Abstract
ENP1 is an essential Saccharomyces cerevisiae gene encoding a 483 amino acid polypeptide. Enp1 protein is localized in the nucleus and concentrated in the nucleolus. An enp1-1 temperature-sensitive mutant inhibited 35S pre-rRNA early processing at sites A(0), A(1) and A(2) as shown by northern analysis of steady state levels of rRNA precursors. Pulse-chase analysis further revealed that the enp1-1 strain was defective in the synthesis of 20S pre-rRNA and hence 18S rRNA, which led to reduced formation of 40S ribosomal subunits. Co-precipitation analysis revealed that Enp1 was associated with Nop1 protein, as well as with U3 and U14 RNAs, two snoRNAs implicated in early pre-rRNA processing steps. These results suggest a direct role for Enp1 in the early steps of rRNA processing.
Publication types
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Comparative Study
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Alleles
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Amino Acid Sequence
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Binding Sites
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Cell Nucleolus / metabolism
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Green Fluorescent Proteins
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Luminescent Proteins / genetics
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Luminescent Proteins / metabolism
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Molecular Sequence Data
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Mutation
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Nuclear Proteins / genetics
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Nuclear Proteins / metabolism*
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Protein Binding
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RNA Precursors / genetics
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RNA Precursors / metabolism*
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RNA Processing, Post-Transcriptional*
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RNA, Small Nucleolar / metabolism*
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Recombinant Fusion Proteins / genetics
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Recombinant Fusion Proteins / metabolism
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Ribonucleoproteins, Small Nucleolar / metabolism*
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Ribosomes / metabolism*
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Saccharomyces cerevisiae / genetics
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Saccharomyces cerevisiae / growth & development
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Saccharomyces cerevisiae Proteins / genetics
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Saccharomyces cerevisiae Proteins / metabolism*
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Sequence Homology, Amino Acid
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Temperature
Substances
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ENP1 protein, S cerevisiae
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Luminescent Proteins
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NOP1 protein, S cerevisiae
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Nuclear Proteins
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RNA Precursors
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RNA, Small Nucleolar
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Recombinant Fusion Proteins
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Ribonucleoproteins, Small Nucleolar
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Saccharomyces cerevisiae Proteins
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ribonucleoprotein, U3 small nucleolar
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Green Fluorescent Proteins