Lysine acetylation 

ε-amino group of a specific lysine of α-tubulin

Microtubules are stabilized against breakage (centrioles, basal bodies, & primary cilia)

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#Unit 4. Cell Communication and Cell Signaling

Noncanonical pathways can be divided into two types: 

1. The “planar cell polarity” pathway

2. The “Wnt/calcium” pathway

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#Unit 4. Cell Communication and Cell Signaling

The central player in the “canonical” Wnt intracellular signal transduction pathway is called β-catenin.

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#Unit 4. Cell Communication and Cell Signaling

Homologs

β-catenin in vertebrates =Armadillo in Drosophila.

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#Unit 4. Cell Communication and Cell Signaling

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

 

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#Unit 4. Cell Communication and Cell Signaling

Homologs

LRP in vertebrates = Arrow in Drosophila.

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#Unit 4. Cell Communication and Cell Signaling

In the absence of Wnts,

β-catenin is bound in a complex with Axin (a scaffold protein), APC, and kinases CK1 and GSK3.