Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Subscribe

Logo for

J. Cell Biol. 161 (1): 131-142

Copyright © 2003 by the Rockefeller University Press.


Article

Synapse formation is regulated by the signaling adaptor GIT1

Huaye Zhang, Donna J. Webb, Hannelore Asmussen, and Alan F. Horwitz

Department of Cell Biology, University of Virginia, Charlottesville, VA 22908

Address correspondence to Alan F. Horwitz, Dept. of Cell Biology, UVA School of Medicine, P.O. Box 800732, Charlottesville, VA 22908-0732 (for express mail add 1300 Jefferson Park Ave.). Tel.: (434) 243-6813. Fax: 434-982-3912. E-mail: horwitz{at}virginia.edu

Abstract: Dendritic spines in the central nervous system undergo rapid actin-based shape changes, making actin regulators potential modulators of spine morphology and synapse formation. Although several potential regulators and effectors for actin organization have been identified, the mechanisms by which these molecules assemble and localize are not understood. Here we show that the G protein–coupled receptor kinase–interacting protein (GIT)1 serves such a function by targeting actin regulators and locally modulating Rac activity at synapses. In cultured hippocampal neurons, GIT1 is enriched in both pre- and postsynaptic terminals and targeted to these sites by a novel domain. Disruption of the synaptic localization of GIT1 by a dominant-negative mutant results in numerous dendritic protrusions and a significant decrease in the number of synapses and normal mushroom-shaped spines. The phenotype results from mislocalized GIT1 and its binding partner PIX, an exchange factor for Rac. In addition, constitutively active Rac shows a phenotype similar to the GIT1 mutant, whereas dominant-negative Rac inhibits the dendritic protrusion formation induced by mislocalized GIT1. These results demonstrate a novel function for GIT1 as a key regulator of spine morphology and synapse formation and point to a potential mechanism by which mutations in Rho family signaling leads to decreased neuronal connectivity and cognitive defects in nonsyndromic mental retardation.

