EXOSC9
Function
Non-catalytic component of the RNA exosome complex which has 3'->5' exoribonuclease activity and participates in a multitude of cellular RNA processing and degradation events. In the nucleus, the RNA exosome complex is involved in proper maturation of stable RNA species such as rRNA, snRNA and snoRNA, in the elimination of RNA processing by-products and non-coding 'pervasive' transcripts, such as antisense RNA species and promoter-upstream transcripts (PROMPTs), and of mRNAs with processing defects, thereby limiting or excluding their export to the cytoplasm. The RNA exosome may be involved in Ig class switch recombination (CSR) and/or Ig variable region somatic hypermutation (SHM) by targeting AICDA deamination activity to transcribed dsDNA substrates. In the cytoplasm, 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, and in RNA surveillance pathways, preventing translation of aberrant mRNAs. It seems to be involved in degradation of histone mRNA. The catalytic inactive RNA exosome core complex of 9 subunits (Exo-9) is proposed to play a pivotal role in the binding and presentation of RNA for ribonucleolysis, and to serve as a scaffold for the association with catalytic subunits and accessory proteins or complexes. EXOSC9 binds to ARE-containing RNAs.
Involvement in disease
Pontocerebellar hypoplasia 1D
PCH1D
An autosomal recessive neurologic disorder with onset at birth or in infancy, and characterized by progressive axonal motor neuronopathy, severe generalized hypotonia, respiratory insufficiency, and cerebellar atrophy. Death in childhood may occur.
None
The disease is caused by variants affecting the gene represented in this entry.
Sequence Similarities
Belongs to the RNase PH family.
Cellular localization
- Cytoplasm
- Nucleus
- Nucleus
- Nucleolus
- Nucleus
- Nucleoplasm
- Colocalizes with SETX in nuclear foci upon induction of transcription-related DNA damage at the S phase (PubMed:24105744).
- Isoform 1
- Nucleus
- Nucleolus
- Isoform 2
- Nucleus
- Nucleolus
- Isoform 3
- Nucleus
- Excluded from the nucleolus.
Alternative names
PMSCL1, EXOSC9, Exosome complex component RRP45, Autoantigen PM/Scl 1, Exosome component 9, P75 polymyositis-scleroderma overlap syndrome-associated autoantigen, Polymyositis/scleroderma autoantigen 1, Polymyositis/scleroderma autoantigen 75 kDa, PM/Scl-75