Figure 5.

TDP-43 regulates proapototic BH3-only, Trp53 and Cdkn1a mRNA expression. (a) TDP-43 and TDP-43^A315T expression in neural progenitors increases Trp53 and Cdkn1a mRNA levels, analyzed by quantitative RT-PCR analysis. TDP-43^∆RRM1expression does not affect Trp53 and Cdkn1a mRNA levels. (b) TDP-43 and TDP-43^A315T expression in neural progenitors results in increased level of activated, phosphorylated p53 protein and total p53 protein. (c) TDP-43 and TDP-43^A315T expression in neural progenitors increases mRNA levels of the proapoptotic BH3-only proteins Bbc3 (PUMA) and Bax, but not the antiapoptotic factor Bcl2. TDP-43^∆RRM1expression does not affect Bbc3, Bax or Bcl-2 mRNA levels. (d) Pharmacological inhibition of p53 reduces TDP-43 and TDP-43^A315T induced Trp53 and Cdkn1a mRNA levels but does not affect endogenous Tardbp mRNA expression, analyzed by quantitative RT-PCR analysis. Values are shown as relative to non-treated, standardized to β-actin. (e) TDP-43 binds endogenous Tardbp and Cdkn1a but not Trp53 mRNAs. Quantitative RT-PCR analysis of Tardbp, Cdkn1a, Trp53 and β-actin transcripts CLIPed together with TDP-43 from neural progenitors. Values are fold enrichment over control CLIPed (flag-GFP) transcripts. Statistical analysis of CLIPed products corrected relative to input RNA concentrations compared to flag-GFP CLIPed samples. Agarose gel analysis of the amplicons is shown in Supplementary Fig. 6a.