PKN1

PKN1 Full Name

protein kinase N1

PKN1 Introduction

Protein kinase N1 (PKN1), also historically known as PRK1, is a highly conserved serine/threonine-protein kinase belonging to the protein kinase C (PKC) superfamily. Structurally characterized by an N-terminal Rho-binding domain, PKN1 functions as a major downstream effector for small Rho family GTPases, specifically RhoA and Rac1. Upon activation by these GTPases or lipid second messengers like arachidonic acid, PKN1 translocates to specific subcellular compartments where it actively phosphorylates a broad array of cytoskeletal targets. Physiologically, PKN1 is an essential master regulator of actin cytoskeleton remodeling, cell adhesion, and vesicle trafficking. In the central nervous system, PKN1 is critical for neurodevelopment; it intricately orchestrates the maturation of dendritic spines and the formation of healthy synapses, ensuring robust neural connectivity and synaptic plasticity.

Figure 1. Activation of PKNs. (Source: Marrocco V, et al. 2019)

The clinical significance of PKN1 is most prominently highlighted in highly aggressive, hormone-driven malignancies, particularly prostate cancer. In the tumor microenvironment, PKN1 is frequently overexpressed and acts as a potent oncogenic signaling hub. By hyperactivating androgen receptor (AR) signaling and drastically altering the cancer cell's actin cytoskeleton, PKN1 equips prostate cancer cells with enhanced migratory and invasive capabilities. This cytoskeletal plasticity allows malignant cells to efficiently break through basement membranes, driving fatal distant metastasis. Furthermore, elevated PKN1 activity strongly correlates with advanced tumor grades and resistance to standard androgen-deprivation therapies. Because of its pivotal structural role in facilitating cancer cell motility and survival, targeted pharmacological inhibition of the PKN1 signaling axis is rapidly emerging as a promising therapeutic strategy to halt cancer metastasis and overcome therapy resistance.

Alternate Names for PKN1

PKN1; protein kinase N1; serine/threonine-protein kinase N1; protein kinase PKN; protein kinase C-like 1; protein kinase C-like PKN; protease-activated kinase 1; protein-kinase C-related kinase 1; serine-threonine protein kinase N; PAK-1; Prkcl1;

• 1. Wang X, et al. Protein kinase N1 promotes proliferation and invasion of liver cancer. Exp Ther Med. 2021 Jun;21(6):651.
  2. Marrocco V, et al. PKC and PKN in heart disease. J Mol Cell Cardiol. 2019 Mar;128:212-226.