| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Istituto di Neuroscienze CNR and Dipartimento di Scienze Biomediche Sperimentali, Università di Padova, Viale G. Colombo 3, 35121 Padova, Italy
2 International School For Advanced Studied (SISSA-ISAS), Neuroscience Program, Trieste, Italy
3 Dipartimento di Farmacologia Medica and Istituto di Neuroscienze CNR, Università di Milano, Via Vanvitelli 32, 20129 Milano, Italy
The SNARE-dependent exocytosis of glutamate-containing vesicles in astrocytes is increasingly viewed as an important signal at the basis of the astrocyte-to-neurone communication system in the brain. Here we provide further insights into the molecular features and dynamics of vesicles in cultured astrocytes. We found that immunoisolated synaptobrevin2 vesicles are clear vesicles quite heterogenous in size and contain the vesicular glutamate transporter v-Glut-2. Moreover, they are immunopositive for synaptotagmin IV, for AMPA receptor subunits GluR2,3 and, to a lesser extent, for GluR1. We also provide direct evidence for the functional expression of v-Glut-2 in astrocytes and demonstrate that synaptobrevin2-positive vesicles can specifically take up (3H)L-glutamate via a bafilomycin-sensitive mechanism. Finally, by time lapse confocal microscopy, we show that a subpopulation of vesicles (tagged with a synaptobrevin2–EGFP chimera) is highly mobile and can fuse with the plasma membrane, preferentially at the level of the astrocyte processes, in a Ca2+-dependent manner. These latter observations, together with the evidence reported here for the expression of functional v-Glut-2 in synaptobrevin2-positive vesicles, provide a molecular basis for regulated exocytosis in astrocyte.
(Received 5 July 2005;
accepted after revision 30 November 2005;
first published online 1 December 2005)
Corresponding author G. Carmignoto: Istituto di Neuroscienze CNR and Dipartimento di Scienze Biomediche Sperimentali, Università di Padova, Viale G. Colombo 3, 35121 Padova, Italy. Email: gcarmi{at}bio.unipd.it
This article has been cited by other articles:
|
|
 |
|
  J. Marchaland, C. Cali, S. M. Voglmaier, H. Li, R. Regazzi, R. H. Edwards, and P. Bezzi Fast Subplasma Membrane Ca2+ Transients Control Exo-Endocytosis of Synaptic-Like Microvesicles in Astrocytes J. Neurosci., September 10, 2008; 28(37): 9122 - 9132. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Li, N. Ropert, A. Koulakoff, C. Giaume, and M. Oheim Lysosomes Are the Major Vesicular Compartment Undergoing Ca2+-Regulated Exocytosis from Cortical Astrocytes J. Neurosci., July 23, 2008; 28(30): 7648 - 7658. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Xu, H. Peng, N. Kang, Z. Zhao, J. H-C. Lin, P. K. Stanton, and J. Kang Glutamate-induced Exocytosis of Glutamate from Astrocytes J. Biol. Chem., August 17, 2007; 282(33): 24185 - 24197. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Nadrigny, D. Li, K. Kemnitz, N. Ropert, A. Koulakoff, S. Rudolph, M. Vitali, C. Giaume, F. Kirchhoff, and M. Oheim Systematic Colocalization Errors between Acridine Orange and EGFP in Astrocyte Vesicular Organelles Biophys. J., August 1, 2007; 93(3): 969 - 980. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Domercq, L. Brambilla, E. Pilati, J. Marchaland, A. Volterra, and P. Bezzi P2Y1 Receptor-evoked Glutamate Exocytosis from Astrocytes: CONTROL BY TUMOR NECROSIS FACTOR-{alpha} AND PROSTAGLANDINS J. Biol. Chem., October 13, 2006; 281(41): 30684 - 30696. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. G. Haydon and G. Carmignoto Astrocyte control of synaptic transmission and neurovascular coupling. Physiol Rev, July 1, 2006; 86(3): 1009 - 1031. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
