%0 Generic %A Markgraf, Daniel Frank %D 2008 %F heidok:8904 %K RabGTPase , Tethering FaktorenVesicular transport , RabGTPase , Tethering factor %R 10.11588/heidok.00008904 %T The Role of Rab GTPases in the Endolysosomal System of S.cerevisiae %U https://archiv.ub.uni-heidelberg.de/volltextserver/8904/ %X The evolution of the eucaryotic cell was accompanied by the development of an elaborate endomembrane system. Transport between intracellular compartments is mediated by vesicular carriers that constantly bud from donor membranes and fuse with target compartments. RabGTPases together with tethering factors mediate first specific contact between membranes destined fusion. This study focuses on the interplay between the endosomal RabGTPase Vps21 and the endosomal tethering complex, CORVET. The CORVET subunit Vps8 is the direct effector subunit and mediates binding to the GTP-form of Vps21, whereas the subunit Vps3 binds the GDP-form of Vps21. Vps8 and Vps21 functionally interact to mediate late endosomal tethering events. Furthermore, Vps8 and Vps21, together with the two other CORVET subunits, Vps3 and Vps16 were shown to be the minimal molecular requirement for late endosomal tethering.The results presented here indicate that the sequential recruitment of Vps8 to Vps21-positive late endosomes initiates tethering and leads to further assembly of the CORVET complex that dictates successive fusion events.