title: Regulation of the nuclear-coded peptides of yeast cytochrome c oxidase.
abstract: We have analyzed the catabolite regulation of cytochrome oxidase by assaying changes in the synthesis of precursors of the nuclear-coded peptides (IV--VII) of cytochrome c oxidase in an in vitro reticulocyte cell-free system programmed with RNA isolated from cells grown in either glucose or raffinose. As a first step, we have characterized antibodies which bind to the precursors of subunits V and VI. Initial translation products for subunits IV and VII have also been tentatively identified by utilizing these antibodies. The messenger RNAs coding for the precursors of the nuclear-coded subunits fall in the expected size range of 8--15 S. Catabolite repression of the nuclear-coded oxidase peptides appears to be regulated by the abundance of their messenger RNAs. Translation of messenger RNA isolated from yeast cells grown on glucose indicates a coordinate and uniform increase in precursor synthesis during glucose derepression. In contrast, when RNA isolated from raffinose (derepressed) grown cells is used to direct cell-free translation, precursor abundance is high throughout growth, although the synthesis of some of the species changes in a complex pattern of ratio and abundance. These data indicate that the abundance of the messengers for the nuclear-coded precursors is regulated in a fashion dependent on the physiologic state of the cell.
mesh_terms: D003576:Electron Transport Complex IV / Q000235:genetics*; D004792:Enzyme Precursors / Q000235:genetics; D004794:Enzyme Repression; D005786:Gene Expression Regulation; D005796:Genes; D007425:Intracellular Membranes / Q000201:enzymology; D046911:Macromolecular Substances; D008928:Mitochondria / Q000201:enzymology; D008970:Molecular Weight; D012333:RNA, Messenger / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D004792:Enzyme Precursors; D046911:Macromolecular Substances; D012333:RNA, Messenger; D003576:Electron Transport Complex IV