To determine the role of protein phosphorylation in transcription regulation, we have treated mouse neuroblastoma N18TG2 cells with the protein kinase inhibitor H-7 and tested its effect on transcription. After the preculture and transfection in the presence of H-7, the cell preparation was divided in half and cultured with and without H-7. The level of CAT expression of pSV2-CAT was found to be higher in the cells cultured in the absence of H-7 than in those cultured in the presence of H-7. This difference was observed only after pretreatment of the cells with H-7, suggesting that withdrawal of H-7 from the culture medium after preculture with H-7 gave an enhancing effect on CAT expression. This phenomenon was also observed with transformants that expressed the CAT gene of pSV2-CAT stably. The 72 base-pair (bp) repeat of SV40 DNA was responsible for this difference in CAT expression. A similar effect of H-7 on the SV40 enhancer activity was observed in mouse neuroblastoma x rat glioma hybrid NG108-15 cells, but not in rat glioma C6-BU-1 cells.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.