Up-regulation of TRIM5 expression in primate cells. A. Schematic representation of the domain structure of TRIM5α and TRIMCyp proteins. C.C.: Coiled-Coil. B. Comparison of TRIM5α or TRIMCyp constitutive expression in HeLa, CMMT, Vero and OMK cells by quantitative RT-PCR. C. MDTF, HeLa, CMMT, Vero or OMK cells were stimulated with universal type I IFN (U), IFN-α, β or γ for 20 min or left untreated (-) and assessed for phosphorylated Stat1 (Tyr 701) and actin by western blot. D. Total RNA was extracted after 8 h of treatment with IFN-α, β or γ. TRIM5α (in HeLa, CMMT and Vero cells) or TRIMCyp (in OMK cells) mRNA expression levels were measured by quantitative RT-PCR and normalized to GAPDH mRNA. Results are expressed as fold increase, defined as the ratio of TRIM5 expression in IFN treated/untreated cells. Error bars reflect the SD of duplicate values in a representative experiment.