Inhibition of CD99 by LMP1 is markedly restored by a constitutively active form of the κB inhibitory protein, IκBαS32/36A.
(A) Effect of IκBαS32/36A on the CD99 promoter activity in the presence or absence of LMP1. A half microgram of the reporter construct, p(−317/+123)luc, was cotransfected with increasing amounts (μg) of the construct expressing FLAG-IκBαS32/36A. The same filter was probed with monoclonal antibodies such as CS1-4, M5, anti-Calnexin for LMP1, FLAG- IκBαS32/36A, and Calnexin, respectively. One microgram pNF-κB CAT was cotransfected to confirm the functions of cotransfected LMP1 and FLAG-IκBαS32/36A. Values represent the mean of 3 independent transfections. (B) Relative CD99 promoter activities with various JNK constructs in the presence or absence of LMP1. M5 monoclonal antibody was used for the detection of the wild-type JNK (pcDNA3-FLAG-JNK) and its dominant-negative form, shown as JNKDN (pcDNA3-FLAG-JNK(apf)). The reporter construct, AP-1 CAT, was cotransfected to confirm the activity of cotransfected JNKs. Relative luciferase activity values represent mean of 3 independent transfections, whereas CAT values are the averages of 2 transfections among them.
