Figure 5.

Splicing changes in cells expressing mutated Ataxin3 fragment with 69 glutamine residues. (A) Diagram of the pEGFP-mutATXN3 construct used to generate SK-N-MC cell lines expressing 69 CAG repeats in protein coding region. The stop codon of the EGFP protein was removed and a cDNA sequence of mutant human ATXN3 containing 69 CAG repeats was inserted in frame at the 3′-terminus to induce expression of EGFP-mutant Ataxin 3 fusion protein containing 69 Q-residues. (B) RT–PCR products of the alternative splicing of SERCA1, CLCN1 and control ATE1 gene. Quantification of the results is presented in the graphs as the percentage of splice products that include or exclude the indicated exons. The experiments repeated three times were carried out in three transgenic SK-N-MC lines (mutATXN3 1–3). *P = (0.05; 0.001), **P < 0.001 compared with the untreated cells (control). SK-N-MC cells with MBNL1 siRNA knocked down were used as a positive control (siMBNL1).