Localization of XBP1es RNA. RNA purified from the cytoplasmic (C) or nuclear (N) fractions of MA104 cells infected with the RF strain of rotavirus (MOI of 10, 9 h postinfection) was subjected to RT-PCR using XBP1, U6, or GAPDH primers. The PCR DNA products were analyzed by electrophoresis and ethidium bromide staining on two agarose gels. The positions of the XBP1u, XBP1s, and XBP1es PCR DNA products and of the molecular weight markers (MW; sizes are denoted in base pairs) are indicated.