Molecular organization and function of vertebrate septate-like junctions

Catherine Faivre-Sarrailh (1)

1 INMED - INSERM U1249 - Institut de Neurobiologie de la Méditerranée [Aix-Marseille Université]

Septate-like junctions display characteristic ladder-like ultrastructure reminiscent of the invertebrate epithelial septate junctions and are present at the paranodes of myelinated axons. The paranodal junctions where the myelin loops attach to the axon at the borders of the node of Ranvier provide both a paracellular barrier to ion diffusion and a lateral fence along the axonal membrane. The septate-like junctions constrain the proper distribution of nodal Na+ channels and juxtaparanodal K+ channels, which are required for the safe propagation of the nerve influx and rapid saltatory conduction. The paranodal cell adhesion molecules have been identified as target antigens in peripheral demyelinating autoimmune diseases and the pathogenic mechanisms described. This review aims at presenting the recent knowledge on the molecular and structural organization of septate-like junctions, their formation and stabilization during development, and how they are involved in demyelinating diseases.

Mots clés: Myelin; Node of Ranvier; Paranodal junctions; Caspr; Contactin; Neurofascin

Domaines: Biologie cellulaire

Catherine Faivre-Sarrailh. Molecular organization and function of vertebrate septate-like junctions. Biochimica et Biophysica Acta:Biomembranes, 2020, 1862 (5), pp.183211. ⟨10.1016/j.bbamem.2020.183211⟩. ⟨hal-02509064⟩