title: Association of RNase mitochondrial RNA processing enzyme with ribonuclease P in higher ordered structures in the nucleolus: a possible coordinate role in ribosome biogenesis.
abstract: RNase mitochondrial RNA processing enzyme (MRP) is a nucleolar ribonucleoprotein particle that participates in 5.8S ribosomal RNA maturation in eukaryotes. This enzyme shares a polypeptide and an RNA structural motif with ribonuclease P (RNase P), a nuclear endoribonuclease originally described in the nucleus that processes RNA transcripts to generate their mature 5' termini. Both enzymes are also located in mitochondria. This report further characterizes the relationship between RNase MRP and RNase P. Antisense affinity selection with biotinylated 2'-O-methyl oligoribonucleotides and glycerol gradient fractionation experiments demonstrated that small subpopulations of RNase MRP and RNase P associate with each other in vivo in macromolecular complex, possibly 60-80S preribosomes. This latter notion was supported by fluorescence in situ hybridization experiments with antisense oligonucleotides that localized that RNA components of RNase MRP and RNase P to the nucleolus and to discrete cytoplasmic structures. These findings suggest that small subpopulations of RNase MRP and RNase P are physically associated, and that both may function in ribosomal RNA maturation or ribosome assembly.
authors.affiliation: Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520-8031, USA.
authors.forename: B
authors.initials: B
authors.lastname: Lee
authors.forename: A G
authors.initials: AG
authors.lastname: Matera
authors.forename: D C
authors.initials: DC
authors.lastname: Ward
authors.forename: J
authors.initials: J
authors.lastname: Craft
mesh_terms: D001483:Base Sequence; D002466:Cell Nucleolus / Q000378:metabolism*; D002846:Chromatography, Affinity; D004722:Endoribonucleases / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D017403:In Situ Hybridization; D008928:Mitochondria / Q000378:metabolism; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D016337:RNA, Catalytic / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D012340:RNA, Ribosomal, 5.8S / Q000378:metabolism; D016914:Ribonuclease H; D043262:Ribonuclease P; D012261:Ribonucleoproteins / Q000737:chemistry / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism*
chemical_list: D016337:RNA, Catalytic; D012340:RNA, Ribosomal, 5.8S; D012261:Ribonucleoproteins; D004722:Endoribonucleases; C058330:mitochondrial RNA-processing endoribonuclease; D016914:Ribonuclease H; C468368:RPP14 protein, human; D043262:Ribonuclease P