PRP4

Pre-mRNA processing factor 4 kinase (PRP4K, also known as PRPF4B) is a serine/threonine kinase that regulates pre-mRNA splicing by interacting with spliceosomal components and participating in spliceosome assembly^[1][2]. Mechanistically, PRP4K phosphorylates spliceosomal proteins including PRPF6 and PRPF31, promoting stable integration of the U4/U6-U5 tri-snRNP into the spliceosomal B complex^[2]. PRP4K also associates with transcription-related complexes and contributes to coordination between chromatin regulation and RNA processing^[1]. In disease models, PRP4K has been linked to tumor biology through functions in transcription regulation, the spindle assembly checkpoint, and cellular responses to taxane chemotherapy^[3]. Reduced PRP4K activity promotes aggressive cancer phenotypes in multiple malignancy models, supporting its role as a haploinsufficient tumor suppressor^[3]. Compared with related splicing-associated kinases, PRP4K contains a conserved C-terminal kinase domain and N-terminal regulatory regions that mediate interactions with spliceosomal and nuclear complexes^[1][3]. For experimental applications, PRP4K depletion, genetic perturbation, and kinase activity studies are used to investigate spliceosome activation, cancer cell responses, and RNA processing mechanisms^[2][3]. Selective pharmacological targeting of PRP4K remains an emerging research area because studies have primarily focused on genetic and biochemical approaches to define its cellular functions^[3].