کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1931395 | 1050551 | 2010 | 4 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Stimulation of Na+/K+ ATPase activity and Na+ coupled glucose transport by β-catenin Stimulation of Na+/K+ ATPase activity and Na+ coupled glucose transport by β-catenin](/preview/png/1931395.png)
β-Catenin is a multifunctional protein stimulating as oncogenic transcription factor several genes important for cell proliferation. β-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 β-catenin influences membrane transport. To this end, β-catenin was expressed in Xenopus oocytes with or without SGLT1 and electrogenic transport determined by dual electrode voltage clamp. As a result, expression of β-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 β-catenin on the endogenous Na+/K+-ATPase was not due to enhanced stability of the pump protein in the cell membrane. Expression of β-catenin further enhanced glucose-induced current (Ig) in SGLT1-expressing oocytes. In the absence of SGLT1 Ig was negligible irrespective of β-catenin expression. The stimulating effect of β-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 β-catenin, i.e. the regulation of transport.
Research highlights
► The oncogenic transcription factor β-catenin stimulates the Na+/K+-ATPase.
► β-Catenin stimulates SGLT1 dependent Na+, glucose cotransport.
► The effects are independent of transcription.
► β-Catenin sensitive transport may contribute to properties of proliferating cells.
Journal: Biochemical and Biophysical Research Communications - Volume 402, Issue 3, 19 November 2010, Pages 467–470