Ankyrin-3 (ANK3)

Ankyrin-3 (ANK3), also known as ankyrin-G, is a large multi-domain scaffold protein of the ankyrin family, distinct from ankyrin-1 and ankyrin-2[1][2][3]. Ankyrin-3 is immunologically unique and is most prominently localized at the axon initial segment and nodes of Ranvier in neurons, where it orchestrates the clustering of voltage-gated sodium channels, cell adhesion molecules (e.g., neurofascin186), and spectrin-based cytoskeletal complexes[1][2][3][4][6]. This role is essential for establishing and maintaining neuronal polarity and facilitating rapid propagation of action potentials in myelinated axons[1][2][4][6]. In non-neuronal tissues (e.g., cardiac muscle, epithelia), ankyrin-3 contributes to the organization and stabilization of membrane microdomains, regulating the localization of ion channels (e.g., Na_v1.5 in the heart) and cell–cell adhesion machinery[2][3]. Disruption or mutation of ANK3 is associated with a spectrum of neuropsychiatric disorders (notably bipolar disorder), intellectual disability, autism spectrum disorder, and certain cardiac arrhythmias, particularly Brugada syndrome, where loss of interaction with cardiac sodium channels disrupts their surface expression[2][5]. Despite its pivotal role in cell organization and disease association, ankyrin-3 is not a classical therapeutic target (not a receptor, enzyme, transporter, or ion channel), and to date, there are no approved drugs that directly target ANK3 protein function[2][3][5]. Detection of ANK3 genetic variants or altered expression may have utility as biomarkers in risk prediction or diagnostic panels, especially for neuropsychiatric and neurodevelopmental disorders[5].

Other names

Ankyrin-GAnkyrin 3ankyrin-3node of Ranvier (ankyrin G)ANKYRIN-GMRT37node of Ranvier