Regulation of TGFβ receptor trafficking and signaling by atypical protein kinase C

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Adrian Gunaratne1, Hassina Benchabane, Gianni M Di Guglielmo

  • 1Department of Physiology and Pharmacology, University of Western Ontario, London, ON, Canada.

Cellular Signalling
|September 20, 2011
PubMed

Insights

Protein Kinase C (PKC) regulates transforming growth factor beta (TGFβ) receptor trafficking and signaling. Inhibiting PKC or specific atypical isoforms like PKCι and PKCζ delays receptor degradation, extending TGFβ signaling pathways.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Biochemistry

Background:

  • Transforming growth factor beta (TGFβ) signaling is crucial for cellular processes.
  • TGFβ receptor trafficking is intrinsically linked to signal transduction.
  • Protein Kinase C (PKC) family kinases modulate endocytic pathways for various cell surface receptors.

Purpose of the Study:

  • To investigate the role of PKC activity in TGFβ receptor trafficking and signaling.
  • To identify specific PKC isoforms involved in regulating TGFβ receptor dynamics.
  • To elucidate the mechanism by which PKC influences TGFβ-mediated cellular responses.

Main Methods:

  • Immunofluorescence microscopy to visualize receptor localization.
  • (125)I-TGFβ internalization assays to quantify receptor uptake.
  • siRNA-mediated knockdown of atypical PKC isoforms (PKCι and PKCζ).

Main Results:

  • Pharmacological inhibition of PKC altered TGFβ receptor trafficking and delayed receptor degradation.
  • PKC inhibition prolonged TGFβ-dependent Smad2 phosphorylation.
  • Knockdown of atypical PKC isoforms (PKCι, PKCζ) also delayed TGFβ receptor degradation and extended signaling.

Conclusions:

  • Atypical PKC isoforms, specifically PKCι and PKCζ, regulate TGFβ signaling.
  • These PKC isoforms control TGFβ signaling by modulating cell surface receptor trafficking and degradation pathways.

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