NOP3 is an essential yeast protein which is required for pre-rRNA processing

• Published in: The Journal of cell biology Vol. 119; no. 4; pp. 737 - 747
• Main Authors: Russell, I.D. (European Molecular Biology Laboratory, Heidelberg, Germany), Tollervey, D
• Format: Journal Article
• Language: English
• Published: New York, NY Rockefeller University Press 01.11.1992; The Rockefeller University Press
• Subjects: Amino Acid Sequence; Amino acids; Antibodies; ARN RIBOSOMAL; ARN RIBOSOMIAL; Base Sequence; Biological and medical sciences; Cell Nucleolus - chemistry; Cell Nucleus - chemistry; Cellular biology; Cloning, Molecular; DNA; Fluorescent Antibody Technique; Fundamental and applied biological sciences. Psychology; Fungal Proteins - chemistry; Fungal Proteins - genetics; Fungal Proteins - metabolism; GENE; GENES; Genetic hybridization; Genomics; IMMUNOLOGIE; INMUNOLOGIA; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Molecular Weight; Mutation; Nuclear Proteins - chemistry; Nuclear Proteins - genetics; Nuclear Proteins - metabolism; NUCLEOLE; NUCLEOLOS; NUCLEOPROTEINAS; NUCLEOPROTEINE; NUCLEOTIDE; NUCLEOTIDOS; Proteins; Ribonucleic acid; Ribosomes; Ribosomes - metabolism; RNA; RNA Precursors - metabolism; RNA Processing, Post-Transcriptional; RNA, Fungal - metabolism; RNA-Binding Proteins; SACCHAROMYCES CEREVISIAE; Saccharomyces cerevisiae - chemistry; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - physiology; Saccharomyces cerevisiae Proteins; Small nuclear RNA; Small nucleolar RNA; Transcription. Transcription factor. Splicing. Rna processing; Yeast; Yeasts; Fungi; Proteins; C terminal-Sequence; Arginine; Cell nucleus; Ascomycetes; Nucleolus; Glycine; Localization; Saccharomyces cerevisiae; Aminoacid sequence; Thallophyta
• ISSN: 0021-9525; 1540-8140
• DOI: 10.1083/jcb.119.4.737

The four nucleolar proteins NOP1, SSB1, GAR1, and NSR1 of Saccharomyces cerevisiae share a repetitive domain composed of repeat units rich in glycine and arginine (GAR domain). We have cloned and sequenced a fifth member of this family, NOP3, and shown it to be essential for cell viability. The NOP3 open reading frame encodes a 415 amino acid protein with a predicted molecular mass of 45 kD, containing a GAR domain and an RNA recognition motif. NOP3-specific antibodies recognize a 60-kD protein by SDS-PAGE and decorate the nucleolus and the surrounding nucleoplasm. A conditional lethal mutation, GAL::nop3, was constructed; growth of the mutant strain in glucose medium represses NOP3 expression. In cells depleted of NOP3, production of cytoplasmic ribosomes is impaired. Northern analysis and pulse-chase labeling indicate that pre-rRNA processing is inhibited at the late steps, in which 27SB pre-rRNA is cleaved to 25S rRNA and 20S pre-rRNA to 18S rRNA