Copine 5 (CPNE5)

Copine 5 is a member of the **copine family** of calcium-dependent membrane-binding proteins that contain two N-terminal C2 domains and an integrin A domain-like motif at the C-terminus[2][3][5]. These proteins are involved in **calcium-mediated regulation of intracellular signaling** and membrane trafficking, acting at the interface of the cell membrane and cytoplasm[3][2]. Copine 5 is implicated in processes such as dendrite formation in melanocytes, and enriched expression has been observed in the heart’s conduction system and the lymphatic system[1][2][3]. Variations in the CPNE5 gene have been associated with heart rate variability and arrhythmia in genetic studies[1]. Downregulation of CPNE5 is linked to poorer prognosis in esophageal squamous cell carcinoma, suggesting a disease-modifying or biomarker role but there is no evidence for direct drug targeting or established therapeutic modulation via drugs[4]. No approved drugs or mechanistic drug interactions are reported for CPNE5[3][4]; thus, it is not currently established as a therapeutic target. Low CPNE5 expression is associated with shorter overall survival in esophageal squamous cell carcinoma, making it a potential prognostic biomarker[4]. The protein’s role primarily involves calcium-regulated **membrane and intracellular signaling**, but evidence for receptor, enzyme, transporter, or transcription factor activity is lacking[2][3]. Gene variants and knockout models link CPNE5 to heart conduction and arrhythmia, but again, not as a current therapeutic target[1].

Other names

Copine-5CPNE5KIAA1599CPN5COPN5Copine Vcopine-5copine V