LRE1, LINE-1 retrotransposable element ORF1 protein, L1ORF1p, LINE retrotransposable element 1, LINE1 retrotransposable element 1
LINE-1, also known as L1, is a non-long terminal repeat (non-LTR) retrotransposon with hundreds of thousands of copies in the human genome. Like all non-LTRs, L1 replicates by target-primed reverse transcription (TPRT). The L1 retrotransposon encodes two proteins critical to this process: ORF1p and ORF2p. ORF2p contributes to endonuclease and reverse transcriptase activity, while ORF1p acts as a nucleic acid chaperone that binds RNA. Many types of cancers have been shown to have L1 insertions within tumor suppressor genes, disrupting their expression and contributing to tumorigenesis. While normally silenced, ORF1p is expressed in many types of cancers . Recently, it has been found that ORF1p can become phosphorylated and that this event impacts its ability to promote retrotransposition. This creates a novel dynamic to which the host could actively affect L1 replication through various signaling cascades .
