Enables protein C-terminus binding activity. Involved in several processes, including cellular response to glucose stimulus; negative regulation of vascular permeability; and response to lipopolysaccharide. Located in bicellular tight junction; cytoplasm; and gap junction. Biomarker of several diseases, including brain ischemia; cholestasis; peptic esophagitis; perinatal necrotizing enterocolitis; and uveitis. Orthologous to human TJP1 (tight junction protein 1). [provided by Alliance of Genome Resources, Apr 2022]