Disease relevance of PRP4

• The eight bases adjacent to the 3' terminus of the RNA 4 fragment are identical in sequence to the eight terminal bases of tyrosine tRNA from Torula utilis and eleven interior bases are identical in sequence to eleven bases encompassing the anticodon region of tyrosine tRNA from Saccharomyces cerevisiae, T. utilis, and Escherichia coli [1].

High impact information on PRP4

• Domains of yeast U4 spliceosomal RNA required for PRP4 protein binding, snRNP-snRNP interactions, and pre-mRNA splicing in vivo [2].
• In its central domain, SOF1 contains a repeated sequence also found in beta-subunits of trimeric G-proteins and the splicing factor PRP4 [3].
• The complete nucleotide sequence of the RNA 4 fragment has been determined by use of standard radiochemical methods [1].
• We have combined oligonucleotide-directed RNase H degradation and immunoprecipitation in a study of the association of the Saccharomyces cerevisiae PRP4 protein with the U4-U6 complex [4].
• Moreover, we found that PRP4 is required early in the spliceosome assembly pathway [5].

Biological context of PRP4

• Twelve of the fourteen single-point mutations that give rise to temperature-sensitive (ts) or null phenotypes are located in the portion of the PRP4 gene that corresponds to the beta-transducin-like region of the protein; the remaining two are located in the central portion of the gene, one of them in an arginine-lysine-rich region [6].
• Expression of PRP3-lacZ and PRP4-lacZ gene fusions is increased in spp41 strains, suggesting that wild-type Spp41p represses expression of PRP3 and PRP4 [7].
• An essential gene in Saccharomyces cerevisiae shares an upstream regulatory element with PRP4 [8].
• In vivo labelling studies using a strain with a mutant allele of the prp4 gene in the genetic background indicate a change in phosphorylation of the Prp1p protein [9].
• To investigate the domain of yPrp4 that directly contacts yPrp3, we introduced deletions in the N-terminal half of yPrp4 and point mutations in the C-terminal half of the molecule, and we tested the resulting prp4 mutants for cell viability and for their ability to interact with yPrp3 [10].

Anatomical context of PRP4

• The PRP4 gene encodes a protein that is a component of the U4/U6 small nuclear ribonucleoprotein particle and is necessary for both spliceosome assembly and pre-mRNA splicing [7].

Associations of PRP4 with chemical compounds

• The biochemical defects of the three thermosensitive prp4 mutants have been examined by immunoprecipitation, native gel electrophoresis, and glycerol gradient centrifugation [11].

Physical interactions of PRP4

• Functional and structural characterization of the prp3 binding domain of the yeast prp4 splicing factor [10].

Other interactions of PRP4

• Neither spp41 nor spp42 suppressors null alleles of prp3 or prp4, indicating that the suppression does not occur via a bypass mechanism [7].
• RNA blot-hybridization analyses coupled with genetic analyses indicated the RNA2+ is coded by a 3.0-kilobase (kb) transcript, RNA4+ is coded by a 1.6-kb transcript, and RNA11+ is coded by a 1.3-kb or a 1.7-kb transcript or both; none of the cloned genes contains detectable introns [12].
• Isolation and characterization of the RNA2+, RNA4+, and RNA11+ genes of Saccharomyces cerevisiae [12].
• The screens also reveal functionally significant interactions with splicing factors, in particular with Prp4 and Prp24, compatible with genetic studies and with the reported association of Lsm proteins with spliceosomal U6 and U4/U6 particles [13].

Analytical, diagnostic and therapeutic context of PRP4

• As an approach to the determination of structure-function relationships in the PRP4 protein, we have isolated more than fifty new alleles of the PRP4 gene through random and site-directed mutagenesis, and have analyzed the phenotypes of many of them [6].
• Immunoprecipitation experiments with anti-PRP4 antibodies were used to demonstrate that PRP4 is a protein of the U4/U6 small nuclear ribonucleoprotein particle (snRNP) [5].
• Immunoprecipitations with the antibodies indicated that the PRP4 protein is associated with the U4/U6 small nuclear ribonucleoprotein particle [14].

References