@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} } @misc{CoxMarisSoetartetal.2009, author = {Cox, Tom and Maris, Tom and Soetart, Karline and Conley, Daniel and van Damme, Stefan and Meire, Patrick and Middelburg, Jack J. and Vos, Matthijs and Struyf, Eric}, title = {A macro-tidal freshwater ecosystem recovering from hypereutrophication : the Schelde lease study}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-45180}, year = {2009}, abstract = {We report a 40 year record of eutrophication and hypoxia on an estuarine ecosystem and its recovery from hypereutrophication. After decades of high inorganic nutrient concentrations and recurring anoxia and hypoxia, we observe a paradoxical increase in chlorophyll-a concentrations with decreasing nutrient inputs. We hypothesise that algal growth was inhibited due to hypereutrophication, either by elevated ammonium concentrations, severe hypoxia or the production of harmful substances in such a reduced environment. We study the dynamics of a simple but realistic mathematical model, incorporating the assumption of algal growth inhibition. It shows a high algal biomass, net oxygen production equilibrium with low ammonia inputs, and a low algal biomass, net oxygen consumption equilibrium with high ammonia inputs. At intermediate ammonia inputs it displays two alternative stable states. Although not intentional, the numerical output of this model corresponds to observations, giving extra support for assumption of algal growth inhibition. Due to potential algal growth inhibition, the recovery of hypereutrophied systems towards a classical eutrophied state, will need reduction of waste loads below certain thresholds and will be accompanied by large fluctuations in oxygen concentrations. We conclude that also flow-through systems, heavily influenced by external forcings which partly mask internal system dynamics, can display multiple stable states.}, language = {en} }