FIG. 4.

An NES peptide that functions as a specific CRM1 inhibitor in vivo. A mixture of ³²P-labelled in vitro-transcribed ftz pre-mRNA, U1ΔSm snRNA, U6Δss snRNA, and initiator methionyl-tRNA (tRNA_metⁱ) were injected into Xenopus oocyte nuclei in the presence of 0, 0.1, or 1 mM MVM NS2 NES peptide (wt) or a mutated version thereof (mut) as indicated above the lanes. After 0 (lanes 1 and 2) or 90 min (lanes 3 to 10), nuclear (N) and cytoplasmic (C) fractions were obtained and RNAs were purified and analyzed by denaturing PAGE and autoradiography. Positions of the injected RNAs as well as the intron lariat and spliced product of the ftz pre-mRNA are indicated.