TLS Online TPP Program

#Id: 1577

#Unit 4. Cell Communication and Cell Signaling

β-catenin binds to TCF to displace the Gro repressor and recruits co-activator proteins Pygo, LGS, to activate target gene expression.

TLS Online TPP Program

#Id: 1578

#Unit 4. Cell Communication and Cell Signaling

Active Wnt signaling leads to the secretion of Notum.

 

TLS Online TPP Program

#Id: 1579

#Unit 4. Cell Communication and Cell Signaling

Notum, a hydrolase that associates with glypican and then cleaves off Wnt’s attached lipids in a process of deacylation or delipidation.

TLS Online TPP Program

#Id: 1580

#Unit 4. Cell Communication and Cell Signaling

Delipidation process reduces Wnt signaling, creates a negative feedback mechanism for preventing excessive Wnt signaling.

TLS Online TPP Program

#Id: 1581

#Unit 4. Cell Communication and Cell Signaling

Frizzled receptor possesses a unique hydrophobic cleft adapted to interact with lipidated Wnts, a binding conformation mimicked in Notum’s structure as well.

  

TLS Online TPP Program

#Id: 1582

#Unit 4. Cell Communication and Cell Signaling

Antagonists of Wnt:

Secreted frizzled-related protein (Sfrp)

Wnt inhibitory factor (Wif)

Dickkopf (Dkk) family