Figure 4.

Analysis of MRP RNA

(A) Analysis of MRP RNA isolated from HEK 293 cells. The left panel shows ethidium-bromide (EtBr)-colored 10% denaturating polyacrylamide gel. The sizing of tRNA, 5S rRNA, and 5.8S rRNA, which were used as size markers, was confirmed by hybridization with corresponding oligonucleotide probes. The right panel shows a hybridization autoradiograph with MRP-RNA oligonucleotide-labeled probes of total RNA, total RNA after lysis of cells with Triton X-100 (1%), crude mtRNA, and mtRNA after mitochondria were treated with an RNase mixture.

(B) Analysis of mitochondrial import of MRP RNA by RNA hybridization. In the Northern blot analysis, total and mtRNA from cultured skin fibroblasts of a control (C) and subject 1 (S1) were hybridized with MRP-RNA, mt-tRNA^Val, and 5.8S rRNA oligonucleotide-labeled probes. Full-sized (265 bp) and processed forms of the MRP RNA (136 bp) are indicated.