The ER captures selected proteins from the cytosol as they are being synthesized. These are of two types:

Transmembrane proteins

Water-soluble proteins

TLS Online TPP Program

#Id: 9977

#XL - T Zoology

Unphosphorylated β-catenin translocates to the nucleus.

TLS Online TPP Program

#Id: 9978

#XL - T Zoology

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: 9979

#XL - T Zoology

Active Wnt signaling leads to the secretion of Notum.

TLS Online TPP Program

#Id: 9980

#XL - T Zoology

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: 9981

#XL - T Zoology

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

TLS Online TPP Program

#Id: 9982

#XL - T Zoology

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