Key Words: synapse formation; GIT1; PIX; Rac; spine morphology


* Abbreviations used in this paper: ARF, ADP-ribosylation factor; GAP, GTPase-activating protein; GEF, guanine nucleotide exchange factor; GIT, G protein–coupled receptor kinase–interacting protein; MR, mental retardation; PAK, p21-activated kinase; SHD, Spa2 homology domain; SLD, synaptic localization domain.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
{alpha}PIX RhoGEF Supports Positive Selection by Restraining Migration and Promoting Arrest of Thymocytes.
M. Korthals, K. Schilling, P. Reichardt, D. Mamula, T. Schluter, M. Steiner, K. Langnase, U. Thomas, E. Gundelfinger, R. T. Premont, et al. (2014)
J. Immunol. 192, 3228-3238
   Abstract »    Full Text »    PDF »
Rho-GTPase-activating Protein Interacting with Cdc-42-interacting Protein 4 Homolog 2 (Rich2): A NEW Ras-RELATED C3 BOTULINUM TOXIN SUBSTRATE 1 (Rac1) GTPase-ACTIVATING PROTEIN THAT CONTROLS DENDRITIC SPINE MORPHOGENESIS.
F. Raynaud, E. Moutin, S. Schmidt, J. Dahl, F. Bertaso, T. M. Boeckers, V. Homburger, and L. Fagni (2014)
J. Biol. Chem. 289, 2600-2609
   Abstract »    Full Text »    PDF »
GluN3A expression restricts spine maturation via inhibition of GIT1/Rac1 signaling.
M. Fiuza, I. Gonzalez-Gonzalez, and I. Perez-Otano (2013)
PNAS 110, 20807-20812
   Abstract »    Full Text »    PDF »
Rac GEF Dock4 interacts with cortactin to regulate dendritic spine formation.
S. Ueda, M. Negishi, and H. Katoh (2013)
Mol. Biol. Cell 24, 1602-1613
   Abstract »    Full Text »    PDF »
The Adaptor Protein and Arf GTPase-activating Protein Cat-1/Git-1 Is Required for Cellular Transformation.
S. M. Yoo, M. A. Antonyak, and R. A. Cerione (2012)
J. Biol. Chem. 287, 31462-31470
   Abstract »    Full Text »    PDF »
Arf6-GEF BRAG1 Regulates JNK-Mediated Synaptic Removal of GluA1-Containing AMPA Receptors: A New Mechanism for Nonsyndromic X-Linked Mental Disorder.
K. R. Myers, G. Wang, Y. Sheng, K. K. Conger, J. E. Casanova, and J. J. Zhu (2012)
J. Neurosci. 32, 11716-11726
   Abstract »    Full Text »    PDF »
{beta}-Pix Modulates Actin-Mediated Recruitment of Synaptic Vesicles to Synapses.
Y. Sun and S. X. Bamji (2011)
J. Neurosci. 31, 17123-17133
   Abstract »    Full Text »    PDF »
The RhoG/ELMO1/Dock180 Signaling Module Is Required for Spine Morphogenesis in Hippocampal Neurons.
J.-Y. Kim, M. H. Oh, L. P. Bernard, I. G. Macara, and H. Zhang (2011)
J. Biol. Chem. 286, 37615-37624
   Abstract »    Full Text »    PDF »
Vasodilator-stimulated Phosphoprotein (VASP) Induces Actin Assembly in Dendritic Spines to Promote Their Development and Potentiate Synaptic Strength.
W.-H. Lin, C. A. Nebhan, B. R. Anderson, and D. J. Webb (2010)
J. Biol. Chem. 285, 36010-36020
   Abstract »    Full Text »    PDF »
Regulation of Synaptic Rac1 Activity, Long-Term Potentiation Maintenance, and Learning and Memory by BCR and ABR Rac GTPase-Activating Proteins.
D. Oh, S. Han, J. Seo, J.-R. Lee, J. Choi, J. Groffen, K. Kim, Y. S. Cho, H.-S. Choi, H. Shin, et al. (2010)
J. Neurosci. 30, 14134-14144
   Abstract »    Full Text »    PDF »
NOS1AP Associates with Scribble and Regulates Dendritic Spine Development.
L. Richier, K. Williton, L. Clattenburg, K. Colwill, M. O'Brien, C. Tsang, A. Kolar, N. Zinck, P. Metalnikov, W. S. Trimble, et al. (2010)
J. Neurosci. 30, 4796-4805
   Abstract »    Full Text »    PDF »
G-protein-coupled Receptor Kinase-interacting Proteins Inhibit Apoptosis by Inositol 1,4,5-Triphosphate Receptor-mediated Ca2+ Signal Regulation.
