Gene Ontology annotation through association of InterPro records with GO terms
Electronic Gene Ontology annotations created by transferring manual GO annotations between related proteins based on shared sequence features
Combined Automated Annotation using Multiple IEA Methods
Involvement of Tcf/Lef in establishing cell types along the animal-vegetal axis of sea urchins.
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SpTcf/Lef was cloned from S. purpuratus and its expression peaks when beta-catenin enters vegetal nuclei.
"Expression of SpTcf/Lef was maximal when beta-catenin became localized to nuclei of vegetal blastomeres, consistent with its acting in combination with beta-catenin to specify vegetal cell fates."
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A dominant-negative SpTcf/Lef phenocopies loss of nuclear beta-catenin, abolishing mesenchyme, endoderm and aboral ectoderm.
"Expression of a dominant-negative SpTcf/Lef inhibited primary and secondary mesenchyma, endoderm, and aboral ectoderm formation in a manner similar to that observed when nuclear accumulation of beta-catenin was prevented."
TCF is the nuclear effector of the beta-catenin signal that patterns the sea urchin animal-vegetal axis.
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Dominant-negative TCF animalizes and activated TCF vegetalizes the embryo.
"We show that expression of a dominant negative TCF results in a classic "animalized" embryo. In contrast, microinjected RNA encoding an activated TCF produces a highly "vegetalized" embryo."
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All of beta-catenin's axis-patterning activity is mediated through TCF, acting between fertilization and the 60-cell stage.
"We also provide evidence indicating that all of beta-catenin's activity in patterning the sea urchin AV axis is mediated by TCF."
Nuclear beta-catenin is required to specify vegetal cell fates in the sea urchin embryo.
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Nuclear beta-catenin accumulates cell-autonomously in endomesoderm precursors and is required for all vegetal fates and for micromere signalling.
"the accumulation of beta-catenin in nuclei of vegetal cells is regulated cell autonomously and that this localization is required for the establishment of all vegetal cell fates and the production of micromere-derived signals"
LvGroucho and nuclear beta-catenin functionally compete for Tcf binding to influence activation of the endomesoderm gene regulatory network in the sea urchin embryo.
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Groucho binds Tcf through its Q and WD domains and antagonizes endomesoderm gene expression.
"Interaction assays demonstrate that LvGroucho interacts with Tcf via both the Q and the WD domains of the protein. LvGroucho interacts with Tcf to antagonize the expression of key endomesoderm regulatory genes."
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Groucho and nuclear beta-catenin compete for Tcf binding, forming the switch that initiates the endomesoderm GRN.
"LvGroucho functionally competes with beta-catenin for Tcf binding, and this competitive mechanism regulates one of the earliest steps in the initiation of the sea urchin endomesoderm GRN"
cis-Regulatory inputs of the wnt8 gene in the sea urchin endomesoderm network.
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Tcf1/beta-catenin and Blimp1 sites are both required for endomesodermal expression of a S. purpuratus wnt8 cis-regulatory module.
"The Tcf1/beta-catenin and Blimp1/Krox inputs are both necessary for normal endomesodermal expression mediated by this cis-regulatory module"
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In a second wnt8 module, Tcf1 sites repress ectopic transcription in prospective ectoderm.
"In a second regulatory region, which initiates expression in micromere and macromere descendant cells early in cleavage, Tcf1 sites act to repress ectopic transcription in prospective ectoderm cells."
Nemo-like kinase (NLK) acts downstream of Notch/Delta signalling to downregulate TCF during mesoderm induction in the sea urchin embryo.
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TCF activity is required early to launch the endomesoderm GRN but must be shut off by NLK in the mesodermal lineage at blastula stage.
"activating the expression of a TCF-VP16 construct at blastula stages strongly inhibits endoderm and mesoderm formation, indicating that while TCF activity is required early for launching the endomesoderm gene regulatory network, it has to be downregulated at blastula stage in the mesodermal lineage"
Global regulatory logic for specification of an embryonic cell lineage.
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Nuclear beta-catenin forms an active complex with Tcf in the micromeres, and beta-catenin/Tcf plus Otx activates pmar1.
"The pmar1 genes are activated by the β-catenin/Tcf transcription complex plus Otx, i.e., by two of the micromere-specific inputs just enumerated ( 25 , 30 )."
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wnt8 expression in the micromere lineage requires Blimp1 and beta-catenin/Tcf.
"the inputs required for its expression in the micromere lineage are Blimp1 and β-catenin/Tcf"
A gene regulatory network controlling the embryonic specification of endoderm.
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Most early veg2 endoderm regulatory genes are under cis-regulatory Tcf control, and the same sites later extinguish the endoderm GRN in mesoderm precursors.
"the same Tcf sites that are used to initiate the endoderm GRN in the veg2 lineage are used again to extinguish it in mesoderm precursors"
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In Notch-receiving cells, reduced nuclear beta-catenin leads to Tcf/Groucho repression.
"A possible explanation is that in cells receiving Notch signalling, the availability of nuclear β-catenin is reduced, leading to Tcf/Groucho-mediated repression."
Gene regulatory network subcircuit controlling a dynamic spatial pattern of signaling in the sea urchin embryo.
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wnt8 requires beta-catenin/Tcf and Blimp1 inputs, so Tcf both receives and propagates the Wnt8 signal.
"the wnt8 gene requires inputs from both β-catenin/Tcf (i.e., from the same signal transduction system that it activates) and from Blimp1 factor for expression"