Analysis of the expression levels of LT-Ag from JCV Pt and SV40 Pt backgrounds. (A) PHFG cells were transfected/infected either with JCV Mad-1 WT or its Pt mutant genome, nuclear and whole-cell extracts prepared at the indicated time points and analyzed by Western blot for LT-Ag and agnoprotein respectively. Lamin A/C was also probed for equal loading of the nuclear extracts for LT-Ag using anti-lamin A/C polyclonal antibody (Cat #: 2032, Cell signaling). Western blotting with anti-Grb2 monoclonal antibody (Santa Cruz, C-7, Cat #: sc-8034) demonstrates the equal loading of the samples for agnoprotein expression (bottom panel). (B) CV-1 cells were transfected either with SV40(776) WT or its Pt mutant genome, the whole-cell and nuclear extracts prepared at the days indicated and analyzed by Western blot for agnoprotein and LT-Ag expression. An unlabeled arrow points to the band that is recognized by anti-Agno antibody which serves as a loading control for the agnoprotein samples. In lane 1, nuclear extracts prepared from untransfected cells were loaded as negative control (- Cont.).