Cargando…
Multiple regions in the extracellular domain of the glycine receptor determine receptor activity
Glycine receptors (GlyRs) are Cys-loop receptors that mediate fast synaptic inhibition in the brain stem and spinal cord. They are involved in the generation of motor rhythm, reflex circuit coordination, and sensory signal processing and therefore represent targets for therapeutic interventions. The...
Autores principales: | , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Society for Biochemistry and Molecular Biology
2018
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6130964/ https://www.ncbi.nlm.nih.gov/pubmed/29941455 http://dx.doi.org/10.1074/jbc.RA118.003088 |
_version_ | 1783354030888583168 |
---|---|
author | Tang, Bijun Lummis, Sarah C. R. |
author_facet | Tang, Bijun Lummis, Sarah C. R. |
author_sort | Tang, Bijun |
collection | PubMed |
description | Glycine receptors (GlyRs) are Cys-loop receptors that mediate fast synaptic inhibition in the brain stem and spinal cord. They are involved in the generation of motor rhythm, reflex circuit coordination, and sensory signal processing and therefore represent targets for therapeutic interventions. The extracellular domains (ECDs) of Cys-loop receptors typically contain many aromatic amino acids, but only those in the receptor binding pocket have been extensively studied. Here, we show that many Phe residues in the ECD that are not located in the binding pocket are also involved in GlyR function. We examined these Phe residues by creating several GlyR variants, characterizing these variants with the two-electrode voltage clamp technique in Xenopus oocytes, and interpreting changes in receptor parameters by using currently available structural information on the open and closed states of the GlyR. Substitution of six of the eight Phe residues in the ECD with Ala resulted in loss of function or significantly increased the EC(50) and also altered the maximal response to the partial GlyR agonist taurine compared with glycine in those receptor variants that were functional. Substitutions with other amino acids, combined with examination of nearby residues that could potentially interact with these Phe residues, suggested interactions that could be important for GlyR function, and possibly similar interactions could contribute to the function of other members of the Cys-loop receptor family. Overall, our results suggest that many ECD regions are important for GlyR function and that these regions could inform the design of therapeutic agents targeting GlyR activity. |
format | Online Article Text |
id | pubmed-6130964 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | American Society for Biochemistry and Molecular Biology |
record_format | MEDLINE/PubMed |
spelling | pubmed-61309642018-09-11 Multiple regions in the extracellular domain of the glycine receptor determine receptor activity Tang, Bijun Lummis, Sarah C. R. J Biol Chem Neurobiology Glycine receptors (GlyRs) are Cys-loop receptors that mediate fast synaptic inhibition in the brain stem and spinal cord. They are involved in the generation of motor rhythm, reflex circuit coordination, and sensory signal processing and therefore represent targets for therapeutic interventions. The extracellular domains (ECDs) of Cys-loop receptors typically contain many aromatic amino acids, but only those in the receptor binding pocket have been extensively studied. Here, we show that many Phe residues in the ECD that are not located in the binding pocket are also involved in GlyR function. We examined these Phe residues by creating several GlyR variants, characterizing these variants with the two-electrode voltage clamp technique in Xenopus oocytes, and interpreting changes in receptor parameters by using currently available structural information on the open and closed states of the GlyR. Substitution of six of the eight Phe residues in the ECD with Ala resulted in loss of function or significantly increased the EC(50) and also altered the maximal response to the partial GlyR agonist taurine compared with glycine in those receptor variants that were functional. Substitutions with other amino acids, combined with examination of nearby residues that could potentially interact with these Phe residues, suggested interactions that could be important for GlyR function, and possibly similar interactions could contribute to the function of other members of the Cys-loop receptor family. Overall, our results suggest that many ECD regions are important for GlyR function and that these regions could inform the design of therapeutic agents targeting GlyR activity. American Society for Biochemistry and Molecular Biology 2018-09-07 2018-06-25 /pmc/articles/PMC6130964/ /pubmed/29941455 http://dx.doi.org/10.1074/jbc.RA118.003088 Text en © 2018 Tang and Lummis Author's Choice—Final version open access under the terms of the Creative Commons CC-BY license (http://creativecommons.org/licenses/by/4.0) . |
spellingShingle | Neurobiology Tang, Bijun Lummis, Sarah C. R. Multiple regions in the extracellular domain of the glycine receptor determine receptor activity |
title | Multiple regions in the extracellular domain of the glycine receptor determine receptor activity |
title_full | Multiple regions in the extracellular domain of the glycine receptor determine receptor activity |
title_fullStr | Multiple regions in the extracellular domain of the glycine receptor determine receptor activity |
title_full_unstemmed | Multiple regions in the extracellular domain of the glycine receptor determine receptor activity |
title_short | Multiple regions in the extracellular domain of the glycine receptor determine receptor activity |
title_sort | multiple regions in the extracellular domain of the glycine receptor determine receptor activity |
topic | Neurobiology |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6130964/ https://www.ncbi.nlm.nih.gov/pubmed/29941455 http://dx.doi.org/10.1074/jbc.RA118.003088 |
work_keys_str_mv | AT tangbijun multipleregionsintheextracellulardomainoftheglycinereceptordeterminereceptoractivity AT lummissarahcr multipleregionsintheextracellulardomainoftheglycinereceptordeterminereceptoractivity |