U1 small nuclear RNA (U1 snRNA)

U1 small nuclear RNA (U1 snRNA; gene: RNU1-1) is a highly conserved, non-coding RNA molecule that constitutes the RNA component of the U1 small nuclear ribonucleoprotein (snRNP) complex[3][5]. U1 snRNP is an essential component of the spliceosome, the molecular machine that removes introns from precursor mRNA (pre-mRNA) during eukaryotic gene expression[1][2][5]. U1 snRNA base-pairs with the 5' splice site of introns, thereby recognizing the exon-intron boundary and facilitating the early assembly of the spliceosome[1][2][5]. The U1 snRNP is composed of U1 snRNA, a heptameric ring of Sm proteins, and U1-specific proteins (U1-70K, U1-A, U1-C)[1]. Beyond its central role in splicing, U1 snRNA also prevents premature polyadenylation of nascent transcripts, a process termed "telescripting," thus safeguarding transcriptome integrity[3]. Mutations, altered expression, or malfunction of U1 snRNA or its RNP complex can result in widespread aberrant splicing and are implicated in diseases such as cancer and certain neurodegenerative disorders[1][3][5]. There are no known clinically approved drugs that selectively target U1 snRNA, although variant or engineered forms have experimental therapeutic utility in correcting some splicing defects[3].

Other names

RNU1-1Rnu1a1U1HU1-1U1A1HSD1RNU1RNU1ARNU1A3RNU1G4U1A3U1G4RNA, U1A small nuclearRNA, U1A3 small nuclearRNA, U1G4 small nuclear

Not directly drug-targeted; however, engineered U1 snRNA variants have been used to correct splicing defects by restoring proper 5' splice site recognition[3].