PRKCE

PRKCE Full Name

protein kinase C, epsilon

PRKCE Introduction

Protein kinase C epsilon (PRKCE, or PKCε) is a prominent and highly versatile member of the "novel" protein kinase C (nPKC) subfamily. Similar to other novel PKCs, its enzymatic activation is driven by diacylglycerol (DAG) and specific membrane phospholipids (such as phosphatidylserine), but it functions entirely independent of calcium. Upon activation, PRKCE translocates from the cytosol to distinct subcellular compartments—including the plasma membrane, Golgi network, and mitochondria—guided by specific anchoring proteins known as RACKs (Receptors for Activated C-Kinase). This precise spatial targeting allows PRKCE to selectively phosphorylate a wide array of downstream substrates, establishing it as a pivotal signaling hub across various fundamental cellular processes.

Figure 1. Protein kinase C peptide modulators. (Source: Palaniyandi SS, et al. 2009)

Physiologically, PRKCE is highly expressed in the nervous system and the heart. In the central and peripheral nervous systems, it finely modulates neurotransmitter release, ion channel activity, and synaptic plasticity. It is particularly renowned for its critical role in nociception, where it actively sensitizes primary sensory neurons and acts as a primary mediator of inflammatory hyperalgesia (enhanced pain sensitivity). In the cardiovascular system, PRKCE serves as the central molecular effector of ischemic preconditioning. This is a potent, endogenous cardioprotective mechanism where brief, non-lethal periods of ischemia protect the myocardium against subsequent, massive ischemic damage by stabilizing mitochondrial function and preventing cardiac apoptosis.

However, because of its potent pro-survival and mitogenic properties, the chronic dysregulation of PRKCE is heavily implicated in severe human pathologies, most notably cancer. In stark contrast to other isoforms (like PRKCD) that can act as tumor suppressors, PRKCE is widely recognized as a bona fide transforming oncogene. Its aberrant overexpression is frequently observed in numerous aggressive malignancies, including prostate, breast, lung, and head and neck squamous cell carcinomas. In these oncological contexts, elevated PRKCE signaling promotes unchecked tumor cell proliferation, aggressively inhibits apoptosis, enhances cellular motility, and drives metastasis. Furthermore, elevated PRKCE activity is strongly linked to alcohol addiction and anxiety disorders due to its regulation of GABA_A receptors. Consequently, developing highly specific PRKCE inhibitors remains a major priority for targeted cancer therapies and chronic pain management.

Alternate Names for PRKCE

PRKCE; protein kinase C, epsilon; Pkce; PKC[e]; R75156; PKCepsilon; 5830406C15Rik; protein kinase C epsilon type; nPKC-epsilon;

• 1. Palaniyandi SS, et al. Protein kinase C in heart failure: a therapeutic target? Cardiovasc Res. 2009 May 1;82(2):229-39.
  2. Gorin MA, et al. Protein kinase C epsilon: an oncogene and emerging tumor biomarker. Mol Cancer. 2009 Feb 19;8:9.