epsilon-V1-2, PKCe Inhibitor

Product Name: epsilon-V1-2, PKCe Inhibitor

Sequence One Letter Code: EAVSLKPT

Sequence Three Letter Code: H-Glu-Ala-Val-Ser-Leu-Lys-Pro-Thr-OH

Chemical Formula:C37H65N9O13

Molecular Weight: 844

Purity: 95%

Form: Lyophilized

Storage Conditions: - 20 °C

Research Area: Cancer Disease Research

Source / Species: Human, mouse, rat, bovine

Conjugation: Unconjugated

Code Nacres: NA.26

Application: εV1-2 is a selective inhibitory peptide derived from residues 14–21 of the C2 domain of protein kinase C epsilon (PKCε). It disrupts the interaction between PKCε and its receptor for activated C kinase (RACK2), selectively blocking PKCε signaling without affecting other PKC isoforms. PKCε regulates processes including cell proliferation, differentiation, survival, and stress responses. This peptide is widely used to dissect isoform-specific PKC signaling pathways and to evaluate PKCε function in cardiovascular biology, cancer progression, and ischemic preconditioning. It provides a targeted approach for studying PKCε-dependent cellular mechanisms.

Current Research: Protein kinase C epsilon (PKCε) is a member of the novel PKC (nPKC) subfamily and plays a central role in regulating signal transduction pathways that govern cell proliferation, differentiation, survival, migration, and stress adaptation. Unlike conventional PKC isoforms, PKCε is activated by diacylglycerol (DAG) but is calcium-independent. Its spatial and temporal specificity is determined not only by catalytic activation but also by subcellular targeting through interaction with scaffolding proteins known as receptors for activated C kinase (RACKs). Among these, RACK2 (also known as β′-COP) mediates PKCε translocation to defined intracellular compartments where it phosphorylates context-specific substrates. εV1-2 is a selective inhibitory peptide derived from residues 14–21 of the C2 domain of PKCε. This short sequence corresponds to a region critical for binding to RACK2. By mimicking the native interaction interface, εV1-2 competitively disrupts PKCε–RACK2 association, thereby preventing proper subcellular localization and downstream signaling. Importantly, because the sequence is unique to PKCε, the peptide selectively blocks PKCε activity without inhibiting other PKC isoforms. This isoform specificity distinguishes εV1-2 from small-molecule PKC inhibitors, which often lack selectivity and affect multiple PKC family members. The mechanism of εV1-2 is based on interference with protein–protein interactions rather than direct catalytic inhibition. PKC isoforms require anchoring to RACK proteins following activation to achieve substrate specificity. By preventing PKCε translocation, εV1-2 effectively suppresses phosphorylation of PKCε-specific substrates while preserving signaling mediated by PKCα, PKCδ, and other isoforms. This property has made εV1-2 an essential tool for dissecting isoform-resolved PKC signaling networks in complex cellular systems. In cardiovascular research, PKCε has been extensively studied for its role in ischemic preconditioning (IPC), a protective phenomenon in which brief episodes of ischemia render the myocardium resistant to subsequent prolonged ischemic injury. Activation and mitochondrial translocation of PKCε are key steps in IPC-mediated cardioprotection, influencing mitochondrial permeability transition pore regulation, reactive oxygen species signaling, and prosurvival kinase cascades. Application of εV1-2 in experimental models abolishes the protective effects of preconditioning, demonstrating that PKCε signaling is necessary for cardioprotective adaptation. This selective inhibition has clarified the mechanistic distinction between PKCε and other PKC isoforms in myocardial stress responses. In oncology, PKCε functions as an oncogenic kinase in multiple tumor types, including breast, prostate, and lung cancers. It promotes cell survival, enhances proliferation, supports epithelial–mesenchymal transition (EMT), and contributes to metastatic progression. Overexpression of PKCε correlates with poor prognosis and aggressive phenotypes. εV1-2 has been employed in cancer cell models to delineate PKCε-dependent signaling pathways, including modulation of Akt, STAT3, and MAPK cascades. By selectively blocking PKCε anchoring and downstream phosphorylation events, researchers can assess its contribution to tumor growth and resistance to apoptosis. Beyond cardiovascular and cancer biology, PKCε regulates cytoskeletal dynamics, vesicular trafficking, and inflammatory signaling. In neuronal systems, PKCε participates in synaptic plasticity and nociceptive sensitization. In immune cells, it modulates cytokine production and stress-activated pathways. εV1-2 enables precise interrogation of these processes by providing acute and reversible inhibition of PKCε without genetic manipulation. When conjugated to cell-penetrating sequences, the peptide can be delivered intracellularly to modulate signaling in vitro and in vivo. A key advantage of εV1-2 lies in its ability to differentiate catalytic activity from localization-dependent signaling. Because PKC function depends heavily on spatial targeting, disruption of RACK binding reveals how compartmentalization governs substrate selection and biological outcome. This has advanced understanding of PKC isoform specificity, a longstanding challenge in kinase biology. In summary, εV1-2 is a selective peptide inhibitor derived from the C2 domain of PKCε that disrupts PKCε–RACK2 interactions and prevents isoform-specific signaling. By targeting protein–protein interactions rather than ATP binding, it provides high specificity and functional resolution. Widely used in studies of cardiovascular protection, cancer progression, and stress signaling, εV1-2 remains a powerful molecular tool for elucidating PKCε-dependent cellular mechanisms and refining therapeutic strategies aimed at isoform-selective kinase modulation.