EXOSC6
Description
The EXOSC6 (exosome component 6) is a protein-coding gene located on chromosome 16.
The EXOSC6 gene encodes the Exosome complex exonuclease MTR3 protein, a subunit of the multisubunit exosome complex. This complex is involved in mRNA degradation and is similar in structure to its yeast counterpart. EXOSC6 is homologous to the yeast Mtr3 protein. While its precise function is unknown, studies using a cell-free RNA decay system have shown that the exosome is necessary for the rapid degradation of unstable mRNAs containing AU-rich elements (AREs), but not for poly(A) shortening. The exosome does not directly recognize ARE-containing mRNAs, but relies on ARE-binding proteins that interact with the exosome and recruit it to unstable mRNAs, promoting their rapid degradation. EXOSC6 has been shown to interact with other exosome components, including Exosome component 7, Exosome component 8, and Exosome component 1.
EXOSC6 is a non-catalytic component of the RNA exosome complex, a multi-protein machinery involved in various RNA processing and degradation events within the cell. The exosome complex exhibits 3'-to-5' exoribonuclease activity, essential for numerous cellular functions. In the nucleus, EXOSC6 contributes to the proper maturation of stable RNA species like ribosomal RNA (rRNA), small nuclear RNA (snRNA), and small nucleolar RNA (snoRNA). It also participates in eliminating RNA processing byproducts and non-coding transcripts such as antisense RNA and promoter-upstream transcripts (PROMPTs). Additionally, EXOSC6 plays a role in the quality control of mRNA, targeting mRNAs with processing defects and limiting their export to the cytoplasm. In the cytoplasm, EXOSC6 participates in general mRNA turnover, specifically degrading inherently unstable mRNAs containing AU-rich elements (AREs) in their 3' untranslated regions. It also functions in RNA surveillance pathways, preventing the translation of aberrant mRNAs. EXOSC6 is part of the catalytically inactive RNA exosome core (Exo-9) complex, which binds and presents RNA for degradation by associated catalytic subunits like EXOSC10 and DIS3/DIS3L. This core complex serves as a scaffold for the interaction with catalytic subunits and accessory proteins or complexes.
EXOSC6 is also known as EAP4, MTR3, Mtr3p, hMtr3p, p11.
