Journal: Bio-protocol
Article Title: Single-Particle Tracking of AMPA Receptor-Containing Vesicles
doi: 10.21769/BioProtoc.5325
Figure Lengend Snippet: (A) Constructs used to insert HaloTag into the genomic loci of Gria1 using homology-independent targeted integration (HITI). The donor construct (Donor) contains the DNA sequence coding for HaloTag (HaloTag) and the single guide RNA that will target Cas9 to Gria1 (sgRNA). Importantly, the HaloTag coding sequence is flanked by Gria1 sequences that will be targeted and cut by Cas9 (red bars). Cas9 is expressed from a second plasmid (Cas9). Black bars represent promoters driving the expression of Cas9 and the sgRNA. (B) Cas9 creates double-strand breaks in the genomic loci of Gria1 and releases HaloTag from the Donor. HaloTag can be inserted into Gria1 by non-homologous end joining (NHEJ). When expressed from the edited copy of Gria1 (Gria1-HT ), GluA1 will contain HaloTag inserted into its amino-terminal domain (ATD; GluA1-HT). SP, signal peptide; LBD, ligand-binding domain; TMD, transmembrane domain; CT, C-terminal tail. (C) Diagram of AMPAR containing a GluA1 subunit (blue) with HaloTag (green) inserted into the ATD (red). AMPARs are tetramers that can contain zero to four GluA1 subunits. As HaloTag is inserted into the ATD, it will sit on the extracellular side of the receptor. HaloTag can be labeled with fluorescent dyes that are conjugated to HaloTag ligand (HTL), such as JF 549 -HTL. (D) Representative confocal image of a cultured rat hippocampal neuron expressing GluA1 tagged with HaloTag and labeled with JF 549 -HTL (GluA1-HT-JF 549 ). Scale bar, 25 μm. (E) Representative widefield images of edited neurons expressing GluA1-HT labeled with JF 549 -HTL (GluA1-HT-JF 549 ) and a fluorescent neuron marker (in this case, miRFP670 driven by a synapsin promoter). Scale bar, 100 μm.
Article Snippet: Prior to dissection, prepare a 1.5 mL Eppendorf tube with the donor and Cas9 expression plasmids by pipetting 0.5 μg of PX551 and 0.5 μg of px552-sg-gria1-HT in a 1.5 mL Eppendorf tube.
Techniques: Construct, Sequencing, Plasmid Preparation, Expressing, Non-Homologous End Joining, Ligand Binding Assay, Labeling, Cell Culture, Marker