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Abstract
B2 SINEs (Short Interspersed Nuclear Elements) are moderately repetitive retrotransposons transcribed by RNA Polymerase III. B2 RNA transcription is upregulated during stressful events—such as apoptosis in sympathetic neuronal cells and heat-shock in embryonic mouse fibroblast cells. Though this upregulation is correlated with a marked decrease of Pol II-transcribed mRNA levels, the function of B2 RNAs remains largely unknown. Recent findings with NIH3T3 cells determined that B2 RNAs repress the Pol II transcription machinery by binding to core Pol II during heat-shock. Here we asked whether the Pol II is a target of B2 RNAs during apoptosis triggered by NGF (Nerve Growth Factor) withdrawal in neuronal PC12 cells through RT-PCR of co-precipitated B2 RNAs and through Northern Blot. We precipitated Pol II from nuclear lysates of apoptotic neuronal PC12 cells and analyzed co-precipitated RNAs but failed to show a clear association between B2 RNAs and Pol II.
