Figure 2.
α2AAR agonists promote complex formation between APP and α2AAR in cells and in the mouse brain. A–C) HEK293 cells coexpressing APP with or without HA-α2AAR were treated with 10 µM NE (plus 1 µM prazosin and 1 µM propranolol), clonidine (1 μM), or vehicle. Cell lysates were then subjected to co-IP assays with anti-HA affinity matrix. A, B) Representative Western blots. C) Quantification of the amount of APP coimmunoprecipitated with HA-α2AAR in cells treated with NE for 5 min. Data (means ± sem) are expressed as fold change compared with vehicle control (defined as 1.0) (n = 8 in each group). **P < 0.01, NE vs. control (Student’s t test). D) Control or APP-KO N2a cells expressing HA-α2AAR were stimulated with vehicle or 10 µM NE (plus 1 µM prazosin and 1 µM propranolol) for 5 min. Cell lysates were subjected to co-IP assays using an anti-APP Ab. Representative Western blots are shown. E) Adult HA-α2AAR-knock-in mice were injected (i.p. with saline or 1 mg/kg of clonidine, guanfacine, or UK14304). At 1 h after injection, cortices were dissected and homogenized. Cortical lysates were subjected to IP assays using anti-HA matrix. Representative Western blots are shown.