EXOSC3 : exosome component 3
Description
The EXOSC3 (exosome component 3) is a protein-coding gene located on chromosome 9.
The EXOSC3 gene provides instructions for making a protein known as exosome component 3. This protein is a part of the RNA exosome complex, which processes and breaks down RNA molecules within cells. The RNA exosome is vital for normal cellular function, and studies suggest that exosome component 3 is crucial for the development and growth of specific brain regions, particularly the cerebellum, and for the survival of motor neurons in the spinal cord.
The EXOSC3 protein is a non-catalytic component of the RNA exosome complex, which plays a crucial role in RNA processing and degradation. It contributes to the proper maturation of stable RNA species such as ribosomal RNA (rRNA), small nuclear RNA (snRNA), and small nucleolar RNA (snoRNA) in the nucleus. It also participates in eliminating RNA processing byproducts and non-coding transcripts like antisense RNA and promoter-upstream transcripts (PROMPTs), as well as mRNAs with processing defects, limiting their export to the cytoplasm. The RNA exosome may be involved in immunoglobulin class switch recombination (CSR) and/or immunoglobulin variable region somatic hypermutation (SHM) by targeting activation-induced cytidine deaminase (AICDA) deamination activity to transcribed double-stranded DNA substrates. In the cytoplasm, the EXOSC3 protein is involved in general mRNA turnover and specifically degrades unstable mRNAs containing AU-rich elements (AREs) within their 3' untranslated regions. It also plays a role in RNA surveillance pathways, preventing the translation of aberrant mRNAs. It seems to be involved in the degradation of histone mRNA. The catalytically inactive RNA exosome core complex, known as Exo-9, composed of nine subunits, is believed to bind and present RNA for ribonucleolysis and serve as a scaffold for associating with catalytic subunits and accessory proteins or complexes. EXOSC3, as a peripheral component of the Exo-9 complex, stabilizes the hexameric ring of RNase PH-domain subunits through interactions with EXOSC9 and EXOSC5.
EXOSC3 is also known as CGI-102, PCH1B, RRP40, Rrp40p, bA3J10.7, hRrp-40, p10.
