Biomaterial Database

Effect of initiation factor eIF-5A depletion on protein synthesis and proliferation of Saccharomyces cerevisiae. 1994

H A Kang, and J W Hershey

Department of Biological Chemistry, School of Medicine, University of California, Davis 95616.

Eukaryotic translation initiation factor eIF-5A (formerly eIF-4D) is thought to function in protein synthesis by promoting synthesis of the first peptide bond because it stimulates methionyl-puromycin formation in vitro. eIF-5A is encoded by two genes (TIF51A and TIF51B) in Saccharomyces cerevisiae; the protein and its hypusine modification are essential for cell viability. To analyze the factor's function in vivo, we expressed from the repressible GAL promoter a functional but unstable eIF-5A fusion protein (R-eIF-5A) with an NH2-terminal arginine which is subject to rapid turnover through the NH2-terminal end rule proteolytic pathway. When the conditional mutant strain is shifted from galactose to glucose medium, the rapid disappearance of R-eIF-5A protein occurs within one generation, causing an immediate inhibition of cell growth. However, eIF-5A-depleted cells synthesize protein at about 70% of the wild type rate and exhibit only a slight change in polysome profiles reflecting a subtle defect in a late step of translation initiation. These results suggest that the activity of eIF-5A may not be absolutely essential for general protein synthesis. Rather, eIF-5A may be selectively required for translation of certain mRNAs and/or may be involved in some other aspect of cell metabolism.

UI	MeSH Term	Description	Entries
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D010442	Peptide Chain Initiation, Translational	A process of GENETIC TRANSLATION whereby the formation of a peptide chain is started. It includes assembly of the RIBOSOME components, the MESSENGER RNA coding for the polypeptide to be made, INITIATOR TRNA, and PEPTIDE INITIATION FACTORS; and placement of the first amino acid in the peptide chain. The details and components of this process are unique for prokaryotic protein biosynthesis and eukaryotic protein biosynthesis.	Chain Initiation, Peptide, Translational,Protein Biosynthesis Initiation,Protein Chain Initiation, Translational,Protein Translation Initiation,Translation Initiation, Genetic,Translation Initiation, Protein,Translational Initiation, Protein,Translational Peptide Chain Initiation,Biosynthesis Initiation, Protein,Genetic Translation Initiation,Initiation, Genetic Translation,Initiation, Protein Biosynthesis,Initiation, Protein Translation,Initiation, Protein Translational,Protein Translational Initiation
D010448	Peptide Initiation Factors	Protein factors uniquely required during the initiation phase of protein synthesis in GENETIC TRANSLATION.	Initiation Factors,Initiation Factor,Factors, Peptide Initiation,Initiation Factors, Peptide
D002455	Cell Division	The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.	M Phase,Cell Division Phase,Cell Divisions,Division Phase, Cell,Division, Cell,Divisions, Cell,M Phases,Phase, Cell Division,Phase, M,Phases, M
D002470	Cell Survival	The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.	Cell Viability,Cell Viabilities,Survival, Cell,Viabilities, Cell,Viability, Cell
D005656	Fungal Proteins	Proteins found in any species of fungus.	Fungal Gene Products,Fungal Gene Proteins,Fungal Peptides,Gene Products, Fungal,Yeast Proteins,Gene Proteins, Fungal,Peptides, Fungal,Proteins, Fungal
D000097574	Eukaryotic Translation Initiation Factor 5A	A component of eukaryotic initiation factor 5A that is involved in the elongation, termination, and stimulation of peptide bond formation. This factor is essential for cell proliferation	Eukaryotic Initiation Factor-4D,eIF-4D,eIF-5A,eIF5A protein
D001483	Base Sequence	The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.	DNA Sequence,Nucleotide Sequence,RNA Sequence,DNA Sequences,Base Sequences,Nucleotide Sequences,RNA Sequences,Sequence, Base,Sequence, DNA,Sequence, Nucleotide,Sequence, RNA,Sequences, Base,Sequences, DNA,Sequences, Nucleotide,Sequences, RNA
D012441	Saccharomyces cerevisiae	A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.	Baker's Yeast,Brewer's Yeast,Candida robusta,S. cerevisiae,Saccharomyces capensis,Saccharomyces italicus,Saccharomyces oviformis,Saccharomyces uvarum var. melibiosus,Yeast, Baker's,Yeast, Brewer's,Baker Yeast,S cerevisiae,Baker's Yeasts,Yeast, Baker
D016601	RNA-Binding Proteins	Proteins that bind to RNA molecules. Included here are RIBONUCLEOPROTEINS and other proteins whose function is to bind specifically to RNA.	Double-Stranded RNA-Binding Protein,Double-Stranded RNA-Binding Proteins,ds RNA-Binding Protein,RNA-Binding Protein,ds RNA-Binding Proteins,Double Stranded RNA Binding Protein,Double Stranded RNA Binding Proteins,Protein, Double-Stranded RNA-Binding,Protein, ds RNA-Binding,RNA Binding Protein,RNA Binding Proteins,RNA-Binding Protein, Double-Stranded,RNA-Binding Protein, ds,RNA-Binding Proteins, Double-Stranded,ds RNA Binding Protein