RII phosphorylates serine and threonine in the juxtamembrane segment of the RI (ligand induced receptor hetero-oligomerization), releasing the inhibition of RI kinase activity.

TLS Online TPP Program

#Id: 9958

#XL - T Zoology

Structure of Wnt proteins 

22 cysteine residues, which form disulfide bridges that maintain a globular secondary structure.

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#Id: 9959

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Wnt = wingless + integrated

TLS Online TPP Program

#Id: 9960

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Wnt proteins are modified by linkage of a monounsaturated fatty acid, palmitoleic acid, to a serine in the middle of the protein.

TLS Online TPP Program

#Id: 9961

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Lipid modifications of Wnt are catalyzed by the 

O-acetyltransferase Porcupine.

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#Id: 9962

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Principal signaling receptor is Frizzled (Fz), contains 

7 TM α helices.

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#Id: 9963

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