The Human IL-22 Receptor Is Regulated through the Action of the Novel E3 Ligase Subunit FBXW12, Which Functions as an Epithelial Growth Suppressor

Figure 1

E3 ligase subunit FBXW12 decreases cellular levels of human IL-22Ra1. (a) Human IL-22Ra1-V5 plasmid (2 μg) was transiently transfected into Beas-2B human airway epithelial-derived cells with V5-labeled E3 ligase subunits (2 μg) FBXW1, FBXW9 (W9), and so forth and V5 immunoblot at 48 h is shown. (b) FBXW12-V5 and FBXW16-V5 were transfected at increasing doses with IL-22R and analyzed at 48 hr. Densitometric quantitation of (b) is shown in (c). (d) FBXW12-V5 was transfected into Beas-2B cells without IL-22R and IB for V5 (upper panel) and endogenous IL-22R are shown. (e) Beas-2B cells were transfected with IL-22R (2 μg) and vector control or FBXW12 (2 μg) and 48 h later treated with cycloheximide for time indicated; protein stability was assessed by IB and graphed (f). All data are representative of at least 3 separate experiments on 3 days ( for FBXW12 versus vector by Student’s t-test for ).

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