Preferential physical and functional discrimination between E6AP and MAML1 by E6 proteins.

<p>A. Preferential association of E6 proteins for either E6AP or MAML1. HA-tagged E6AP_Ub-, MAML1 and GFP expression plasmids were co-transfected with the indicated FLAG-tagged E6 expression plasmids into 293T cells and harvested 18 hrs. later in 0.5X IPEGAL lysis buffer as described in the methods. Western blots of input samples are clustered at the top and FLAG immune precipitated samples at the bottom, except that lane 1 at the bottom cluster of blots is an input sample, same as lane 2 in the top cluster of blots. Input was 4% of the immune precipitated sample size. E6* is a spliced and truncated E6 variant. B. Alpha genera and selected genus E6 proteins reduce the expression of E6AP upon co-expression. HA-tagged E6AP, HA-GFP and the indicated FLAG-tagged E6 proteins were co-transfected into 293T cells and cells were lysed in SDS sample buffer 18 hrs. later.