FIG. 1.

EB2 inhibits the expression of differentially spliced polyadenylated RNAs expressed from pBLCAT2. (A) Diagrams of the expected processed RNAs generated from plasmids pBLCAT2 and pSV2β. The genetic contents of the pre-mRNAs initiated at the tk promoter (pTK) in pBLCAT2 and at the early SV40 promoter in pSV2β (pSV40E) are indicated. The CAT ORF in pBLCAT2 and the rabbit β-globin sequences in pSV2β are shaded. DNA probes 1 and 2 were used for the Northern blot analysis shown in panel B. The deadenylation and cleavage of the expected processed RNAs by RNase H in the presence of oligo(dT) or oligo(dT) plus oligo(H) and the lengths of the expected RNase H-treated RNA products are also indicated. (B) Northern blot analysis of the RNAs transiently expressed in HeLa cells from plasmids pBLCAT2 (lanes 1 to 5) and pSV2β (lanes 6 to 9). The plasmids transfected, the proteins expressed, and the RNase H treatments are indicated above the panels. The ³²P-labeled DNA probes used are indicated below the panels. M(Kb), molecular size markers (number of kilobases).