All data are expressed as the mean ± SEM. In the figures, average traces are shown as the mean (line) ± the SEM (shaded regions or

bars). A two-tailed t test was used to determine significance of differences across conditions in Figure 2 and Figure 5. p < 0.05 ABT-888 nmr was considered significant. The authors thank members of the Sabatini laboratory and G. Pekkurnaz for helpful comments during the preparation of the manuscript. We thank S.D. Liberles, L.B. Buck, and J. Lemon for assistance with the SEAP assays and for the gift of reagents; J.L. Whistler for the mu opioid receptor plasmid DNA; J.B. Cohen and D.C. Chiara for HPLC access; J.T. Williams for insightful discussions; R. Shah for technical support; and the ICCB-Longwood screening facility for access to plate readers. The work was funded by a grant from the Helen

Hay Whitney Foundation (postdoctoral fellowship) to M.R.B. and a grant from the National Institute of Mental Health (MH085498) to B.L.S. M.R.B. conducted the experiments and data analysis. M.R.B. and B.L.S. designed the experiments and wrote the manuscript. “
“Constitutive Sunitinib price and regulated exocytosis play critical roles in the delivery of proteins to the plasma membrane and the release of substances into the extracellular environment. These events are frequently targeted to specific subcellular domains that

mediate distinct cellular functions. A prototypic example of such subcellular specialization occurs only at mammalian excitatory synapses. Presynaptic nerve terminals contain an active zone composed of a web of scaffolding proteins, ion channels, and neurotransmitter-containing vesicles, some of which sit docked at the plasma membrane waiting for the appropriate signal to trigger their fusion. Like all intracellular membrane fusion events except for mitochondrial fusion, the exocytosis of presynaptic vesicles requires assembly of SNARE complexes that are composed of the plasma membrane proteins syntaxin-1 and SNAP 25 and of the vesicle protein synaptobrevin/VAMP (Südhof, 2004 and Südhof and Rothman, 2009). SNARE complex formation is critical for bringing the vesicle and plasma membrane into tight apposition and thereby preparing the vesicle for fusion (Rizo and Rosenmund, 2008, Südhof and Rothman, 2009 and Weber et al., 1998). The actual exocytotic fusion event, however, is prevented until an action potential invades the terminal and elicits a rise in calcium at which point neurotransmitter release occurs within one millisecond. Calcium triggers fusion pore opening by binding to synaptotagmins, which are calcium sensors for synaptic vesicle exocytosis (Fernández-Chacón et al., 2001 and Südhof and Rothman, 2009).