Figure 4.

M2 is an enhancer of DM20 5′ splice site selection. (A) PLP-neo construct and primers used for PCR amplification. Partial sequences of the natural exon 3B (WT) and mutated constructs are shown, underlined are mutations at the DM20 and PLP 5′ splice site and the M2-MT. (B) PLP and DM20 PCR products (35 PCR cycles) from WT and DM20 G>T and DM20 G>T-M2-MT amplified with primers 1 and 2 in RNA extracted from transfected Oli-neu cells. (C) PLP and DM20 PCR products (35 PCR cycles) derived from WT, c.453+2T>C and c.453T>C-M2-MT amplified with primers 1 and 2 in RNA extracted from Oli-neu cells. Plasmid-derived PLP+DM20 PCR product was amplified with primers 3 and 4 and represents the total plasmid-derived PLP/DM20 transcript. Endogenous PLP+DM20 PCR product amplified with primers 1 and 4 is the control for RNA loading.