Does the same U1 promoter in the SureSilencing shRNA Plasmids express shRNA in human, mouse, and rat cell lines?

Yes, the human, mouse, and rat Pol II enzymes transcribe from the human U1 promoter of the SureSilencing shRNA Plasmids with equal efficiency and effectiveness. The sequence identity of the promoters in the three different species is similar enough that enzymes from each species will recognize and bind the others.