Enrichment of processed pseudogene transcripts in L1-ribonucleoprotein particles

We explored the RNA binding properties of LINE-1 ORF1p, both free and in the L1 RNP, using a recently developed photoactivatable-ribonucleoside-enhanced crosslinking and immunoprecipitation technique (PAR-CLIP) to comprehensively identify ORF1p binding sites in the transcriptome of human cells (HEK293T). Our results show that ORF1p binds to a wide range of cellular mRNAs, with an enrichment for binding at the 3’ UTR. Our data also show that ORF1p binds very strongly with retrotransposable RNA, i.e., L1, Alu and SVA. PAR-CLIP analysis of L1 RNPs and free ORF1p RNA binding profiles, comparison to HuR RNA binding profile