|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
First published online 17 July 2007
doi: 10.1242/jcs.03475
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Research Article |
European Neuroscience Institute-Göttingen, Cell Biophysics Group and DFG Research Center for Molecular Physiology of the Brain (CMPB), D-37073 Göttingen, Germany
* Author for correspondence (e-mail: fwouter{at}gwdg.de)
Accepted 24 May 2007
NGF-induced differentiation of PC12 cells is mediated by actin-polymerisation-driven membrane protrusion, involving GTPase signalling pathways that activate actin nucleation promoting factors such as the neural Wiskott-Aldrich syndrome protein (N-WASP). Expression of the exocyst subunit Exo70 in PC12 cells and neurons leads to the generation of numerous membrane protrusions, an effect that is strongly potentiated upon NGF-induced differentiation. Förster resonance energy transfer (FRET) imaging by fluorescence lifetime microscopy (FLIM) reveals an NGF-induced interaction of activated TC10 with Exo70. Expression of dominant-negative mutants and siRNA-mediated knockdown implicates N-WASP in NGF-induced Exo70-TC10-mediated membrane protrusion. However, FRET imaging of N-WASP activation levels of cells expressing Exo70 and/or constitutively active TC10 reveals that this complex locally antagonises the NGF-induced activation of N-WASP in membrane protrusions. Experiments involving siRNA-mediated knockdown of Cdc42 and overexpression of constitutively active Cdc42 confirm that the Exo70-TC10 complex mainly targets the NGF-induced Cdc42-dependent activation of N-WASP. Our results show that Exo70 is responsible for the correct targeting of the Exo70-TC10 complex to sites of membrane protrusion. The functional uncoupling between both pathways represents a novel regulatory mechanism that enables switching between morphologically distinct – Cdc42- or TC10-dominated – forms of cellular membrane outgrowth.
Key words: Exo70, TC10, Cdc42, N-WASP, Neuronal differentiation
![]()
CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati
Twitter What's this?
This article has been cited by other articles:
![]() |
S. Dupraz, D. Grassi, M. E. Bernis, L. Sosa, M. Bisbal, L. Gastaldi, I. Jausoro, A. Caceres, K. H. Pfenninger, and S. Quiroga The TC10-Exo70 Complex Is Essential for Membrane Expansion and Axonal Specification in Developing Neurons J. Neurosci., October 21, 2009; 29(42): 13292 - 13301. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Munderloh, G. P. Solis, V. Bodrikov, F. A. Jaeger, M. Wiechers, E. Malaga-Trillo, and C. A. O. Stuermer Reggies/Flotillins Regulate Retinal Axon Regeneration in the Zebrafish Optic Nerve and Differentiation of Hippocampal and N2a Neurons J. Neurosci., May 20, 2009; 29(20): 6607 - 6615. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Hala, R. Cole, L. Synek, E. Drdova, T. Pecenkova, A. Nordheim, T. Lamkemeyer, J. Madlung, F. Hochholdinger, J. E. Fowler, et al. An Exocyst Complex Functions in Plant Cell Growth in Arabidopsis and Tobacco PLANT CELL, May 1, 2008; 20(5): 1330 - 1345. [Abstract] [Full Text] [PDF] |
||||