Fig. 6.

iSINEs do not destabilize mRNA but interfere with RNA polymerase II (polII). a mRNA transcription was blocked using Actinomycin D. Subsequently, mRNAs were collected 0, 1, and 2 h after transcriptional inhibition and mRNA levels were determined by RT-qPCR. b The Pol II-immunoprecipitated DNA was analyzed by real time PCR. Three different regions of the reporter gene—the 5′ coding region (A), stop codon (B), and near poly(A) signal (C)—were amplified. The amplicons are shown as grey boxes. Reporters harboring the c Nicn1 1SINE, iSINE, and dSINE or the d Znf708 1SINE, piSINE, and pdSINE were transfected in U2OS cells and the Pol II density along the genes was measured. Clearly, Pol II density decreases downstream of stable iSINEs. Error bars indicate standard deviation. Asterisks indicate p values calculated with Student’s t-test: *p < 0.05, **p < 0.005, ***p < 0.0005