Fig. 8. A model for CeAJ assembly and composition in the epidermis. Cartoons showing the localisation of HMP-1 (blue), JAM-1 (green), DLG-1 (red) and LET-413 (purple) proteins in epidermal cells. (A) An immature wild-type cell showing that HMP-1 and DLG-1/JAM-1 exhibit a mutually exclusive distribution along the lateral membrane. (B) A mature wild-type cell illustrating a compact subapical junction consisting of a JAM-1/DLG-1 unit associated with the electron-dense component, and a HMP-1 unit, which is generally localised more apically than JAM-1/DLG-1 and is always distinct. Arrows from the CeAJ domains indicate their possible functions. (C) A LET-413-deficient cell showing mislocalisation of CeAJ proteins. This suggests that LET-413 plays a role in compacting and positioning CeAJ components to form mature CeAJs. (D) A DLG-1-deficient cell, showing that JAM-1 exhibits a discontinuous pattern around the cell and is mislocalised slightly further basally where present. The electron-dense CeAJ component is also missing in these cells, which suggests that DLG-1 aggregates JAM-1 and other proteins at the CeAJ.
