The oncoprotein LMP1 mimics an activated CD40 receptor, yet it is not known whether
constitutive CD40 signaling, like LMP1, is sufficient to transform cells. Here we demonstrate
that constitutive activation of the CD40 pathway by a chimeric LMP1CD40 molecule
resembles the transforming function of LMP1 in inducing loss of contact inhibition and
anchorage independent growth of Rat1 fibroblasts. Rat1 transformation correlates with the
expression level of LMP1CD40 and depends on its ability to oligomerize. Our data provide …