U1C23

U1C23 is a protein subunit associated with the U1 small nuclear ribonucleoprotein particle (U1 snRNP), a component of the spliceosome. It is a 23 kDa protein predicted to contain a coiled-coil region and an acidic C-terminal tail, and it interacts with core U1 components such as U1-70K and U1A.

It participates in the early assembly of the U1 snRNP, helping stabilize U1 snRNA and promoting correct 5' splice site recognition during pre-mRNA splicing. The protein is predominantly nuclear, with enrichment in nuclear speckles and a dynamic distribution that changes with transcriptional activity.

The U1C23 gene is located in a region corresponding to vertebrate chromosome homologs in model organisms, and orthologs are detected across most vertebrates and many eukaryotes, indicating conservation of the U1C23 family. Expression is constitutive with tissue-specific modulation by splicing factors; post-translational modifications such as phosphorylation may influence interaction with U1 snRNP partners.

No direct disease associations have been established for U1C23; it is used primarily in basic research to study U1 snRNP assembly and spliceosome function. See also U1 snRNP and Spliceosome.