromatic greenbeard that determines partner-specific cooperation and segregation in chimeric development. This is a high-level social process. Reason: Altruistic, chimeric sorocarp development is an organismal social outcome of TgrC1-mediated allorecognition/adhesion; retained as non-core. Supporting Evidence: PMID:28120827 a matching pair of tgrB1 and tgrC1 alleles is necessary and sufficient for attractive self-recognition and cell-cell adhesion
GO:0031149 sorocarp stalk cell differentiation	IGI PMID:25894230 TgrC1 Has Distinct Functions in Dictyostelium Development an...	KEEP AS NON CORE	Summary: Suppressor genetics show that tgrC1 regulates stalk cell differentiation in a cell-autonomous manner, separable from its kin-recognition function. This is a downstream developmental role. Reason: Regulation of stalk differentiation is a downstream developmental consequence of TgrC1 function rather than its core molecular activity. Supporting Evidence: PMID:25894230 tgrC1 regulates stalk differentiation in a cell-autonomous manner and spore differentiation in a non-cell-autonomous manner
GO:0031152 aggregation involved in sorocarp development	IEP PMID:25887420 Leaps and lulls in the developmental transcriptome of Dictyo...	KEEP AS NON CORE	Summary: Developmental transcriptome profiling places tgrC1 expression at the aggregate-to-mound transition, where tgrB1/tgrC1 constitute a checkpoint for development beyond aggregation. This is an expression-based (IEP) developmental inference. Reason: The aggregation/development role is a downstream biological process; the IEP expression evidence supports timing rather than the core molecular function. Supporting Evidence: PMID:25887420 In order for D. discoideum to develop beyond the aggregation stage into mounds, amoebae must clear a checkpoint established by the allorecognition genes tgrB1 and tgrC1
GO:0098609 cell-cell adhesion	IDA PMID:1577768 Purification and partial characterization of a cell adhesion...	ACCEPT	Summary: Purified gp150 directly inhibits post-aggregation cell reassociation and binds saturably to cells, providing direct evidence that it is a cell-cell adhesion molecule. Reason: Core adhesion function directly demonstrated with purified gp150. Supporting Evidence: PMID:1577768 provide direct evidence that gp150 is a cell-cell adhesion molecule involved in cell-cell binding in the postaggregation stage of Dictyostelium development
GO:1902168 response to catechin	IDA PMID:23516620 The green tea catechin epigallocatechin gallate (EGCG) block...	KEEP AS NON CORE	Summary: In EGCG-treated cells, tgrC expression is delayed along with other late-aggregate/early-mound genes. This reflects a transcriptional/developmental response to catechin, not a core molecular function of TgrC1. Reason: tgrC responds to catechin treatment by delayed expression, a peripheral (non-core) response secondary to catechin's block of aggregation and motility. Supporting Evidence: PMID:23516620 The delays in expression were also observed for tgrC and gbfA, genes expressed from late aggregate to early mound stage
GO:0031152 aggregation involved in sorocarp development	IMP PMID:7926779 LagC is required for cell-cell interactions that are essenti...	KEEP AS NON CORE	Summary: lagC-null cells aggregate but arrest at the loose aggregate stage and fail subsequent development, showing lagC/TgrC1 acts within post-aggregation sorocarp development. Reason: The developmental arrest phenotype supports a role within sorocarp development, a downstream biological process rather than the core molecular function. Supporting Evidence: PMID:7926779 lagC- null cells aggregate but then disaggregate and reaggregate to form small granular mounds
GO:0031152 aggregation involved in sorocarp development	IMP PMID:14651934 A cell-adhesion pathway regulates intercellular communicatio...	KEEP AS NON CORE	Summary: lagC is the terminal node of a comC-lagC-lagD cell-adhesion/communication pathway required for sporulation, acting within multicellular development. Reason: Role within the sorocarp developmental/signaling pathway is a downstream process; retained as non-core. Supporting Evidence: PMID:14651934 the cell adhesion gene lagC is the terminal node in this signaling network

Gene Description

Existing Annotations Review

Core Functions

TgrC1 self-associates into cis-homodimers on the surface of one cell; these homodimers bind monomeric TgrB1 on the neighboring cell and nucleate the coalescence of large TgrB1-TgrC1 clusters into the cell-cell adhesion complex.

References

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