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General Information
Toll Signaling Pathway
D. melanogaster
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In Drosophila, the canonical Toll signaling pathway is initiated by the binding of a spatzle ligand to Toll (Tl) or a Toll-like receptor leading to the nuclear localization of the NF-κB (dl or Dif) transcription factor. Activation of the pathway is controlled by the generation of a cleaved, active, Toll-binding form of spatzle ligand. Proteolytic activation of spatzle ligand lies downstream of several zymogen activation cascades that are initiated by different cues. The canonical Toll pathway is best characterised in the establishment of embryonic dorsal-ventral pattern and innate immunity. In dorsal-ventral patterning, localized activation of spz results in ventral nuclear accumulation of dl. During gram-positive bacterial, viral and fungal immune challenge, a zymogen cascase is activated by extracellular pattern recognition receptors or virulence factor-mediated cleavage of the zymogen persephone (psh). (Adapted from FBrf0091014 and FBrf0223077).

Notes and selected reviews

Selected publications for background information: The Drosophila toll signaling pathway (FBrf0212695), Maternal control of the Drosophila dorsal-ventral body axis (FBrf0225950) and Innate immunity in Drosophila: Pathogens and pathways (FBrf0203021).

Note: Pathway Pages in FlyBase are under development. The pathway gene tables display genes that have been experimentally shown to act within the pathway or modify pathway activity. We welcome any feedback to help improve the usefulness and accuracy of these gene lists.

Biological Process Gene Ontology (GO) term(s)
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Members (61)
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[Illustration - Comparison of Drosophila immune deficiency (imd), Toll, and mammalian TLR signaling pathways.(The Interactive Fly)](

[KEGG Pathway - Toll and Imd signaling pathway - Drosophila melanogaster](

[Reactome Pathway - Toll](

[Wikipathways - Toll, IMD, JAK/STAT Pathways for Immune Response to Pathogens (Drosophila melanogaster)]( Pathway:WP3830 )

Synonyms and Secondary IDs
Toll Signaling Pathway
Secondary FlyBase ID(s)
References (85)