Neuroligins/LRRTMs prevent activity- and Ca2+/calmodulin-dependent synapse elimination in cultured neurons.
Submitted by Gilberto J Soler-Llavina on
Title | Neuroligins/LRRTMs prevent activity- and Ca2+/calmodulin-dependent synapse elimination in cultured neurons. |
Publication Type | Journal Article |
Year of Publication | 2011 |
Authors | Ko, J, Soler-Llavina, GJ, Fuccillo, MV, Malenka, RC, Südhof, TC |
Journal | J Cell Biol |
Volume | 194 |
Issue | 2 |
Pagination | 323-34 |
Date Published | 2011 Jul 25 |
ISSN | 1540-8140 |
Abstract | Neuroligins (NLs) and leucine-rich repeat transmembrane proteins (LRRTMs) are postsynaptic cell adhesion molecules that bind to presynaptic neurexins. In this paper, we show that short hairpin ribonucleic acid-mediated knockdowns (KDs) of LRRTM1, LRRTM2, and/or NL-3, alone or together as double or triple KDs (TKDs) in cultured hippocampal neurons, did not decrease synapse numbers. In neurons cultured from NL-1 knockout mice, however, TKD of LRRTMs and NL-3 induced an ∼40% loss of excitatory but not inhibitory synapses. Strikingly, synapse loss triggered by the LRRTM/NL deficiency was abrogated by chronic blockade of synaptic activity as well as by chronic inhibition of Ca(2+) influx or Ca(2+)/calmodulin (CaM) kinases. Furthermore, postsynaptic KD of CaM prevented synapse loss in a cell-autonomous manner, an effect that was reversed by CaM rescue. Our results suggest that two neurexin ligands, LRRTMs and NLs, act redundantly to maintain excitatory synapses and that synapse elimination caused by the absence of NLs and LRRTMs is promoted by synaptic activity and mediated by a postsynaptic Ca(2+)/CaM-dependent signaling pathway. |
DOI | 10.1083/jcb.201101072 |
Alternate Journal | J. Cell Biol. |
PubMed ID | 21788371 |
PubMed Central ID | PMC3144410 |
Grant List | MH086176-02 / MH / NIMH NIH HHS / United States / / Howard Hughes Medical Institute / United States |