title: Synergistic signaling by two BMP ligands through the SAX and TKV receptors controls wing growth and patterning in Drosophila.
abstract: In Drosophila wing discs, a morphogen gradient of DPP has been proposed to determine the transcriptional response thresholds of the downstream genes sal and omb. We present evidence that the concentration of the type I receptor TKV must be low to allow long-range DPP diffusion. Low TKV receptor concentrations result, however, in low signaling activity. To enhance signaling at low DPP concentrations, we find that a second ligand, GBB, augments DPP/TKV activity. GBB signals primarily through the type I receptor SAX, which synergistically enhances TKV signaling and is required for proper OMB expression. We show that OMB expression in wing discs requires synergistic signaling by multiple ligands and receptors to overcome the limitations imposed on DPP morphogen function by receptor concentration levels.
authors.affiliation: Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA.
authors.forename: T E
authors.initials: TE
authors.lastname: Haerry
authors.forename: O
authors.initials: O
authors.lastname: Khalsa
authors.forename: M B
authors.initials: MB
authors.lastname: O'Connor
authors.forename: K A
authors.initials: KA
authors.lastname: Wharton
mesh_terms: D000818:Animals; D019521:Body Patterning; D004268:DNA-Binding Proteins / Q000032:analysis / Q000235:genetics; D004058:Diffusion; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000235:genetics; D010641:Phenotype; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism*; D017384:Sequence Deletion / Q000235:genetics; D015398:Signal Transduction; D020825:T-Box Domain Proteins; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism*; D014921:Wings, Animal / Q000196:embryology* / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D019476:Insect Proteins; D009419:Nerve Tissue Proteins; D011956:Receptors, Cell Surface; D018125:Receptors, Transforming Growth Factor beta; D020825:T-Box Domain Proteins; D016212:Transforming Growth Factor beta; C064196:dpp protein, Drosophila; C089440:gbb protein, Drosophila; C086338:sax protein, Drosophila; C072962:bi protein, Drosophila; C090169:tkv protein, Drosophila; D017346:Protein Serine-Threonine Kinases