ObjectiveTo establish 16HBE cell lines stably expressing glutathione S-transferase mu 5 (GSTM5) gene, and explore the mechanism of GSTM5 nuclear translocation. MethodsRecombinant lentiviral expression vector containing GSTM5 gene was constructed and lentivirus was produced. After lentivirus infection of 16HBE cells, 16HBE-GSTM5 cell lines were obtained by screening with puromycin. Expression of GSTM5 in different cells was examined by RT-qPCR and Western blot. The nuclear translocation of GSTM5 was observed by confocal laser scanning microscope, after the 16HBE-GSTM5 cell lines were treated with tumor necrosis factor-α (TNF-α; 10 ng/ml) for 0.5 hour. ResultsLentiviral expression plasmids, PLVX-puro-3*flag-SBP-GSTM5-C and PLVX-puro-GSTM5-SBP-3*flag-N, were constructed and lentiviral particles were successfully packed. After infected with lentivirus and screened by puromycin, two cell lines, 16HBE-GSTM5-SBP-3*flag-N and 16HBE-3*flag-SBP-GSTM5-C, were obtained. GSTM5 expression in these two cell lines was significantly higher compared with the control group and parental cells. After treated with TNF-α for 0.5 hour, the nuclear translocation of GSTM5 in 16HBE-GSTM5-SBP-3*flag-N was much more obviously than that in 16HBE-3*flag-SBP-GSTM5-C. ConclusionThe N-terminal region of GSTM5 is critical for nuclear translocation induced by TNF-α, which is mediated by a novel and non-classical nuclear localization signal.
