Hac1 activates transcription of genes encoding several protein-folding catalysts.

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#Id: 9369

#Unit 4. Cell Communication and Cell Signaling

Negative regulators of TGF-β signaling are induced by TGF-β signaling (Example of Negative feedback): 

Ski 

SnoN 

I-Smads (Smad7)

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#Unit 4. Cell Communication and Cell Signaling

SnoN and Ski trigger abnormal cell proliferation by blocking the Smad-complex.

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#Id: 9371

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 9372

#Unit 4. Cell Communication and Cell Signaling

Ski recruits N-CoR, which binds directly to mSin3A; mSin3A interacts with HDAC, that promotes histone deacetylation on nearby promoters, repressing gene expression

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#Unit 4. Cell Communication and Cell Signaling

Smad7 binds to the activated RI receptors and blocks its ability to phosphorylate Smad2 or Smad3. 

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#Unit 4. Cell Communication and Cell Signaling

Like SOCS proteins in the cytokine signaling, 

Smad7 also recruits an E3 ubiquitin ligase that targets TGF-β receptors for degradation.