MATR3 is a post-transcriptional cofactor of HIV-1. A) MATR3 knockdown does not affect the luciferase activity. HeLa cells were transfected with the indicated siRNAs. After 48 hours siRNA-treated cells were transfected with the pNL4.3R-E-luc HIV-1 molecular clone and with pCMV-Renilla and harvested 24 hours later for luciferase assays. Relative Luc/RL expression was normalized to protein levels measured by Bradford assay. The results of three independent experiments are shown ± SD. B) MATR3 knockdown leads to decrease of the Gag expression from pNL4.3R-E-luc HIV-1 molecular clone. HeLa cells were transfected with the siRNA targeting MATR3 (siMATR3) or with a control siRNA (siCTRL). After 48 hours siRNA-treated cells were transfected with pNL4.3R-E-luc and harvested 24 hours later for immunobloting. Tubulin is the protein loading control.