Figure 3.

The M10 but not the MIX peptide conjugate can inhibit RNA export. (A) The M10 conjugate is a potent inhibitor of DHFR mRNA export. Mixtures containing ³²P-labeled DHFR mRNA, AdML pre-mRNA, U3 snRNA, U1_Sm− snRNA, U5 snRNA, and tRNA_i^Met were coinjected into oocyte nuclei with ≈130 ng per nucleus of the M10 (lanes 1–6) peptide or with buffer only (lanes 7–12). Oocytes were dissected 1.5, 4, and 18 hr after injection, and RNA export was analyzed as in Fig. 1. (B) The MIX conjugate does not interfere with RNA export, even when present in high amounts. Mixtures containing ³²P-labeled DHFR mRNA, U3 snRNA, U1_Sm− snRNA, U5 snRNA, and tRNA_i^Met were coinjected into oocyte nuclei with ≈130 ng per nucleus of the MIX (lanes 1–4) peptide or with buffer alone (lanes 5–8). Oocytes were dissected 1.5 and 4 hr after injection, and RNA export was analyzed as in Fig. 1.