S. Zhang, C. Hisatsune, T. Matsu-ura, and K. Mikoshiba (2009)
J. Biol. Chem. 284, 29158-29169
   Abstract »    Full Text »    PDF »
EphA2 Engages Git1 to Suppress Arf6 Activity Modulating Epithelial Cell-Cell Contacts.
K. Miura, J.-M. Nam, C. Kojima, N. Mochizuki, and H. Sabe (2009)
Mol. Biol. Cell 20, 1949-1959
   Abstract »    Full Text »    PDF »
Preso, A Novel PSD-95-Interacting FERM and PDZ Domain Protein That Regulates Dendritic Spine Morphogenesis.
H. W. Lee, J. Choi, H. Shin, K. Kim, J. Yang, M. Na, S. Y. Choi, G. B. Kang, S. H. Eom, H. Kim, et al. (2008)
J. Neurosci. 28, 14546-14556
   Abstract »    Full Text »    PDF »
A neuron-specific cytoplasmic dynein isoform preferentially transports TrkB signaling endosomes.
J. Ha, K. W.-H. Lo, K. R. Myers, T. M. Carr, M. K. Humsi, B. A. Rasoul, R. A. Segal, and K. K. Pfister (2008)
J. Cell Biol. 181, 1027-1039
   Abstract »    Full Text »    PDF »
Erbin Controls Dendritic Morphogenesis by Regulating Localization of {delta}-Catenin.
J. Arikkath, I. Israely, Y. Tao, L. Mei, X. Liu, and L. F. Reichardt (2008)
J. Neurosci. 28, 7047-7056
   Abstract »    Full Text »    PDF »
N-WASP and the Arp2/3 Complex Are Critical Regulators of Actin in the Development of Dendritic Spines and Synapses.
A. M. Wegner, C. A. Nebhan, L. Hu, D. Majumdar, K. M. Meier, A. M. Weaver, and D. J. Webb (2008)
J. Biol. Chem. 283, 15912-15920
   Abstract »    Full Text »    PDF »
P-Rex2 regulates Purkinje cell dendrite morphology and motor coordination.
S. Donald, T. Humby, I. Fyfe, A. Segonds-Pichon, S. A. Walker, S. R. Andrews, W. J. Coadwell, P. Emson, L. S. Wilkinson, and H. C. E. Welch (2008)
PNAS 105, 4483-4488
   Abstract »    Full Text »    PDF »
Presynaptic establishment of the synaptic cleft extracellular matrix is required for post-synaptic differentiation.
J. Rohrbough, E. Rushton, E. Woodruff III, T. Fergestad, K. Vigneswaran, and K. Broadie (2007)
Genes & Dev. 21, 2607-2628
   Abstract »    Full Text »    PDF »
Differential Expression of the ARF GAP Genes GIT1 and GIT2 in Mouse Tissues.
R. Schmalzigaug, H. Phee, C. E. Davidson, A. Weiss, and R. T. Premont (2007)
Journal of Histochemistry & Cytochemistry 55, 1039-1048
   Abstract »    Full Text »    PDF »
Role of Phospholipase C{gamma}1 in Cell Spreading Requires Association with a {beta}-Pix/GIT1-Containing Complex, Leading to Activation of Cdc42 and Rac1.
N. P. Jones and M. Katan (2007)
Mol. Cell. Biol. 27, 5790-5805
   Abstract »    Full Text »    PDF »
The neuronal Arf GAP centaurin {alpha}1 modulates dendritic differentiation.
C. D. Moore, E. E. Thacker, J. Larimore, D. Gaston, A. Underwood, B. Kearns, S. I. Patterson, T. Jackson, C. Chapleau, L. Pozzo-Miller, et al. (2007)
J. Cell Sci. 120, 2683-2693
   Abstract »    Full Text »    PDF »
Induction of Vascular Permeability: betaPIX and GIT1 Scaffold the Activation of Extracellular Signal-regulated Kinase by PAK.
R. Stockton, J. Reutershan, D. Scott, J. Sanders, K. Ley, and M. A. Schwartz (2007)
Mol. Biol. Cell 18, 2346-2355
   Abstract »    Full Text »    PDF »
{alpha}5 Integrin Signaling Regulates the Formation of Spines and Synapses in Hippocampal Neurons.
D. J. Webb, H. Zhang, D. Majumdar, and A. F. Horwitz (2007)
J. Biol. Chem. 282, 6929-6935
   Abstract »    Full Text »    PDF »
Abeta1-42 stimulates actin polymerization in hippocampal neurons through Rac1 and Cdc42 Rho GTPases.
A. Mendoza-Naranjo, C. Gonzalez-Billault, and R. B. Maccioni (2007)
