InterPro domain: IPR044092

PRP4 phosphorylates a number of factors involved in the formation of active spliceosomes, which catalyse pre-mRNA splicing. It phosphorylates PRP6 and PRP31, components of the U4/U6-U5 tri-small nuclear ribonucleoprotein (snRNP), during spliceosomal complex formation [ 1 , 2 ]. In fission yeast, PRP4 phosphorylates the splicing factor PRP1 (U5-102 kD in mammals). Thus, PRP4 plays a key role in regulating spliceosome assembly and pre-mRNA splicing [ 3 , 4 ]. It also plays an important role in mitosis by acting as a spindle assembly checkpoint kinase that is required for chromosome alignment and the recruitment of the checkpoint proteins MPS1, MAD1, and MAD2 at kinetochores [ 5 ].

This entry represents the catalytic domain of PRP4.

1. Mammalian PRP4 kinase copurifies and interacts with components of both the U5 snRNP and the N-CoR deacetylase complexes. Mol. Cell. Biol. 22, 5141-56
2. Human PRP4 kinase is required for stable tri-snRNP association during spliceosomal B complex formation. Nat. Struct. Mol. Biol. 17, 216-21
3. Fission yeast Prp4p kinase regulates pre-mRNA splicing by phosphorylating a non-SR-splicing factor. EMBO Rep. 2, 35-41
4. Multiple genetic and biochemical interactions of Brr2, Prp8, Prp31, Prp1 and Prp4 kinase suggest a function in the control of the activation of spliceosomes in Schizosaccharomyces pombe. Curr. Genet. 48, 151-61
5. PRP4 is a spindle assembly checkpoint protein required for MPS1, MAD1, and MAD2 localization to the kinetochores. J. Cell Biol. 179, 601-9