A versatile optical tool for studying synaptic GABAA receptor trafficking.
J Cell Sci
; 130(22): 3933-3945, 2017 Nov 15.
Article
en En
| MEDLINE
| ID: mdl-29025969
ABSTRACT
Live-cell imaging methods can provide critical real-time receptor trafficking measurements. Here, we describe an optical tool to study synaptic γ-aminobutyric acid (GABA) type A receptor (GABAAR) dynamics through adaptable fluorescent-tracking capabilities. A fluorogen-activating peptide (FAP) was genetically inserted into a GABAAR γ2 subunit tagged with pH-sensitive green fluorescent protein (γ2pHFAP). The FAP selectively binds and activates Malachite Green (MG) dyes that are otherwise non-fluorescent in solution. γ2pHFAP GABAARs are expressed at the cell surface in transfected cortical neurons, form synaptic clusters and do not perturb neuronal development. Electrophysiological studies show γ2pHFAP GABAARs respond to GABA and exhibit positive modulation upon stimulation with the benzodiazepine diazepam. Imaging studies using γ2pHFAP-transfected neurons and MG dyes show time-dependent receptor accumulation into intracellular vesicles, revealing constitutive endosomal and lysosomal trafficking. Simultaneous analysis of synaptic, surface and lysosomal receptors using the γ2pHFAP-MG dye approach reveals enhanced GABAAR turnover following a bicucculine-induced seizure paradigm, a finding not detected by standard surface receptor measurements. To our knowledge, this is the first application of the FAP-MG dye system in neurons, demonstrating the versatility to study nearly all phases of GABAAR trafficking.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas Recombinantes de Fusión
/
Receptores de GABA-A
Límite:
Animals
/
Humans
Idioma:
En
Revista:
J Cell Sci
Año:
2017
Tipo del documento:
Article
País de afiliación:
Estados Unidos