Fig. 2

Functional activity of selected HERV-K RcREs in a transient transfection assay. The functional activities of the RcREs mapping to C11orf72, cFLAR, RP4linc and U9linc were measured by transfecting the reporter constructs containing each RcRE into 293T/17 cells together with either 50 ng of prRev or prRec or no additional vector. As controls, reporter constructs containing the prRcRE and HIV-1 RRE were also tested. After 72 h, cell supernatants were harvested and supernatant p24 was measured by ELISA. The error bars show the variation between two independent transfections performed at the same time. To determine p values, between Rev and Rec, a two-tailed student t-test was performed using GraphPad Prism 8. Note the different scales shown in a–c. The results shown in c are from an experiment performed on a different day than the results shown in a, b