Transactivated minimal E1b promoter is capable of driving the expression of short hairpin RNA

The strategy that transcribes short hairpin RNAs (shRNAs) by RNA polymerase II promoters is expected to present flexible approaches for regulating the patterns of shRNA expression. The capacity of generating shRNA by a modified adenovirus RNA polymerase II E1b promoter was studied. This 49 bp promoter consists of a TATA-box and an initiation element. It is demonstrated that this modified E1b promoter is capable of driving shRNA transcription and causing either long-term suppression against the target gene in response to the transactivation of constitutively expressed Gal4-VP16 fusion protein or inducible suppression given that the expression of Gal4-VP16 is subject to a dexamethasone inducer.