High impact information on COX1

• The defect in COX1 gene expression in the pet54 mutant was shown to be the result of inefficient excision of COX1 intron aI5 beta [1].
• First, a pet54::LEU2 cytoductant bearing the 'short' mitochondrial genome that lacks both COX1 introns aI5 alpha and aI5 beta is defective only in COX3 gene expression and not in COX1 mRNA splicing or mRNA translation [1].
• Genetic evidence that different functional domains of the PET54 gene product facilitate expression of the mitochondrial genes COX1 and COX3 in Saccharomyces cerevisiae [2].
• Two of these five mutants were defective in expression of COX3 but not in expression of COX1, while two other mutants had the opposite phenotype (primarily defective in expression of COX1) [2].
• This protein, encoded by the PET54 gene, controls expression of COX1 at the level of RNA splicing and COX3 at the level of mRNA translation [2].

Biological context of COX1

• Two lines of evidence indicate that inefficient excision of intron aI5 beta is the sole defect in COX1 gene expression [1].
• In most strains of Saccharomyces cerevisiae the mitochondrial gene COX1, for subunit 1 of cytochrome oxidase, contains multiple exons and introns [3].
• Here we show that the low molecular weight protein product of open reading frame YLR204W, for which we propose the name COX24, is also involved in processing of COX1 RNA intermediates [3].
• COX1 messenger RNA synthesis is initiated in a conserved nonanucleotide sequence (ATATAAGTA) which we have previously found immediately upstream of ribosomal RNA genes at positions at which RNA synthesis starts [4].
• We have investigated the expression of a continuous open reading frame (ORF) present in the mitochondrial genome of Acanthamoeba castellanii and specifying the two largest subunits (COX1 and COX2) of the cytochrome c oxidase complex [5].

Anatomical context of COX1

• The MSS51 gene product is required for the translation of the COX1 mRNA in yeast mitochondria [6].
• Here, we report that Pet100p does not affect the localization of cytochrome c oxidase subunit polypeptides to the inner mitochondrial membrane but instead functions after they have arrived at the inner membrane [7].

Associations of COX1 with chemical compounds

• To extend these observations, we examined the (R)- and (S)- enantiomers of RS- ketorolac, (S)- ketorolac exhibited potent COX1 and COX2 enzyme inhibition, whereas (R)- ketorolac was > 100-fold less active on both COX subtypes [8].

Other interactions of COX1

• Using mt genes from Saccharomyces cerevisiae, six structural genes (large rRNA, apocytochrome b, cytochrome c oxidase subunit I and subunit II, ATPase subunit 6 and subunit 9) were located on the C. maltosa chondriome by cross hybridization experiments [9].

Analytical, diagnostic and therapeutic context of COX1

• A yeast two-hybrid assay showed the BK-beta1 protein can interact with a mitochondrial protein, cytochrome c oxidase subunit I (Cco1) [10].

References