Regulation of protein kinase D1 activity

Area of Science:

• Molecular Biology
• Cell Signaling
• Biochemistry

Background:

• Protein kinase D1 (PKD1) is a stress-activated kinase regulating cell growth, apoptosis, adhesion, motility, and angiogenesis.
• Dysregulated PKD1 is implicated in cancer and cardiovascular disease pathogenesis.
• Canonical PKD1 activation involves G protein-coupled receptors and peptide growth factors, leading to diacylglycerol accumulation and protein kinase C (PKC)-dependent phosphorylation.

Purpose of the Study:

• To review the complex multisite phosphorylations of PKD1.
• To explore how these modifications influence PKD1 catalytic activity, scaffold interactions, and subcellular localization.
• To highlight novel therapeutic targets for PKD1-directed pharmaceuticals.

Main Methods:

• Literature review of existing studies on PKD1 activation and regulation.
• Analysis of phosphorylation sites, including activation loop and C-terminal residues.
• Discussion of autophosphorylation and trans-phosphorylation events.

Main Results:

• PKD1 activation involves PKC-dependent phosphorylation at conserved serine residues in the activation loop, enhancing catalytic activity.
• Additional phosphorylation events, including autophosphorylation and trans-phosphorylation, contribute to spatiotemporal control of PKD1 signaling.
• Multisite phosphorylations affect PKD1's catalytic activity, docking interactions, and trafficking to specific cellular compartments.

Conclusions:

• PKD1 regulation is more complex than previously understood, involving intricate multisite phosphorylation patterns.
• These phosphorylation events are critical for controlling PKD1 signaling dynamics and localization.
• Targeting PKD1 phosphorylation represents a promising strategy for developing novel therapeutics for cancer and cardiovascular diseases.