[摘要]：beta-Catenin is a multifunctional protein stimulating as oncogenic transcription factor several genes important for cell proliferation beta-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 beta-catenin influences membrane transport To this end, beta-catenin was expressed in Xenopus oocytes with or without SGLT1 and electrogenic transport determined by dual electrode voltage clamp As a result, expression of beta-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 beta-catenin on the endogenous Na+/K+-ATPase was not due to enhanced stability of the pump protein in the cell membrane Expression of beta-catenin further enhanced glucose-induced current (Ig) in SGLT1-expressing oocytes. In the absence of SGLT1 Ig was negligible irrespective of beta-catenin expression The stimulating effect of beta-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 beta-catenin. i e the regulation of transport (C) 2010 Elsevier Inc All rights reserved
