Coq3-KO Mouse

Coq3, encoding 3,4-dihydroxy-5-polyprenylbenzoate methyltransferase, is crucial for coenzyme Q (Q) biosynthesis [2,3,5,7]. Q is a redox-active lipid essential for aerobic respiration in eukaryotes, with Coq3 catalyzing two O-methylation steps in the Q biosynthetic pathway [3,4,6].

In yeast, Coq3 and Coq4 form a high-molecular-mass complex for Q biosynthesis [1]. Coq3, along with other Coq polypeptides like Coq1, Coq5, and Coq6, is part of a larger complex involved in Q production [1]. The Arabidopsis homologue AtCOQ3 also functions in mitochondrial ubiquinone synthesis [7]. Escherichia coli UbiG, an orthologue of Coq3, can complement yeast coq3 mutants and catalyze both O-methylation steps [4]. The activity and expression of Coq3 O-methyltransferase depend on other COQ gene products, suggesting a multi-subunit complex in Q biosynthesis [8].

In conclusion, Coq3 is essential for coenzyme Q biosynthesis, a process conserved across species from yeast to plants and mammals. Understanding Coq3 function through model-based research, such as in yeast mutants, helps in revealing its role in maintaining aerobic respiration and may have implications for understanding diseases related to Q deficiencies, like the symptoms seen in mouse mutants similar to human Q-deficiency conditions [2].