MCPyV ST increases LT protein levels independently of Fbw7, but dependent on the LSD.

(A) A co-immunoprecipitation between MCPyV T antigens (LT, ST, ST ΔLSD) and Fbw7 was performed through pull-down of the T antigens (XT10—common-T antibody) and detection of co-immunoprecipitated Fbw7 (anti-FLAG). (B) Fbw7 knockdown was confirmed in 293A cells transduced with lentiviruses containing shControl or shFbw7 by pulling down and immunoblotting for Fbw7 (A301-720). (C) Endogenous c-Myc protein levels were assessed by western blot in 293A expressing shControl, shFbw7, and/or MCPyV ST. (D) MCPyV LT protein levels were assessed in control and Fbw7 knockdown 293A cells with and without ST or ST ΔLSD co-expression.