USB1 : U6 snRNA biogenesis phosphodiesterase 1
Description
The USB1 (U6 snRNA biogenesis phosphodiesterase 1) is a protein-coding gene located on chromosome 16.
The USB1 gene provides instructions for making an enzyme that functions as an RNA exonuclease. RNA exonucleases cut off (cleave) building blocks called nucleotides one at a time from molecules of RNA (a chemical cousin of DNA). This process helps stabilize the RNA and protects it from damage. Specifically, the USB1 enzyme protects a small RNA molecule called U6, which is an essential component of a complex called a spliceosome. The USB1 enzyme also helps transport (chaperones) U6 to the spliceosome and helps it attach (bind) to the proteins in the complex. Spliceosomes process RNA molecules called messenger RNAs (mRNAs) by recognizing and removing regions known as introns and splicing the mRNA molecules back together to provide the blueprint for making proteins. Different versions (isoforms) of the USB1 enzyme are produced in different tissues, where they play various roles. In blood-forming tissues, the USB1 enzyme is thought to be important for the maturation of neutrophils. Neutrophils are a type of white blood cell involved in the immune system. In the skin, the USB1 enzyme is found in pigment-producing cells (melanocytes), cells in the outer layer of the skin called keratinocytes, and structural cells called fibroblasts. Its role in the function of these cells is unknown.
USB1 is a 3'-5' RNA exonuclease that trims the 3' end of oligo(U) and oligo(A) tracts of the pre-U6 small nuclear RNA (snRNA) molecule, resulting in the formation of a mature U6 snRNA 3' end terminated with a 2',3'-cyclic phosphate. This process is essential for preventing U6 snRNA degradation. USB1 also removes uridines from the 3' end of U6atac snRNA and possibly the vault RNA VTRNA1-1.
USB1 is also known as C16orf57, HVSL1, Mpn1, PN, hMpn1, hUsb1.
