Regulatory Role Of ALU RNA Transcripted By RNA Polymerase Ii On PKR Phosphorylation

Objective: To study the influence of the ALU's polymerase III (Pol III) promoter on RNA polymerase II (Pol II) transcription, and the effect of Pol II driven Alu transcript on the activity of protein kinase R (PKR) and cell apoptosis.Methods: Recombinant plasmid pcDNA3.1-ALU was obtained by inserting full length Alu sequence downstream of CMV promoter; Alu-293 cells stably expressing Pol II driven Alu transcript were established. The PKR phosphorylation was detected by western blot, the effects on proliferation and apoptosis were examined by MTT assay and Cellular DNA Fragmentation ELISA assay.Results: The Alu sequence directly downstream of CMV promoter can be effectly transcripted by RNA polymerase II. Western blot indicated that the phosphoryaltion level of PKR is higher in Alu-293 cells than in 293 cells,MTT and Cellular DNA Fragmentation ELISA indicated that ALU-293 can result in growth repression and apoptosis.Conclusion: ALU's Pol III promoter has no obvious influence on the RNA polymerase II transcription,Unlike the pol III driven Alu transcript, the Pol II driven Alu transcript can not allevate the interferon activity, On the contrary, it can Strengthen the role of interferon on PKR and induce apoptosis.