J. Cell Sci. 120, 279-288
   Abstract »    Full Text »    PDF »
Transgenic Mouse Proteomics Identifies New 14-3-3-associated Proteins Involved in Cytoskeletal Rearrangements and Cell Signaling.
P.-O. Angrand, I. Segura, P. Volkel, S. Ghidelli, R. Terry, M. Brajenovic, K. Vintersten, R. Klein, G. Superti-Furga, G. Drewes, et al. (2006)
Mol. Cell. Proteomics 5, 2211-2227
   Abstract »    Full Text »    PDF »
Sequential implication of the mental retardation proteins ARHGEF6 and PAK3 in spine morphogenesis.
R. Node-Langlois, D. Muller, and B. Boda (2006)
J. Cell Sci. 119, 4986-4993
   Abstract »    Full Text »    PDF »
Identification of phosphorylation sites in GIT1.
D. J. Webb, M. W. Mayhew, M. Kovalenko, M. J. Schroeder, E. D. Jeffery, L. Whitmore, J. Shabanowitz, D. F. Hunt, and A. F. Horwitz (2006)
J. Cell Sci. 119, 2847-2850
   Full Text »    PDF »
Paxillin phosphorylation at Ser273 localizes a GIT1-PIX-PAK complex and regulates adhesion and protrusion dynamics.
A. Nayal, D. J. Webb, C. M. Brown, E. M. Schaefer, M. Vicente-Manzanares, and A. R. Horwitz (2006)
J. Cell Biol. 173, 587-589
   Abstract »    Full Text »    PDF »
ARF6 and EFA6A regulate the development and maintenance of dendritic spines..
S. Choi, J. Ko, J.-R. Lee, H. W. Lee, K. Kim, H. S. Chung, H. Kim, and E. Kim (2006)
J. Neurosci. 26, 4811-4819
   Abstract »    Full Text »    PDF »
The multifunctional GIT family of proteins.
R. J. Hoefen and B. C. Berk (2006)
J. Cell Sci. 119, 1469-1475
   Abstract »    Full Text »    PDF »
Regulation of Neuroendocrine Exocytosis by the ARF6 GTPase-activating Protein GIT1.
M. Z. Meyer, N. Deliot, S. Chasserot-Golaz, R. T. Premont, M.-F. Bader, and N. Vitale (2006)
J. Biol. Chem. 281, 7919-7926
   Abstract »    Full Text »    PDF »
A GIT1/PIX/Rac/PAK Signaling Module Regulates Spine Morphogenesis and Synapse Formation through MLC.
H. Zhang, D. J. Webb, H. Asmussen, S. Niu, and A. F. Horwitz (2005)
J. Neurosci. 25, 3379-3388
   Abstract »    Full Text »    PDF »
Regulation of Dendritic Spine Morphogenesis by Insulin Receptor Substrate 53, a Downstream Effector of Rac1 and Cdc42 Small GTPases.
J. Choi, J. Ko, B. Racz, A. Burette, J.-R. Lee, S. Kim, M. Na, H. W. Lee, K. Kim, R. J. Weinberg, et al. (2005)
J. Neurosci. 25, 869-879
   Abstract »    Full Text »    PDF »
The role of the Rho GTPases in neuronal development.
E.-E. Govek, S. E. Newey, and L. Van Aelst (2005)
Genes & Dev. 19, 1-49
   Abstract »    Full Text »    PDF »
Abi2-Deficient Mice Exhibit Defective Cell Migration, Aberrant Dendritic Spine Morphogenesis, and Deficits in Learning and Memory.
M. Grove, G. Demyanenko, A. Echarri, P. A. Zipfel, M. E. Quiroz, R. M. Rodriguiz, M. Playford, S. A. Martensen, M. R. Robinson, W. C. Wetsel, et al. (2004)
Mol. Cell. Biol. 24, 10905-10922
   Abstract »    Full Text »    PDF »
The Mental Retardation Protein PAK3 Contributes to Synapse Formation and Plasticity in Hippocampus.
B. Boda, S. Alberi, I. Nikonenko, R. Node-Langlois, P. Jourdain, M. Moosmayer, L. Parisi-Jourdain, and D. Muller (2004)
J. Neurosci. 24, 10816-10825
   Abstract »    Full Text »    PDF »
GIT1 Activates p21-Activated Kinase through a Mechanism Independent of p21 Binding.
T.-H. Loo, Y.-W. Ng, L. Lim, and E. Manser (2004)
Mol. Cell. Biol. 24, 3849-3859
   Abstract »    Full Text »    PDF »

To Advertise     Find Products


Science Signaling. ISSN 1937-9145 (online), 1945-0877 (print). Pre-2008: Science's STKE. ISSN 1525-8882