Genetic evidence for interaction between Cbp1 and specific nucleotides in the 5' untranslated region of mitochondrial cytochrome b mRNA in Saccharomyces cerevisiae.
The cytochrome b (COB) gene is encoded by the mitochondrial genome; however, its expression requires the participation of several nuclearly encoded protein factors. The yeast Cbp1 protein, which is encoded by the nuclear CBP1 gene, is required for the stabilization of COB mRNA. A previous deletion analysis identified an 11-nucleotide-long sequence within the 5' untranslated region of COB mRNA that is important for Cbp1-dependent COB mRNA stability. In the present study, site-directed mutagenesis experiments were carried out to define further the features of this cis element. The CCG sequence within this region was shown to be necessary for stability. A change in residue 533 of Cbp1 from aspartate to tyrosine suppresses the effects of a single-base change in the CCG element. This is strong genetic evidence that the nuclearly encoded Cbp1 protein recognizes and binds directly to the sequence containing CCG and thus protects COB mRNA from degradation.
Chen
W
W
Department of Biochemistry, University of Arizona, Tucson 85721, USA.
Dieckmann
C L
CL
D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D003573:Cytochrome b Group / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D008928:Mitochondria / Q000235:genetics*; D008957:Models, Genetic; D016297:Mutagenesis, Site-Directed; D009690:Nucleic Acid Conformation; D010101:Oxygen Consumption / Q000235:genetics; D016133:Polymerase Chain Reaction; D011485:Protein Binding; D014176:Protein Biosynthesis; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D017422:Sequence Analysis, DNA; D013489:Suppression, Genetic
D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; C064042:CBF1 protein, S cerevisiae; D003573:Cytochrome b Group; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D012331:RNA, Fungal; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins