U4/U6 small nuclear ribonucleoprotein Prp3

PRPF3 encodes U4/U6 small nuclear ribonucleoprotein Prp3, a component of the U4/U6-U5 tri-snRNP complex essential for pre-mRNA splicing and spliceosome assembly (UniProt: O43395). The protein facilitates formation of the precatalytic spliceosome B complex, a critical step in splicing regulation.

PRPF3 is primarily implicated in retinal disease; mutations cause retinitis pigmentosa 18, a progressive photoreceptor dystrophy (UniProt: O43395). The protein's spliceosome functions are broadly relevant across tissues, including neurons, where splicing dysregulation has been proposed as a mechanism in neurodegenerative disease.

PRPF3 carries a disease:ad tag reflecting potential Alzheimer's Disease relevance. In post-mortem AD brain proteomics (TMT-labeled subcellular fractionation, 4 fractions), PRPF3 showed ambiguous regulation with a mean log2 fold-change of +0.047 across 2 fractions, indicating minimal and inconsistent change relative to age-matched controls (Chaparral AD proteomics). This weak, direction-ambiguous signal suggests PRPF3 is not a major proteome-level signature protein in AD brain.