PURPOSE: To isolate and to characterize cells expressing RNA polymerase II tagged with green fluorescent protein for analyses of the effects of ionizing radiation on transcription in living cells. MATERIALS AND METHODS: We introduced an alpha-amanitin-resistant mutation into a vector encoding the largest subunit of RNA polymerase II tagged with green fluorescent protein (GFP-pol). Cell lines stably expressing functional GFP-pol were isolated under selection with alpha-amanitin from a Chinese hamster cell line, CHO-K1, and a radiation-sensitive mutant CHO cell line, XR-1. RESULTS: We tested the functionality of the fusion protein in vivo by determining RNA synthesis activity by incorporation of nucleoside analogues. Both CHO-K1 and XR-1 cells expressing GFP-pol had properties similar to those of their respective parental cell lines, indicating that GFP-pol is functional. CONCLUSIONS: These stable lines might prove useful for analyses of the roles of transcription after ionizing radiation.
PURPOSE: To isolate and to characterize cells expressing RNA polymerase II tagged with green fluorescent protein for analyses of the effects of ionizing radiation on transcription in living cells. MATERIALS AND METHODS: We introduced an alpha-amanitin-resistant mutation into a vector encoding the largest subunit of RNA polymerase II tagged with green fluorescent protein (GFP-pol). Cell lines stably expressing functional GFP-pol were isolated under selection with alpha-amanitin from a Chinese hamster cell line, CHO-K1, and a radiation-sensitive mutant CHO cell line, XR-1. RESULTS: We tested the functionality of the fusion protein in vivo by determining RNA synthesis activity by incorporation of nucleoside analogues. Both CHO-K1 and XR-1 cells expressing GFP-pol had properties similar to those of their respective parental cell lines, indicating that GFP-pol is functional. CONCLUSIONS: These stable lines might prove useful for analyses of the roles of transcription after ionizing radiation.