title: Evaluation of the role of g protein-coupled receptor kinase 3 in desensitization of mouse odorant receptors in a Mammalian cell line and in olfactory sensory neurons.
abstract: Thousands of odors are sensed and discriminated by G protein-coupled odorant receptors (ORs) expressed in olfactory sensory neurons (OSNs). G protein-coupled receptor kinases (GRKs) may have a role in desensitization of ORs. However, whether ORs are susceptible to agonist-dependent desensitization and whether GRKs affect odorant responsiveness of OSNs are currently unknown. Here we show that GRK3 attenuated the agonist responsiveness of a specific mouse odorant receptor for eugenol (mOR-EG) upon agonist pretreatment in HEK293 cells, but GRK3 did not affect the response amplitude or the recovery kinetics upon repeated agonist stimulation. We performed electrophysiological recordings of single OSNs which expressed mOR-EG and green fluorescent protein (GFP) in the presence or absence of GRK3. The kinetics and amplitude of agonist responsiveness of individual GFP-labeled mOR-EG neurons were not significantly affected by the absence of GRK3. These results indicate that the role of GRK3 in attenuating ORs responsiveness in OSNs may have been overestimated.
authors.affiliation: Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan, Present address: Kansei Laboratories, KAO Corporation, Tokyo 131-8501, Japan.
authors.forename: Aya
authors.initials: A
authors.lastname: Kato
authors.affiliation: Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104-3308, USA and.
authors.forename: Johannes
authors.initials: J
authors.lastname: Reisert
authors.affiliation: Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan, ERATO Touhara Chemosensory Signal Project, JST, The University of Tokyo, Tokyo 113-8657, Japan.
authors.forename: Sayoko
authors.initials: S
authors.lastname: Ihara
authors.affiliation: Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan, Present address: Kansei Laboratories, KAO Corporation, Tokyo 131-8501, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Yoshikawa
authors.affiliation: Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan, ERATO Touhara Chemosensory Signal Project, JST, The University of Tokyo, Tokyo 113-8657, Japan ktouhara@mail.ecc.u-tokyo.ac.jp.
authors.forename: Kazushige
authors.initials: K
authors.lastname: Touhara
mesh_terms: D000818:Animals; D002118:Calcium / Q000032:analysis / Q000378:metabolism; D005054:Eugenol / Q000378:metabolism*; D054770:G-Protein-Coupled Receptor Kinase 3 / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D051379:Mice; D018035:Receptors, Odorant / Q000378:metabolism*; D011984:Sensory Receptor Cells / Q000378:metabolism*; D012903:Smell
chemical_list: D018035:Receptors, Odorant; D005054:Eugenol; D054770:G-Protein-Coupled Receptor Kinase 3; D002118:Calcium
keywords: GRK3; cAMP assay; calcium imaging; electrophysiology; odorant receptor