Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2016 Jun 30;8:16. doi: 10.3389/fnsyn.2016.00016

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

Copyright © 2016 Lee, Oh, Seong and Kim.

This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution and reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

PMC Copyright notice

Scheme of dual component synapse detectors. (A) GFP reconstitution-dependent molecular tools detect pre- and postsynaptic membrane apposition through the reconstitution of spGFP fragments each attached to the extracellular ends of membrane protein carriers. Synapse-targeted GFP Reconstitution Across Synaptic Partners (GRASP) utilizes a presynaptic component of spGFP11 (spG11, circular wedge) linked to a CD4-neurexin-1β C-terminus (NxCT) fusion through flexible peptide linkers (gray zigzag), and a postsynaptic component of spGFP1-10 (spG1-10) and truncated neuroligin-1 (tNg) connected with a linker. SpG11 and spG1-10 unite at synapses, not random membrane contacts. In activity-dependent X-RASP the presynaptic split-XFP1-10 (spX1-10) is fused to SNARE proteins such as synaptobrevin (syb), and unites with CD4-bound spG11 when presynaptic activity triggers vesicle release. (B) Neurexin (Nx)-neuroligin (Ng) interaction-dependent molecular tools detect individual synapses through fluorescent protein (FP)-based (SynView) and enzymatic reaction-based (Interaction-Dependent Probe Incorporation Mediated by Enzymes, ID-PRIME) direct visualization of Nx-Ng interaction. In SynView, spG11 is inserted between the esterase and proximal extracellular domain of Ng, and spG1-10 in the middle of the LNS domain of Nx. GFP reconstitutes when Nx and Ng unites. ID-PRIME uses the identical set of synaptic protein carriers, but tandem LAP tags (3xLAP) and lipoic acid ligase A (LplA) are attached to C-terminus of Ng esterase domain and Nx LNS domain, respectively. Nx-Ng interaction initiates LplA-mediated lipoic acid tagging to 3xLAP, and signals useful for imaging originate from antibody-fluorophore conjugates.