Six DnaC monomers bind to each hexamer of DnaB, and this complex binds to the origin.

TLS Online TPP Program

#Id: 9370

#Unit 4. Cell Communication and Cell Signaling

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

TLS Online TPP Program

#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

TLS Online TPP Program

#Id: 9373

#Unit 4. Cell Communication and Cell Signaling

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

TLS Online TPP Program

#Id: 9374

#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.

TLS Online TPP Program

#Id: 9446

#Unit 4. Cell Communication and Cell Signaling

The cytokines form a family of relatively small, secreted signaling molecules:

Contain about 160–200 AA

4 long, conserved α helices

Control growth and differentiation