Abstract
To identify new genes involved in 3'-end formation of mRNAs in Saccharomyces cerevisiae, we carried out a screen for synthetic lethal mutants with the conditional poly(A) polymerase allele, pap1-7. Five independent temperature-sensitive mutations called Icp1 to Icp5 (for lethal with conditional pap1 allele) were isolated. Here, we describe the characterization of the essential gene LCP5 which codes for a protein with a calculated molecular mass of 40.8 kD. Unexpectedly, we found that mutations in LCP5 caused defects in pre-ribosomal RNA (pre-rRNA) processing, whereas mRNA 3'-end formation in vitro was comparable to wild-type. Early cleavage steps (denoted A0 to A2) that lead to the production of mature 18S rRNA were impaired. In vivo depletion of Lcp5p also inhibited pre-rRNA processing. As a consequence, mutant and depleted cells showed decreased levels of polysomes compared to wild-type cells. Indirect immunofluorescence indicated a predominant localization of Lcp5p in the nucleolus. In addition, antibodies directed against Lcp5p specifically immunoprecipitated the yeast U3 snoRNA snR17, suggesting that the protein is directly involved in pre-rRNA processing.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Alleles*
-
Amino Acid Sequence
-
Basic-Leucine Zipper Transcription Factors
-
DNA-Binding Proteins / genetics
-
Fungal Proteins / genetics
-
Fungal Proteins / metabolism
-
Genes, Essential / genetics
-
Genes, Fungal / genetics*
-
Genes, Lethal / genetics
-
Molecular Sequence Data
-
Mutagenesis
-
Nuclear Proteins / genetics*
-
Nuclear Proteins / metabolism
-
Pancreatitis-Associated Proteins
-
Phenotype
-
Polynucleotide Adenylyltransferase / genetics*
-
Polyribosomes / metabolism
-
Protein Biosynthesis / genetics
-
RNA Processing, Post-Transcriptional*
-
RNA, Fungal / genetics
-
RNA, Fungal / metabolism
-
RNA, Ribosomal, 18S / genetics*
-
RNA, Ribosomal, 18S / metabolism
-
RNA, Small Nuclear / metabolism
-
RNA-Binding Proteins*
-
Ribosomes / metabolism
-
Saccharomyces cerevisiae / genetics*
-
Saccharomyces cerevisiae Proteins*
-
Schizosaccharomyces pombe Proteins
Substances
-
Basic-Leucine Zipper Transcription Factors
-
DNA-Binding Proteins
-
FAL1 protein, S cerevisiae
-
Fungal Proteins
-
Lcp5 protein, S cerevisiae
-
Nuclear Proteins
-
Pancreatitis-Associated Proteins
-
Pap1 protein, S pombe
-
REG3A protein, human
-
RNA, Fungal
-
RNA, Ribosomal, 18S
-
RNA, Small Nuclear
-
RNA-Binding Proteins
-
Saccharomyces cerevisiae Proteins
-
Schizosaccharomyces pombe Proteins
-
Polynucleotide Adenylyltransferase