Predicted to enable structural molecule activity. Predicted to be involved in bicellular tight junction assembly and cell adhesion. Predicted to be located in anchoring junction and membrane. Predicted to be active in bicellular tight junction and plasma membrane. Is expressed in eye; female organism; gill; integument; and posterior intestine. Human ortholog(s) of this gene implicated in Crohn's disease and atopic dermatitis. Orthologous to human CLDN1 (claudin 1).