U6 snRNA biogenesis phosphodiesterase 1 (USB1)

U6 snRNA biogenesis phosphodiesterase 1 (USB1) is an **RNA exonuclease** enzyme essential for the processing of the 3′ end of U6 small nuclear RNA (snRNA), a central component of the spliceosome responsible for pre-mRNA splicing. USB1 trims the 3’ end of pre-U6 snRNA transcripts and generates a 2',3'-cyclic phosphate, which is important for snRNP (small nuclear ribonucleoprotein) biogenesis and for the stability and function of U6 snRNA in the spliceosome[1][3][5]. In humans, USB1 also acts on U6atac snRNA, another component of minor spliceosomes. Mutations in USB1 lead to the rare genetic disease *poikiloderma with neutropenia* (PN), typified by skin abnormalities and chronic neutropenia, due to impaired function in blood cell and skin development[1][5]. USB1 is a member of the conserved 2H phosphodiesterase superfamily, is specific for snRNA substrates (notably U6), and is essential for proper RNA processing and spliceosome assembly[3]. No drugs are currently known to target USB1 directly, nor are there established safety concerns outside of genetic inheritance and congenital syndromes. The enzyme does not appear to be a therapeutic drug target in current clinical development.

Other names

C16orf57Mpn1hUsb1Mutated in PN protein 1hMpn1FLJ13154HVSL1PNU6 snRNA phosphodiesterase 13'-5' RNA exonuclease USB1Mutated in poikiloderma with neutropenia protein 1HVSL motif containing 1U six biogenesis 1UPF0406 protein C16orf57

Not applicable, as no approved or experimental drugs directly target USB1