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Oligopeptide Competition Assay for Phosphorylation Site Determination
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Oligopeptide Competition Assay for Phosphorylation Site Determination

Published on: May 18, 2017

Protein kinase D links Gq-coupled receptors to cAMP response element-binding protein (CREB)-Ser133 phosphorylation in

Nazira Ozgen1, Maria Obreztchikova, Jianfen Guo

  • 1Department of Pharmacology, College of Physicians and Surgeons, Columbia University, New York, New York 10032, USA.

The Journal of Biological Chemistry
|April 2, 2008
PubMed

Insights

Protein Kinase D (PKD) is identified as a key cardiac kinase that phosphorylates CREB-Ser(133). This novel Gαq-PKCδ-PKD-CREB pathway contributes to cardiac remodeling and may offer therapeutic targets for heart failure.

Area of Science:

  • Cardiovascular Biology
  • Molecular Signaling
  • Cellular Physiology

Background:

  • cAMP response element-binding protein (CREB) phosphorylation at Ser(133) is crucial for growth regulation.
  • The specific kinases responsible for cardiac CREB-Ser(133) phosphorylation in vivo remain unclear.

Purpose of the Study:

  • To identify the physiologically relevant kinase(s) for CREB-Ser(133) phosphorylation in the heart.
  • To elucidate novel signaling pathways involved in cardiac growth regulation and remodeling.

Main Methods:

  • Utilized cardiomyocytes and cardiac fibroblasts.
  • Employed adenoviral-mediated gene overexpression (PKCδ, PKD1-S744E/S748E).
  • Investigated signaling pathways activated by thrombin, α(1)-adrenergic receptors, epidermal growth factor (EGF), and Pasteurella multocida toxin (PMT).
  • Examined cardiac-specific Gαq overexpression in transgenic mice.

Main Results:

  • Identified Protein Kinase D (PKD) as a novel cardiac CREB-Ser(133) kinase.
  • Demonstrated that thrombin and α(1)-adrenergic receptors activate a PKCδ-PKD pathway leading to CREB-Ser(133) phosphorylation.
  • Showed that PMT and cardiac-specific Gαq overexpression activate the PKD-CREB-Ser(133) pathway, increasing nuclear PKD and phosphorylated CREB, CRE-reporter activity, and Bcl-2 expression.
  • Observed distinct signaling for EGF-induced CREB phosphorylation in cardiac fibroblasts.

Conclusions:

  • A novel Gαq-PKCδ-PKD-CREB-Ser(133) phosphorylation pathway is identified in the heart.
  • This pathway is implicated in cardiomyocyte hypertrophy and cardiac remodeling.
  • Targeting this pathway may offer therapeutic benefits for heart failure phenotypes.

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