LMP2B coimmunoprecipitates with LMP2A. Whole-cell protein lysates of Akata-LMP2B pool 2 (2B-2) and the Akata-vector control were immunoprecipitated (IP) with anti-LMP2A (A). The IPs were separated on a SDS gel and immunoblotted (IB) against FLAG and LMP2A. The heavy band in the LMP2A immunoblot represents the heavy Ig chain of the mouse antibody used for pull-down, whereas the lower, narrow band represents the equal amount of LMP2A pulled down in 2B-2 and vector input lysates. (B) The input lysate of 2B-2 was split into IPs without antibody, against c-myc, and FLAG and immunoblotted (three dilutions; 1×, 0.2×, 0.04×) against FLAG. No unspecific pull-down with anti-c-myc was observed due to the overexpression of FLAG-LMP2B. (C) The same IPs as those used in panel B were loaded on a SDS gel and immunoblotted against c-myc to verify that the IP was working. The upper band (65 kDa) and the lower band (63 kDa) in the input lysate of 2B-2 represent two forms of c-myc.