Assembly of the mitochondrial membrane system. CBP1, a yeast nuclear gene involved in 5' end processing of cytochrome b pre-mRNA

• Published in: The Journal of biological chemistry Vol. 259; no. 8; pp. 4722 - 4731
• Main Authors: Dieckmann, C L, Koerner, T J, Tzagoloff, A
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Elsevier Inc 25.04.1984; American Society for Biochemistry and Molecular Biology
• Subjects: Base Sequence; Biological and medical sciences; Cell structures and functions; Cytochrome b Group - genetics; Fundamental and applied biological sciences. Psychology; Genes; Genes, Fungal; Genotype; Intracellular Membranes - physiology; Mitochondria - physiology; Mitochondria and cell respiration; Molecular and cellular biology; Mutation; Nucleic Acid Hybridization; Nucleic Acid Precursors - genetics; RNA Precursors; RNA, Messenger - genetics; Saccharomyces cerevisiae - genetics; Transcription, Genetic; Mitochondria; Cytochrome b; Messenger RNA; Molecular assembly; Membrane; Mutation; Gene expression; Saccharomyces cerevisiae
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(17)42907-3

Noncomplementing mutations in a nuclear gene (CBP1) of Saccharomyces cerevisiae D273-10B specifically affect the synthesis of cytochrome b, a mitochondrially encoded carrier of the respiratory chain. The nuclear mutants have been shown to have lowered levels of cytochrome b-specific transcripts. This phenotype is attributed to the inability of the mutant strains to process the 5' end of the cytochrome b pre-mRNA. Impairment of the processing function encoded by the CBP1 gene introduces an instability in the transcripts and promotes nucleolytic degradation. Mutations in CBP1 can be suppressed by a p- genome in which the 5' untranslated leader of the oli1 gene (subunit 9 of the ATPase) is fused near the 5' side of the cytochrome b coding sequence. The rearranged genome allows the cytochrome b gene to be transcribed from the oli1 promoter and results in novel cytochrome b transcripts with the 5' leader sequence of the oli1 mRNA. The presence of the oli1 leader sequence confers stability to the RNA and circumvents the CBP1 processing function.