Transfection of myc-his–tagged P311 into NIH-3T3 cells. (a and b) RT-PCR and Western blot showing no P311 expression in cells transfected with vector alone and synthesis of P311 mRNA and protein upon P311 transfection. (c) Immunostaining with anti-tagging epitope showing that NIH-3T3 cells transfected with vector alone are negative (left panel), whereas P311-transfected cells (right panel) show rather uniform synthesis of P311 after a month of G418 treatment for selection of transfected cells.