EXOSC8

This gene encodes a 3'-5' exoribonuclease that specifically interacts with mRNAs containing AU-rich elements. The encoded protein is part of the exosome complex that is important for the degradation of numerous RNA species. A pseudogene of this gene is found on chromosome 6. [provided by RefSeq]

Full Name

exosome component 8

Research Area

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. EXOSC8 binds to ARE-containing RNAs.

Biological Process

Exonucleolytic catabolism of deadenylated mRNA Source: GO_Central
Exonucleolytic trimming to generate mature 3'-end of 5.8S rRNA from tricistronic rRNA transcript (SSU-rRNA, 5.8S rRNA, LSU-rRNA) Source: GO_Central
Nuclear mRNA surveillance Source: GO_Central
Nuclear polyadenylation-dependent mRNA catabolic process Source: GO_Central
Nuclear polyadenylation-dependent rRNA catabolic process Source: GO_Central
Nuclear polyadenylation-dependent tRNA catabolic process Source: GO_Central
Nuclear-transcribed mRNA catabolic process, exonucleolytic, 3'-5' Source: GO_Central
rRNA catabolic process Source: GO_Central
U1 snRNA 3'-end processing Source: GO_Central
U4 snRNA 3'-end processing Source: GO_Central
U5 snRNA 3'-end processing Source: GO_Central

Cellular Location

Nucleolus; Nucleus; Cytoplasm

Involvement in disease

Pontocerebellar hypoplasia 1C (PCH1C):
The disease is caused by variants affecting the gene represented in this entry. EXOSC8 dysfunction causes myelin disruption through an imbalanced supply of myelin proteins due to dysregulation of their ARE-containing mRNAs (PubMed:24989451). A severe autosomal recessive neurodegenerative disease characterized by cerebellar and corpus callosum hypoplasia, abnormal myelination of the central nervous system, and spinal motor neuron disease. Affected individuals manifest failure to thrive, severe muscle weakness, spasticity and psychomotor retardation. Vision and hearing are impaired.