[The TRAF family protein-mediated B cell proliferation signal and the mechanism of LMP1-induced B cell transformation].
We have demonstrated that CD40 signallings induce Bcl-xL, Cdk4 and 6 expression and suppress p27kip-1 expression to block apoptosis and induce B cell proliferation. We have also identified putative signal transducers of CD40, designated TRAF5 and TRAF6, in addition to TRAF1, 2 and 3 demonstrated by others. The EBV transforming protein LMP1 binds to TRAF proteins through the cytoplasmic region required for B cell transformation. Thus, LMP1 appears to be a constitutively activated CD40 receptor on the basis of an ability to aggregate in the plasma membrane and its association with TRAF proteins. However, regulation of the Bcl-xL, Cdk4 and 6 and p27kip-1 expression by LMP1 and the molecular mechanism of LMP1-mediated B cell transformation remain to be elucidated.
Inoue
J
J
Department of Oncology, University of Tokyo.
D017209:Apoptosis / Q000502:physiology; D001402:B-Lymphocytes / Q000276:immunology*; D019013:CD40 Antigens / Q000276:immunology*; D002213:Capsid / Q000276:immunology*; D004854:Herpesvirus 4, Human / Q000276:immunology*; D008213:Lymphocyte Activation / Q000502:physiology*; D018124:Receptors, Tumor Necrosis Factor / Q000276:immunology*; D015398:Signal Transduction / Q000502:physiology*; D014763:Viral Matrix Proteins / Q000276:immunology*
D019013:CD40 Antigens; C037662:EBV-associated membrane antigen, Epstein-Barr virus; D018124:Receptors, Tumor Necrosis Factor; D014763:Viral Matrix Proteins