The Drosophila Activin-like ligand Dawdle signals preferentially through one isoform of the Type-I receptor Baboon.
How TGF-beta-type ligands achieve signaling specificity during development is only partially understood. Here, we show that Dawdle, one of four Activin-type ligands in Drosophila, preferentially signals through Babo(c), one of three isoforms of the Activin Type-I receptor that are expressed during development. In cell culture, Dawdle signaling is active in the presence of the Type-II receptor Punt but not Wit, demonstrating that the Type-II receptor also contributes to the specificity of the signaling complex. During development, different larval tissues express unique combinations of these receptors, and ectopic expression of Babo(c) in a tissue where it is not normally expressed at high levels can make that tissue sensitive to Dawdle signaling. These results reveal a mechanism by which distinct cell types can discriminate between different Activin-type signals during development as a result of differential expression of Type-I receptor isoforms.
Jensen
Philip A
PA
Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN 55455, USA.
Zheng
Xiaoyan
X
Lee
Tzumin
T
O'Connor
Michael B
MB
D029404:Activin Receptors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D030301:Activin Receptors, Type II / Q000378:metabolism; D028341:Activins / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D019521:Body Patterning; D002352:Carrier Proteins / Q000378:metabolism*; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D008024:Ligands; D008969:Molecular Sequence Data; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism; D015398:Signal Transduction; D014921:Wings, Animal / Q000196:embryology / Q000378:metabolism
D002352:Carrier Proteins; C517156:Daw protein, Drosophila; D029721:Drosophila Proteins; D008024:Ligands; D020033:Protein Isoforms; D011956:Receptors, Cell Surface; C449821:wit protein, Drosophila; D028341:Activins; D029404:Activin Receptors; D030301:Activin Receptors, Type II; C517157:Babo protein, Drosophila; C425583:put protein, Drosophila