Merck, MABC1152, Anti-LINE-1 ORF1p Antibody, clone 4H1

LINE-1 retrotransposable element ORF1 protein (UniProt: Q9UN81; also known L1ORF1p, LINE retrotransposable element 1, LINE1 retrotransposable element 1) is encoded by the LIRE1 (also known as LRE1) gene in human. LINE1-ORF 1P belongs to the transposase 22 family. It is mainly cytoplasmic protein and is enriched in stress granules, but may rarely be detected in the nucleolus. It contains a coiled coil domain that mediates its homotrimerization. The RNA recognition motif (RRM) the C-terminal domain are required for its proper RNA-binding activity. LINE1-ORF 1P is a nucleic acid-binding protein which is essential for retrotransposition of LINE-1 elements in the genome. It is also reported to function as a nucleic acid chaperone binding its own transcript and therefore preferentially mobilizing the transcript from which they are encoded. Retrotransposition is a shown to be a complex process that involves transcription of the LINE1, transport of its RNA to the cytoplasm, translation of the bicistronic RNA, formation of a ribonucleoprotein particle, its re-import to the nucleus and then target-primed reverse transcription at the integration site. Somatic LINE1 insertions are rare in most tissues, but are found in brain, testis, and many cancer types and have been implicated in carcinogenesis. Its expression is consistently detected in p53 mutant tumors, but, little or no expression is detected in Wilms tumors that were normal for p53. (Ref.: Goodier, JL et al. (2013). Nucleic Acids Res. 41(15): 7401-7419).