Abstract
Smad3 is a direct mediator of transcriptional activation by the TGFβ receptor. Its target genes in epithelial cells include cyclin-dependent kinase inhibitors that generate a cytostatic reponse. We defined how, in the same context, Smad3 can also mediate transcriptional repression of the growth-promoting gene c-myc. A complex containing Smad3, the transcription factors E2F4/5 and DP1, and the corepressor p107 preexists in the cytoplasm. In response to TGFβ, this complex moves into the nucleus and associates with Smad4, recognizing a composite Smad-E2F site on c-myc for repression. Previously known as the ultimate recipients of cdk regulatory signals, E2F4/5 and p107 act here as transducers of TGFβ receptor signals upstream of cdk. Smad proteins therefore mediate transcriptional activation or repression depending on their associated partners.
Original language | English (US) |
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Pages (from-to) | 19-32 |
Number of pages | 14 |
Journal | Cell |
Volume | 110 |
Issue number | 1 |
DOIs | |
State | Published - Jul 12 2002 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- General Biochemistry, Genetics and Molecular Biology