Sar1 is the only GTPase switch protein activated at the ER membrane

TLS Online TPP Program

#Id: 8150

#XL - Q Biochemistry

Sar1 is the only GTPase switch protein activated at the ER membrane

TLS Online TPP Program

#Id: 9963

#XL - T Zoology

The palmitoleate attached to the Wnt protein binds to a specific site on the Fz extracellular domain and stabilizes the Wnt-Fz complex.

TLS Online TPP Program

#Id: 9964

#XL - T Zoology

Wnt signal transduction pathways classify into:

1. Canonical wnt pathway (β-catenin dependent)

2. Noncanonical wnt pathways (β-catenin independent)

TLS Online TPP Program

#Id: 9965

#XL - T Zoology

Noncanonical pathways can be divided into two types: 

1. The “planar cell polarity” pathway

2. The “Wnt/calcium” pathway

TLS Online TPP Program

#Id: 9966

#XL - T Zoology

Central player in the canonical Wnt pathway is β-catenin

TLS Online TPP Program

#Id: 9967

#XL - T Zoology

Homologs

β-catenin in vertebrates = Armadillo in Drosophila

TLS Online TPP Program

#Id: 9968

#XL - T Zoology

“canonical” Wnt signaling uses a second TM protein, LRP that associates with Frizzled in a Wnt signal– dependent manner.