Abstract
In mammals, two inhibitory Smads (I-Smads), Smad6 and Smad7, play pivotal roles in negative regulation of TGF-beta family signaling. Smad7 ubiquitously inhibits TGF-beta family signaling, whereas Smad6 inhibits signaling from the ALK-3/6 subfamily in preference to that from the ALK-1/2 and ALK-4/5/7 subfamilies of TGF-beta family type I receptors. In Drosophila, only one I-Smad, Dad, has been identified. Here we examined inhibitory effects of Dad on type I receptors in Drosophila. Dad inhibited Saxophone (ALK-1/2 orthologue) and Thickveins (ALK-3/6 orthologue) but not Baboon (ALK-4/5/7 orthologue). The differential modes of action of I-Smads in mammals and Drosophila are discussed.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Activin Receptors / antagonists & inhibitors*
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Activin Receptors / metabolism
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Animals
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DNA-Binding Proteins / metabolism
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Drosophila Proteins / antagonists & inhibitors*
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Drosophila Proteins / metabolism*
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Drosophila melanogaster / metabolism*
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Humans
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Phosphorylation
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Protein Serine-Threonine Kinases / antagonists & inhibitors*
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Protein Serine-Threonine Kinases / metabolism
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Receptors, Cell Surface / antagonists & inhibitors*
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Receptors, Cell Surface / metabolism
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Receptors, Transforming Growth Factor beta / antagonists & inhibitors*
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Receptors, Transforming Growth Factor beta / metabolism
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Smad4 Protein / metabolism
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Transcription Factors / metabolism
Substances
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DNA-Binding Proteins
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Dad protein, Drosophila
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Drosophila Proteins
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MAD protein, Drosophila
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Med protein, Drosophila
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Receptors, Cell Surface
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Receptors, Transforming Growth Factor beta
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Smad4 Protein
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Transcription Factors
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sax protein, Drosophila
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tkv protein, Drosophila
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Protein Serine-Threonine Kinases
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Activin Receptors
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Babo protein, Drosophila