Serine/threonine-protein kinase N1

PKN1 (serine/threonine-protein kinase N1) is a PKC-related kinase that regulates the actin cytoskeleton, cell migration, and transcriptional processes through phosphorylation of diverse substrates (UniProt: Q16512). It participates in adrenergic signaling cascades involving ADRA1B and MAPK14, and modulates cytoskeletal dynamics by phosphorylating intermediate filament proteins including vimentin and neurofilaments. Notably, PKN1 phosphorylates tau protein (MAPT) at multiple sites, reducing its microtubule-binding capacity and disrupting tubulin assembly.

PKN1 also functions as a coactivator of androgen receptor-dependent transcription through histone H3 phosphorylation and regulates histone deacetylases, playing broader roles in chromatin remodeling and gene expression. The kinase phosphorylates GFAP and MARCKS, linking it to cytoskeletal and signaling networks in neural contexts.

In Alzheimer's disease, PKN1 is upregulated in post-mortem AD brain tissue compared to age-matched controls (mean log2FC = 0.46, Chaparral AD proteomics), suggesting elevated kinase activity in disease pathology. Given PKN1's documented role in tau phosphorylation and cytoskeletal disruption, this upregulation may contribute to tau pathology and neuronal cytoskeletal dysfunction characteristic of AD.