Western blot analysis of extracts from HEK293 cells alone (-), expressing β-arrestin 1 (wt) or β-arrestin (Ser412Ala) mutant (Ala412), using Phospho-β-Arrestin 1 (Ser412) (6-24) Mouse mAb. Lanes 1 and 3 show endogenous levels of phosphorylated β-arrestin 1.
Immunoprecipitation of β-arrestin 1 from HEK293 cells using a polyclonal antibody to phospho-β-arrestin 1 (Ser412), followed by alkaline phosphaphatase (CIP) treatment. β-arrestin 1 was detected by Phospho-beta-Arrestin 1 (Ser412) (6-24) Mouse mAb. CIP treatment abolished the β-arrestin 1 signal, indicating that the monoclonal antibody is phospho-specific.