Role of Patched-1 Intracellular Domains in Canonical and Non-Canonical Hedgehog Signalling Events

Patched-1 (Ptch1) is the primary receptor for Hedgehog (Hh) ligands and mediates both canonical and non-canonical Hh signalling. Previously, our lab identified that mice possessing a Ptch1 C-terminal truncation display blocked mammary gland development at puberty that is overcome by overexpression o...

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Bibliographic Details
Main Author: Harvey, Malcolm
Other Authors: Hamel, Paul A.
Language:en_ca
Published: 2013
Subjects:
Online Access:http://hdl.handle.net/1807/42877
Description
Summary:Patched-1 (Ptch1) is the primary receptor for Hedgehog (Hh) ligands and mediates both canonical and non-canonical Hh signalling. Previously, our lab identified that mice possessing a Ptch1 C-terminal truncation display blocked mammary gland development at puberty that is overcome by overexpression of activated c-src. Testing the hypothesis that this involves a direct interaction between Ptch1 and c-src, we identified through co-immunoprecipitation that Ptch1 and c-src associate in an Hh-dependent manner, and that the Ptch1 C-terminus regulates activation of c-src in response to Hh ligand. Since the effects of Ptch1 intracellular domain deletions on canonical Hh signalling are ill-defined, we assayed this through luciferase reporter assays and qRT-PCR. Transient assays revealed that the Ptch1 middle intracellular loop is required for response to ligand, while qRT-PCR from primary cells showed that C-terminal truncation impairs canonical Ptch1 function. Together, this indicates that the intracellular domains of Ptch1 mediate distinct canonical and non-canonical functions.