UPF3B
Function
Involved in nonsense-mediated decay (NMD) of mRNAs containing premature stop codons by associating with the nuclear exon junction complex (EJC) and serving as link between the EJC core and NMD machinery. Recruits UPF2 at the cytoplasmic side of the nuclear envelope and the subsequent formation of an UPF1-UPF2-UPF3 surveillance complex (including UPF1 bound to release factors at the stalled ribosome) is believed to activate NMD. In cooperation with UPF2 stimulates both ATPase and RNA helicase activities of UPF1. Binds spliced mRNA upstream of exon-exon junctions. In vitro, stimulates translation; the function is independent of association with UPF2 and components of the EJC core.
Involvement in disease
Intellectual developmental disorder, X-linked, syndromic 14
MRXS14
A disorder characterized by significantly below average general intellectual functioning associated with impairments in adaptive behavior and manifested during the developmental period. MRXS14 patients manifest intellectual disability associated with other variable signs such as autistic features, slender build, poor musculature, long, thin face, high-arched palate, high nasal bridge, and pectus deformities.
None
The disease is caused by variants affecting the gene represented in this entry.
Sequence Similarities
Belongs to the RENT3 family.
Tissue Specificity
Expressed in testis, uterus, prostate, heart, muscle, brain, spinal cord and placenta.
Cellular localization
- Nucleus
- Cytoplasm
- Shuttling between the nucleus and the cytoplasm.
Alternative names
RENT3B, UPF3X, UPF3B, Regulator of nonsense transcripts 3B, Nonsense mRNA reducing factor 3B, Up-frameshift suppressor 3 homolog B, Up-frameshift suppressor 3 homolog on chromosome X, hUpf3B, hUpf3p-X