@b-Catenin is a multifunctional protein stimulating as oncogenic transcription factor several genes important for cell proliferation. @b-Catenin-regulated genes include the serum- and glucocorticoid-inducible kinase SGK1, which is known to stimulate a variety of transport systems. The present study explored the possibility that @b-catenin influences membrane transport. To this end, @b-catenin was expressed in Xenopus oocytes with or without SGLT1 and electrogenic transport determined by dual electrode voltage clamp. As a result, expression of @b-catenin significantly enhanced the ouabain-sensitive current of the endogeneous Na^+/K^+-ATPase. Inhibition of vesicle trafficking by brefeldin A revealed that the stimulatory effect of @b-catenin on the endogenous Na^+/K^+-ATPase was not due to enhanced stability of the pump protein in the cell membrane. Expression of @b-catenin further enhanced glucose-induced current (Ig) in SGLT1-expressing oocytes. In the absence of SGLT1 Ig was negligible irrespective of @b-catenin expression. The stimulating effect of @b-catenin on both Na^+/K^+ ATPase and SGLT1 activity was observed even in the presence of actinomycin D, an inhibitor of transcription. The experiments disclose a completely novel function of @b-catenin, i.e. the regulation of transport.