Inverted Repeat Alu Element (IRAlu)

Alu elements are short, primate-specific transposable elements that make up roughly 10% of the human genome and are frequently found within the untranslated regions of mRNA transcripts. When two Alu elements are present in inverted orientation within the same transcript, their transcribed RNA can fold back on itself to form a long double-stranded RNA hairpin, known as an inverted repeat Alu (IRAlu) structure. Because these structures resemble viral double-stranded RNA, they are prime substrates for both ADAR-mediated RNA editing and recognition by cytosolic dsRNA sensors such as MDA5, making their regulation important for maintaining immune tolerance to the cell’s own transcriptome.