caa a22 4500 475771656 CHVBK 20180406123619.0 cr unu---uuuuu 170329e20001101xx s 000 0 eng 10.1007/s001250051563 doi (NATIONALLICENCE)springer-10.1007/s001250051563 Rab11 is associated with GLUT4-containing vesicles and redistributes in response to insulin [Elektronische Daten] [A. Kessler, E. Tomas, D. Immler, H. E. Meyer, A. Zorzano, J. Eckel] Abstract : Aims/hypothesis. To identify a GTPase of 24 000 Mr which we recently found to co-localize with GLUT4 in cardiac muscle. Methods. A 24 000 Mr-GTP-binding fraction was purified from pig heart by a three-step chromatographic procedure, followed by two-dimensional electrophoresis and electrospray ionization-mass spectrometry. Subcellular distribution of the GTPase was assessed by western blotting. Co-localization with GLUT4 was assessed by continuous sucrose density gradient fractionation and immunoadsorption of GLUT4-containing vesicles. Results. The Rab11 protein was identified as a major component of the GTP-binding fraction and its expression in rat cardiac muscle was confirmed. In vivo insulin treatment resulted in the recruitment of Rab11 from the microsomal fraction to the plasma membrane. Subcellular fractionation indicated two immunoreactive GLUT4 pools. Most of the intracellular pool of Rab11 overlapped with the high-density GLUT4 pool and most of the transferrin receptor pool. The Rab11 protein also co-sedimented with the low-density, non-endosomal GLUT4 pool and substantially increased in this fraction after insulin treatment. It was specifically present in GLUT4-containing vesicles and insulin increased its abundance in these vesicles 2.2-fold relative to the amount of GLUT4. These vesicles also containend Rab4 and Akt-2, the latter being only associated after insulin stimulation. Insulin was unable to alter the cellular localization of Rab11 in insulin-resistant obese Zucker rats. Conclusion/interpretation. These results support the hypothesis that at least two GTPases of the Rab family participate in GLUT4-vesicle trafficking. We suggest that Rab11 is involved in the endosomal recycling, sorting and exocytotic movement of the glucose transporter. [Diabetologia (2000) 43: 1518-1527] Springer-Verlag Berlin Heidelberg, 2000 Keywords GLUT4 trafficking nationallicence Rab11 nationallicence cardiac muscle nationallicence GLUT4-containing vesicles nationallicence small GTP-binding proteins nationallicence Zucker rats nationallicence Kessler A. Molecular Cardiology, Diabetes Research Institute, Düsseldorf, Germany, DE aut Tomas E. Department of Biochemistry and Molecular Biology, University of Barcelona, Barcelona, Spain, ES aut Immler D. Institute for Physiological Chemistry, Ruhr University Bochum, Bochum, Germany, DE aut Meyer H. E. Institute for Physiological Chemistry, Ruhr University Bochum, Bochum, Germany, DE aut Zorzano A. Department of Biochemistry and Molecular Biology, University of Barcelona, Barcelona, Spain, ES aut Eckel J. Molecular Cardiology, Diabetes Research Institute, Düsseldorf, Germany, DE aut https://doi.org/10.1007/s001250051563 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s001250051563 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kessler A. Molecular Cardiology, Diabetes Research Institute, Düsseldorf, Germany, DE aut NATIONALLICENCE 700 1- Tomas E. Department of Biochemistry and Molecular Biology, University of Barcelona, Barcelona, Spain, ES aut NATIONALLICENCE 700 1- Immler D. Institute for Physiological Chemistry, Ruhr University Bochum, Bochum, Germany, DE aut NATIONALLICENCE 700 1- Meyer H. E. Institute for Physiological Chemistry, Ruhr University Bochum, Bochum, Germany, DE aut NATIONALLICENCE 700 1- Zorzano A. Department of Biochemistry and Molecular Biology, University of Barcelona, Barcelona, Spain, ES aut NATIONALLICENCE 700 1- Eckel J. Molecular Cardiology, Diabetes Research Institute, Düsseldorf, Germany, DE aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer