Effect of ectopic expression of a dominant negative mutant of hnRNP A1 in HTLV-1 producing C91PL cells. (A) Primer location on HTLV-1 mRNA; (B) Analysis of the nucleo-cytoplasmic distribution of viral gene expression in NLS-A1- and LXSP- transduced cells. Four days after transduction, mRNAs were extracted from the nuclear and cytoplasmic compartments of each cell type and levels of unspliced (gag/pol), singly spliced (env) and doubly spliced (tax/rex) mRNAs were reverse transcribed and quantified by real-time quantitative PCR (RQ-PCR), by using specific primers. Results are expressed as the amount of nuclear (grey bar) and cytoplasmic (black bar) indicated mRNA relative to β-actin. (C) Evaluation of the nuclear export rate (NER) of Rex-dependent (gag/pol plus env) mRNA and of Rex-independent (tax/rex) mRNA in NLS-A1- or LXSP- transduced C91PL cells. Numbers are the ratio between cytoplasmic (C) to total (T) RNA and nuclear (N) to total RNA.