Yeast centromere binding protein CBF1, of the helix-loop-helix protein family, is required for chromosome stability and methionine prototrophy.
The centromere and its binding proteins constitute the kinetochore structure of metaphase chromosomes, which is crucial for the high accuracy of the chromosome segregation process. Isolation and analysis of the gene encoding a centromere binding protein from the yeast S. cerevisiae, CBF1, are described in this paper. DNA sequence analysis of the CBF1 gene reveals homology with the transforming protein myc and a family of regulatory proteins known as the helix-loop-helix (HLH) proteins. Disruption of the CBF1 gene caused a decrease in the growth rate, an increase in the rate of chromosome loss/nondisjunction, and hypersensitivity to the antimitotic drug thiabendazole. Unexpectedly, the cbf1 null mutation concomitantly resulted in a methionine auxotrophic phenotype, which suggests that CBF1, like other HLH proteins in higher eukaryotic cells, participates in the regulation of gene expression.
Department of Biochemistry, Stanford University School of Medicine, California 94305-5307.
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D000595:Amino Acid Sequence; D001483:Base Sequence; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D002503:Centromere / Q000502:physiology*; D002875:Chromosomes / Q000502:physiology*; D015825:Chromosomes, Fungal / Q000502:physiology*; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D005838:Genotype; D008715:Methionine / Q000378:metabolism*; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D011505:Protein-Tyrosine Kinases / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000235:genetics; D016271:Proto-Oncogene Proteins c-myc; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D012689:Sequence Homology, Nucleic Acid; D012984:Software; D014158:Transcription, Genetic
D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; C064042:CBF1 protein, S cerevisiae; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D015345:Oligonucleotide Probes; D011518:Proto-Oncogene Proteins; D016271:Proto-Oncogene Proteins c-myc; D029701:Saccharomyces cerevisiae Proteins; D008715:Methionine; D011505:Protein-Tyrosine Kinases