RP9

Retinitis pigmentosa 9 (autosomal dominant), also known as RP9 or PAP-1, is a is_associated_with::protein which in humans is encoded by the RP9 is_associated_with::gene.

Function
The removal of is_associated_with::introns from nuclear pre-is_associated_with::mRNAs occurs on a complex called a is_associated_with::spliceosome, which is made up of 4 small nuclear ribonucleoprotein (is_associated_with::snRNP) particles and an undefined number of transiently associated splicing factors. The exact role of PAP-1 in splicing is not fully understood, but it is thought that PAP-1 localizes in nuclear speckles containing the splicing factor SC35 and interacts directly with another splicing factor, U2AF35.

Clinical significance
Mutations in PAP1 underlie is_associated_with::autosomal dominant is_associated_with::retinitis pigmentosa mapped to the RP9 gene locus.

Interactions
RP9 has been shown to interact with is_associated_with::U2 small nuclear RNA auxiliary factor 1.