- Na-K-ATPase regulates tight junction permeability through occludin phosphorylation in pancreatic epithelial cells. Rajasekaran, S.A., Barwe, S.P., Gopal, J., Ryazantsev, S., Schneeberger, E.E., Rajasekaran, A.K. Am. J. Physiol. Gastrointest. Liver Physiol. (2007)