caa a22 4500 463254198 CHVBK 20180405153349.0 cr unu---uuuuu 170326e20070901xx s 000 0 eng 10.1007/s10571-007-9176-7 doi (NATIONALLICENCE)springer-10.1007/s10571-007-9176-7 Pituicyte Stellation is Prevented by RhoA-or Cdc42-Dependent Actin Polymerization [Elektronische Daten] [Lia Rosso, Patricia Pierson, Claire Golfier, Brigitta Peteri-Brunbäck, Christophe Deroanne, Ellen Van Obberghen-Schilling, Jean-Marc Mienville] Our aim was to shed light on different steps leading from metabotropic receptor activation to changes in cell shape, such as those that characterize the morphological plasticity of neurohypophysial astrocytes (pituicytes). Using explant cultures of adult rat pituicytes, we have previously established that adenosine A1 receptor activation induces stellation via inhibition of RhoA monomeric GTPase and subsequent disruption of actin stress fibers. Here, we rule out RhoA phosphorylation as a mechanism for that inhibition. Rather, our results are more consistent with involvement of a GTPase-activating protein (GAP). siRNA and pull-down experiments suggest that a step downstream of RhoA might involve Cdc42, another GTPase of the Rho family. However, RhoA activation, e.g., in the presence of serum, induces stress fibers, whereas direct Cdc42 activation appears to confine actin within a submembrane—i.e., cortical—network, which also prevents stellation. Therefore, we propose that RhoA may activate Cdc42 in parallel with an effector, such as p160Rho-kinase, that induces and maintains actin stress fibers in a dominant fashion. Rac1 is not involved in the stellation process per se but appears to induce a dendritogenic effect. Ultimately, it may be stated that pituicyte stellation is inducible upon mere actin depolymerization, and preventable upon actin organization, be it in the form of stress fibers or in a cortical configuration. Springer Science+Business Media, LLC, 2007 Neurohypophysis nationallicence Small GTPases nationallicence Stress fibers nationallicence Cortical actin nationallicence Adenosine nationallicence Rosso Lia CNRS UMR 6548, Laboratoire de Physiologie Cellulaire et Moléculaire Faculté des Sciences, Université de Nice-Sophia Antipolis, 28 Avenue Valrose, 06108, Nice Cedex 2, France aut Pierson Patricia CNRS UMR 6548, Laboratoire de Physiologie Cellulaire et Moléculaire Faculté des Sciences, Université de Nice-Sophia Antipolis, 28 Avenue Valrose, 06108, Nice Cedex 2, France aut Golfier Claire CNRS UMR 6548, Laboratoire de Physiologie Cellulaire et Moléculaire Faculté des Sciences, Université de Nice-Sophia Antipolis, 28 Avenue Valrose, 06108, Nice Cedex 2, France aut Peteri-Brunbäck Brigitta CNRS UMR 6548, Laboratoire de Physiologie Cellulaire et Moléculaire Faculté des Sciences, Université de Nice-Sophia Antipolis, 28 Avenue Valrose, 06108, Nice Cedex 2, France aut Deroanne Christophe CNRS UMR 6543, Centre Antoine Lacassagne, Université de Nice-Sophia Antipolis, Nice, France aut Van Obberghen-Schilling Ellen CNRS UMR 6543, Centre Antoine Lacassagne, Université de Nice-Sophia Antipolis, Nice, France aut Mienville Jean-Marc CNRS UMR 6548, Laboratoire de Physiologie Cellulaire et Moléculaire Faculté des Sciences, Université de Nice-Sophia Antipolis, 28 Avenue Valrose, 06108, Nice Cedex 2, France aut Cellular and Molecular Neurobiology Springer US; http://www.springer-ny.com 27/6(2007-09-01), 791-804 0272-4340 27:6<791 2007 27 10571 https://doi.org/10.1007/s10571-007-9176-7 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10571-007-9176-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Rosso Lia CNRS UMR 6548, Laboratoire de Physiologie Cellulaire et Moléculaire Faculté des Sciences, Université de Nice-Sophia Antipolis, 28 Avenue Valrose, 06108, Nice Cedex 2, France aut NATIONALLICENCE 700 1- Pierson Patricia CNRS UMR 6548, Laboratoire de Physiologie Cellulaire et Moléculaire Faculté des Sciences, Université de Nice-Sophia Antipolis, 28 Avenue Valrose, 06108, Nice Cedex 2, France aut NATIONALLICENCE 700 1- Golfier Claire CNRS UMR 6548, Laboratoire de Physiologie Cellulaire et Moléculaire Faculté des Sciences, Université de Nice-Sophia Antipolis, 28 Avenue Valrose, 06108, Nice Cedex 2, France aut NATIONALLICENCE 700 1- Peteri-Brunbäck Brigitta CNRS UMR 6548, Laboratoire de Physiologie Cellulaire et Moléculaire Faculté des Sciences, Université de Nice-Sophia Antipolis, 28 Avenue Valrose, 06108, Nice Cedex 2, France aut NATIONALLICENCE 700 1- Deroanne Christophe CNRS UMR 6543, Centre Antoine Lacassagne, Université de Nice-Sophia Antipolis, Nice, France aut NATIONALLICENCE 700 1- Van Obberghen-Schilling Ellen CNRS UMR 6543, Centre Antoine Lacassagne, Université de Nice-Sophia Antipolis, Nice, France aut NATIONALLICENCE 700 1- Mienville Jean-Marc CNRS UMR 6548, Laboratoire de Physiologie Cellulaire et Moléculaire Faculté des Sciences, Université de Nice-Sophia Antipolis, 28 Avenue Valrose, 06108, Nice Cedex 2, France aut NATIONALLICENCE 773 0- Cellular and Molecular Neurobiology Springer US; http://www.springer-ny.com 27/6(2007-09-01), 791-804 0272-4340 27:6<791 2007 27 10571 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer