EXOSC1
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. EXOSC1 as peripheral part of the Exo-9 complex stabilizes the hexameric ring of RNase PH-domain subunits through contacts with EXOSC6 and EXOSC8.
Involvement in disease
Pontocerebellar hypoplasia 1F
PCH1F
A form of pontocerebellar hypoplasia, a disorder characterized by structural defects of the pons and cerebellum, evident upon brain imaging. PCH1F is an autosomal recessive form characterized by hypotonia, global developmental delay, poor overall growth, and dysmorphic facial features. Brain imaging shows pontocerebellar hypoplasia, thin corpus callosum, cerebral atrophy, and delayed myelination.
None
The disease is caused by variants affecting the gene represented in this entry.
Sequence Similarities
Belongs to the CSL4 family.
Cellular localization
- Nucleus
- Nucleolus
- Nucleus
- Cytoplasm
Alternative names
CSL4, CGI-108, EXOSC1, Exosome complex component CSL4, Exosome component 1