Affiliation:
1. Okinawa Institute of Science and Technology Graduate University, Tancha 1919-1, Onna, Okinawa 904-0495, Japan
2. Institute of Life Science, Kurume University, Asahi-machi 67, Kurume, Fukuoka 830-0011, Japan
Abstract
Mitochondria perform critical functions, including respiration, ATP production, small molecule metabolism, and anti-oxidation, and they are involved in a number of human diseases. While the mitochondrial genome contains a small number of protein-coding genes, the vast majority of mitochondrial proteins are encoded by nuclear genes. In fission yeast
Schizosaccharomyces pombe
, we screened 457 deletion (
del
) mutants deficient in nuclear-encoded mitochondrial proteins, searching for those that fail to form colonies in culture medium containing low glucose (0.03–0.1%; low-glucose sensitive,
lgs
), but that proliferate in regular 2–3% glucose medium. Sixty-five (14%) of the 457 deletion mutants displayed the
lgs
phenotype. Thirty-three of them are defective either in dehydrogenases, subunits of respiratory complexes, the citric acid cycle, or in one of the nine steps of the CoQ10 biosynthetic pathway. The remaining 32
lgs
mutants do not seem to be directly related to respiration. Fifteen are implicated in translation, and six encode transporters. The remaining 11 function in anti-oxidation, amino acid synthesis, repair of DNA damage, microtubule cytoskeleton, intracellular mitochondrial distribution or unknown functions. These 32 diverse
lgs
genes collectively maintain mitochondrial functions under low (1/20–1/60× normal) glucose concentrations. Interestingly, 30 of them have homologues associated with human diseases.
Funder
Okinawa Institute of Science and Technology Graduate University
Japan Society for the Promotion of Science