Disease relevance of COQ7

• We have cloned COQ7 from Pseudomonas aeruginosa and Thiobacillus ferrooxidans and show that indeed this gene complements an Escherichia coli mutant that lacks an unrelated 5-demethoxyubiquinone hydroxylase [1].

High impact information on COQ7

• Coq7p, the Saccharomyces cerevisiae homologue, is essential for ubiquinone (coenzyme Q or Q) synthesis and therefore respiration [2].
• In yeast, mutation of the COQ7 gene results in the absence of UQ biosynthesis and demonstrates a role for this gene in the step leading to the hydroxylation of 5-demethoxyubiquinone [1].
• Here we identify Coq7 as belonging to a family of a di-iron containing oxidases/hydroxylases based on a conserved sequence motif for the iron ligands, supporting a direct function of Coq7 as a hydroxylase [1].
• The Saccharomyces cerevisiae homologue COQ7/CAT5 is essential for several metabolic pathways including ubiquinone biosynthesis, respiration, and gluconeogenic gene activation [3].
• Further investigations are necessary to elucidate the exact role of CS-1 and ubiquinone biosynthesis protein COQ7 in the setting of hypertension-induced LVH [4].

Biological context of COQ7

• Zoo blot analysis implied that the COQ7 gene was well conserved among mammal, bird, and reptile genomes [5].
• Genomic analyses revealed that the human COQ7 gene is composed of six exons spanning 11 kb of human genome as a single-copy gene [5].
• The number and location of human CLK1 introns were determined, and the location of introns II and IV are the same as in C. elegans [6].

Anatomical context of COQ7

• Tissue blot analysis showed that human COQ7 is dominantly transcribed in heart and skeletal muscle [5].
• Biochemical analysis revealed that COQ7 is targeted to mitochondria where it is processed to mature form [7].
• In the light, when glyoxysomes were transformed to leaf-type peroxisomes, the five more-basic forms (CAT 1 through CAT 5) became more prominent, while amounts of the three more-acidic forms (CAT 6 through CAT 8) decreased considerably [8].

Associations of COQ7 with chemical compounds

• Here CLK-1 is shown to be related to the ubiquinol oxidase, alternative oxidase, and belong to the functionally diverse di-iron-carboxylate protein family which includes bacterioferritin and methane mono-oxygenase [9].
• Fenofibrate increases the expression and activity of hepatic enzymes and cofactors involved in lipid handling and UCP3 activity and, as is the case for UCP3, induces other muscle-specific genes (e.g., Carnitine palmitoyl transferase 1b and Ubiquinone biosynthesis protein COQ7 homolog) [10].

Analytical, diagnostic and therapeutic context of COQ7

• Northern blot analysis showed that three different isoforms of CLK-1 mRNA are present in several tissues and that the isoforms differ in the amount of expression [6].
• Human CLK-1 was mapped to Chr 16(p12-13.1) by Radiation Hybrid (RH) and fluorescence in situ hybridization (FISH) methods [6].

References