Matrin 3 increases HIV-1 production from transiently tranfected HeLa cells. A) HeLa cells were transfected with pNL4-3 along with WT Matrin 3, and the expression of viral proteins was analyzed on Western blots. Wild type HA-Matrin 3 (lane 2) enhanced viral protein expression. B) Matrin 3 knockdown using siRNA efficiently decreased cell endogenous Matrin 3 (lanes 2 and 3; top panel). Controls were scrambled irrelevant siRNAs. (lower two panels) HeLa cells were transfected with HIV-1 molecular clone pNL4-3 and either the control or the siRNA targeting Matrin 3. Western blot analysis of cell lysates showed that siRNA-mediated Matrin 3 knockdown reduced HIV-1 expression as indicated by decreased p24 expression (lanes 2 and 3). Loadings were normalized to β-actin.