Allelic exclusion - Once allele’s functional protein is generated, rearrangement at the other allele is shut down

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.

TLS Online TPP Program

#Id: 9969

#XL - T Zoology

Homologs

LRP in vertebrates = Arrow in Drosophila

TLS Online TPP Program

#Id: 9970

#XL - T Zoology

In the absence of Wnts,

“free” β-catenin are targeted for degradation by a cytosolic destruction complex that is held together by the tumor suppressor protein Axin.