EXOSC8 Protein, Human

EXOSC8, a non-catalytic component of the RNA exosome complex, plays a crucial role in 3'->5' exoribonuclease activity and participates in various cellular RNA processing and degradation events. Within the nucleus, the RNA exosome complex is integral to the maturation of stable RNA species like rRNA, snRNA, and snoRNA, while simultaneously eliminating RNA processing by-products, non-coding 'pervasive' transcripts such as antisense RNA species and promoter-upstream transcripts (PROMPTs), and mRNAs with processing defects, preventing their export to the cytoplasm. The RNA exosome may contribute to Ig class switch recombination (CSR) and/or Ig variable region somatic hypermutation (SHM) by directing AICDA deamination activity toward transcribed dsDNA substrates. In the cytoplasm, EXOSC8, as part of the RNA exosome complex, is involved in general mRNA turnover and specifically degrades inherently unstable mRNAs containing AU-rich elements (AREs) within their 3' untranslated regions. Additionally, it participates in RNA surveillance pathways, preventing the translation of aberrant mRNAs, and appears to play a role in the degradation of histone mRNA. The catalytically inactive RNA exosome core complex of 9 subunits (Exo-9) is suggested to play a pivotal role in binding and presenting RNA for ribonucleolysis, serving as a scaffold for the association with catalytic subunits and accessory proteins or complexes. EXOSC8 specifically binds to ARE-containing RNAs, emphasizing its diverse roles in RNA-related processes. Furthermore, it has been identified to interact with the outer membrane protein opap from Neisseria gonorrhoeae.