U4 spliceosomal RNA (U4 snRNA)

U4 spliceosomal RNA (U4 snRNA) is a non-coding RNA component of the major spliceosome, a large ribonucleoprotein complex responsible for removing introns from pre-messenger RNA (pre-mRNA) in eukaryotes[1][3]. U4 snRNA forms a duplex with U6 snRNA, regulating the catalytic activity of the spliceosome by preventing U6 from adopting its active conformation before the proper stage of splicing[1][2][7]. The dissociation of U4 from U6, mediated by protein Brr2, is essential for activating the spliceosome's catalytic core. U4 is also central to assembling the U4/U6.U5 tri-snRNP, with its structure stabilized by a ring of Sm proteins—a unique feature of spliceosomal snRNAs[3]. While not directly catalyzing splicing, U4 snRNA serves as an RNA chaperone and structural organizer, ensuring correct spliceosome assembly and function. Genetic variants in U4 (e.g., RNU4-2) can disrupt spliceosomal activity and are implicated in rare inherited diseases, although U4 is not a current drug target[9].

Other names

U4 small nuclear RNAU4 snRNARNU4snR14 (in yeast)

Not applicable. No drugs target this RNA.