TY - JOUR T1 - Four Different Subunits Are Essential for Expressing the Synaptic Glutamate Receptor at Neuromuscular Junctions of <em>Drosophila</em> JF - The Journal of Neuroscience JO - J. Neurosci. SP - 3209 LP - 3218 DO - 10.1523/JNEUROSCI.4194-04.2005 VL - 25 IS - 12 AU - Gang Qin AU - Tobias Schwarz AU - Robert J. Kittel AU - Andreas Schmid AU - Tobias M. Rasse AU - Dennis Kappei AU - Evgeni Ponimaskin AU - Manfred Heckmann AU - Stephan J. Sigrist Y1 - 2005/03/23 UR - http://www.jneurosci.org/content/25/12/3209.abstract N2 - Three ionotropic glutamate receptor subunits, designated GluRIIA, GluRIIB, and GluRIII, have been identified at neuromuscular junctions of Drosophila. Whereas GluRIIA and GluRIIB are redundant for viability, it was shown recently that GluRIII is essential for both the synaptic localization of GluRIIA and GluRIIB and the viability of Drosophila. Here we identify a fourth and a fifth subunit expressed in the neuromuscular system, which we name GluRIID and GluRIIE. Both new subunits we show to be necessary for survival. Moreover, both GluRIID and GluRIIE are required for the synaptic expression of all other glutamate receptor subunits. All five subunits are interdependent for receptor function, synaptic receptor expression, and viability. This indicates that synaptic glutamate receptors incorporate the GluRIII, GluRIID, and GluRIIE subunit together with either GluRIIA or GluRIIB at the Drosophila neuromuscular junction. At this widely used model synapse, the assembly of four different subunits to form an individual glutamate receptor channel may thus be obligatory. This study opens the way for a further characterization of in vivo glutamate receptor assembly and trafficking using the efficient genetics of Drosophila. ER -