Death-associated protein kinase 1 phosphorylates NDRG2 and induces neuronal cell death

Area of Science:

• Neuroscience
• Molecular Biology
• Cell Biology

Background:

• Death-associated protein kinase 1 (DAPK1) is linked to neuronal cell death and diseases like Alzheimer's disease (AD).
• The precise molecular mechanisms of DAPK1 in signaling neuronal cell death remain largely unexplored.

Purpose of the Study:

• To identify novel substrates of DAPK1 involved in neuronal cell death.
• To elucidate the role of DAPK1-mediated phosphorylation in regulating neuronal cell death and its relevance to Alzheimer's disease.

Main Methods:

• Phospho-peptide library screening to identify DAPK1 substrates.
• In vitro and in vivo experiments to confirm DAPK1 interaction and phosphorylation of NDRG2 at Ser350.
• Utilized DAPK1 inhibition and ablation models, including Tg2576 AD mouse models, and analyzed human AD brain samples.

Main Results:

• N-myc downstream-regulated gene 2 (NDRG2) was identified as a novel DAPK1 substrate, phosphorylated at Ser350.
• DAPK1 overexpression enhanced ceramide-induced neuronal cell death via NDRG2 phosphorylation, while DAPK1 inhibition reduced cell death and NDRG2 phosphorylation.
• DAPK1 ablation protected against cell death in mouse models of AD, and elevated phosphorylated NDRG2 Ser350 and DAPK1 levels were observed in human AD brains.

Conclusions:

• Phosphorylation of NDRG2 at Ser350 by DAPK1 is a novel mechanism that activates NDRG2 function and drives neuronal cell death.
• This DAPK1-NDRG2 pathway plays a significant role in vivo, contributing to neuronal cell death and potentially Alzheimer's disease pathology.