Disease relevance of cox1

• The open reading frame of the first intron of the mitochondrial cox1 gene (cox1I1) was expressed in Escherichia coli [1].

High impact information on cox1

• The mitochondrial genome of the fission yeast Schizosaccharomyces pombe: highly homologous introns are inserted at the same position of the otherwise less conserved cox1 genes in Schizosaccharomyces pombe and Aspergillus nidulans [2].
• The second intron in the cox1 gene of S. pombe contains an open reading frame, which is contiguous with the upstream exon and displays all characteristics common to class I introns [2].
• The DNA sequence of the second intron in the mitochondrial gene for subunit 1 of cytochrome oxidase (cox1), and the 3' part of the structural gene have been determined in Schizosaccharomyces pombe [2].
• Comparing the presumptive amino acid sequence of the 3' regions of the cox1 genes in fungi reveals similarly large evolutionary distances between Aspergillus nidulans, Saccharomyces cerevisiae and S. pombe [2].
• Cox11 is an intrinsic mitochondrial membrane protein essential for the assembly of an active cytochrome c oxidase complex [3].

Biological context of cox1

• As was seen for the Sch. pombe cox1 gene (Lang, 1984), the cob exons are translated using the universal genetic code and this distinguishes Sch. pombe mitochondria from all other fungal and animal mitochondrial systems [4].
• The biogenesis of cytochrome c oxidase requires coordination between the nucleus and mitochondria because both these compartments provide the structural subunits of this enzyme [5].

Anatomical context of cox1

• The symporter protein was reconstituted together with cytochrome-c oxidase prepared from beef heart mitochondria into proteo-liposomes [6].
• For this purpose plasma membranes of Schizosaccharomyces pombe cells transformed with the HUP1 gene coding for the H+/hexose symporter of Chlorella kessleri were fused with cytochrome-c oxidase containing proteoliposomes [7].
• Gentle disruption of such spheroplasts yielded homogenates, from which marker enzymes for nuclei (NAD pyrophosphorylase) and mitochondria (cytochrome c oxidase activity and spectroscopically-detectable cytochromes a + a3) could be quantitatively sedimented by low-speed centrifugation [8].

Associations of cox1 with chemical compounds

• Cytochrome-c oxidase is a redox-driven H(+)-pump generating a proton motive force (inside negative and alkaline) while transferring electrons from cytochrome-c to oxygen; this energy is used by the symporter to accumulate D-glucose at least 30-fold [6].
• In contrast to previous findings with Saccharomyces carlsbergensis, cytochrome c oxidase and another mitochondrial enzyme, succinate dehydrogenase, were completely sedimentable by zonal centrifugation in sucrose gradients in the presence of either 2 mM-MgCl2 or 0-4 mM-EDTA [8].

References