Naphazoline hydrochloride

Tyramine hydrochloride, (±)-octopamine hydrochloride, dopamine hydrochloride, naphazoline hydrochloride, forskolin, chlorpromazine hydrochloride, phentolamine hydrochloride, and mianserin hydrochloride were all purchased from Sigma-Aldrich (St. Louis, MO, USA). To culture HEK-293 cells, DMEM/F12 medium, fetal bovine serum (FBS), fungizone, penicillin, and streptomycin were purchased from Gibco Cell Culture at Life Technologies (Grand Island, NY, USA). TransIT-LT1 Transfection Reagent was obtained from Mirus Bio LLC (Madison, WI, USA).

Primers (Table S1) used in this manuscript were designed based on the predicted sequence of T. castaneum and synthesized by Invitrogen (Shanghai, China). The pGEM-T Easy Vector (Promega, Madison, WI, USA) was used to clone the PCR amplicon of TcOctβ2R. The expression vector pcDNA3.1(+) was a gift from Dr. Yoonseong Park of Kansas State University. High-quality plasmid DNA prepared by a QIAGEN Plasmid Plus Midi Kit (Hilden, Germany) was used for transient transfection and heterologous expression.
The HEK 293 cells were cultured adherently in a culture medium at 37 °C with 5% CO₂ content. The culture medium was composed of DMEM/F12 medium, 10% fetal bovine serum (FBS), 1% fungizone, and 1% penicillin/streptomycin. Coelenterazine h and the reagents used for cell culture were purchased from Gibco Life Technologies (Grand Island, NY, USA). The TransIT–LT1 transfection reagent used for the transient transfections was purchased from Mirus Bio Chemicals (Madison, WI, USA). OA hydrochloride, dopamine hydrochloride, TA hydrochloride, forskolin, and naphazoline hydrochloride were all purchased from Sigma-Aldrich (St. Louis, MO, USA). The GloSensor reagent used for the cAMP assay was purchased from Promega.