@article{DejongheKuenenMylleetal.2016, author = {Dejonghe, Wim and Kuenen, Sabine and Mylle, Evelien and Vasileva, Mina and Keech, Olivier and Viotti, Corrado and Swerts, Jef and Fendrych, Matyas and Ortiz-Morea, Fausto Andres and Mishev, Kiril and Delang, Simon and Scholl, Stefan and Zarza, Xavier and Heilmann, Mareike and Kourelis, Jiorgos and Kasprowicz, Jaroslaw and Nguyen, Le Son Long and Drozdzecki, Andrzej and Van Houtte, Isabelle and Szatmari, Anna-Maria and Majda, Mateusz and Baisa, Gary and Bednarek, Sebastian York and Robert, Stephanie and Audenaert, Dominique and Testerink, Christa and Munnik, Teun and Van Damme, Daniel and Heilmann, Ingo and Schumacher, Karin and Winne, Johan and Friml, Jiri and Verstreken, Patrik and Russinova, Eugenia}, title = {Mitochondrial uncouplers inhibit clathrin-mediated endocytosis largely through cytoplasmic acidification}, series = {Nature Communications}, volume = {7}, journal = {Nature Communications}, publisher = {Nature Publ. Group}, address = {London}, issn = {2041-1723}, doi = {10.1038/ncomms11710}, pages = {1959 -- 1968}, year = {2016}, abstract = {ATP production requires the establishment of an electrochemical proton gradient across the inner mitochondrial membrane. Mitochondrial uncouplers dissipate this proton gradient and disrupt numerous cellular processes, including vesicular trafficking, mainly through energy depletion. Here we show that Endosidin9 (ES9), a novel mitochondrial uncoupler, is a potent inhibitor of clathrin-mediated endocytosis (CME) in different systems and that ES9 induces inhibition of CME not because of its effect on cellular ATP, but rather due to its protonophore activity that leads to cytoplasm acidification. We show that the known tyrosine kinase inhibitor tyrphostinA23, which is routinely used to block CME, displays similar properties, thus questioning its use as a specific inhibitor of cargo recognition by the AP-2 adaptor complex via tyrosine motif-based endocytosis signals. Furthermore, we show that cytoplasm acidification dramatically affects the dynamics and recruitment of clathrin and associated adaptors, and leads to reduction of phosphatidylinositol 4,5-biphosphate from the plasma membrane.}, language = {en} } @article{FrescatadaRosaStanislasBackuesetal.2014, author = {Frescatada-Rosa, Marcia and Stanislas, Thomas and Backues, Steven K. and Reichardt, Ilka and Men, Shuzhen and Boutte, Yohann and Juergens, Gerd and Moritz, Thomas and Bednarek, Sebastian York and Grebe, Markus}, title = {High lipid order of Arabidopsis cell-plate membranes mediated by sterol and Dynamin-Related Protein 1A function}, series = {The plant journal}, volume = {80}, journal = {The plant journal}, number = {5}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0960-7412}, doi = {10.1111/tpj.12674}, pages = {745 -- 757}, year = {2014}, abstract = {Membranes of eukaryotic cells contain high lipid-order sterol-rich domains that are thought to mediate temporal and spatial organization of cellular processes. Sterols are crucial for execution of cytokinesis, the last stage of cell division, in diverse eukaryotes. The cell plate of higher-plant cells is the membrane structure that separates daughter cells during somatic cytokinesis. Cell-plate formation in Arabidopsis relies on sterol- and DYNAMIN-RELATED PROTEIN1A (DRP1A)-dependent endocytosis. However, functional relationships between lipid membrane order or lipid packing and endocytic machinery components during eukaryotic cytokinesis have not been elucidated. Using ratiometric live imaging of lipid order-sensitive fluorescent probes, we show that the cell plate of Arabidopsis thaliana represents a dynamic, high lipid-order membrane domain. The cell-plate lipid order was found to be sensitive to pharmacological and genetic alterations of sterol composition. Sterols co-localize with DRP1A at the cell plate, and DRP1A accumulates in detergent-resistant membrane fractions. Modifications of sterol concentration or composition reduce cell-plate membrane order and affect DRP1A localization. Strikingly, DRP1A function itself is essential for high lipid order at the cell plate. Our findings provide evidence that the cell plate represents a high lipid-order domain, and pave the way to explore potential feedback between lipid order and function of dynamin-related proteins during cytokinesis.}, language = {en} }