Contactin-associated protein 1 (CNTNAP1)

Contactin-associated protein 1 (CNTNAP1, also called CASPR or Paranodin) is a critical neuronal cell adhesion molecule and a key member of the neurexin family[3]. It is a large transmembrane protein, highly concentrated at the paranodal regions of myelinated axons, where it forms multiprotein complexes with contactin (a GPI-anchored protein) and neurofascin 155 on glial cells[2][3]. CNTNAP1 acts as a molecular scaffold that organizes and stabilizes the paranodal junctions, keeping sodium and potassium channels in their proper axonal domains and thus enabling rapid and efficient saltatory nerve conduction[1][2][3]. Its extracellular domain contains various protein-protein interaction modules, while its cytoplasmic tail links the complex to the axonal cytoskeleton[2]. CNTNAP1 is essential for neurodevelopment, particularly in coordinating the timing of neuron versus astrocyte differentiation[2]. Mutations in CNTNAP1 result in a range of severe congenital neuropathies, reflecting its indispensable role in nervous system structure and function[1][3]. There are no current drugs known to directly target CNTNAP1, but its disruption has been linked to diseases such as congenital hypomyelinating neuropathy and severe neurodevelopmental disabilities[3].

Other names

CASPRParanodinNRXN4Caspr1p190Neurexin IVNeurexin-4CHN3