Claudin-4 forms paracellular chloride channel in the kidney and requires claudin-8 for tight junction localization

• DOI: 10.1073/pnas.1009399107
• Publication Date: 2010-10-05T02:41:48Z
• Authors: Jianghui Hou; Aparna Renigunta; Jing Yang; Siegfried Waldegger
• Keywords: Paracellular transport; Claudin; Homeostasis

Tight junctions (TJs) play a key role in mediating paracellular ion reabsorption the kidney. The pathway collecting duct of kidney is predominant route for transepithelial chloride that determines extracellular NaCl content and blood pressure. However, molecular mechanisms underlying are not understood. Here we showed mouse cells, claudin-4 functioned as Cl – channel. A positively charged lysine residue at position 65 was critical its anion selectivity. Claudin-4 observed to interact with claudin-8 using several criteria. In assembly into TJ strands required interaction claudin-8. Depletion resulted loss conductance, through mechanism involving recruitment during assembly. Together, our data show interacts their association anion-selective duct, suggesting coupling sodium duct.