title: Copper supplementation increases yeast life span under conditions requiring respiratory metabolism.
abstract: To further exploit yeast as a model for cellular aging we have modified the replicative life span assay to force respiration, by replacing glucose with the non-fermentable carbon source glycerol. The growth rates of several different strains varied greatly, with doubling times ranging from 2.7 to 7 h. Life spans of all strains were lower on media containing glycerol than on media containing glucose. However, supplementation of glycerol-containing media with copper resulted in increases in life span of between 17 and 72%; life spans equivalent to or beyond those obtained on glucose media. Addition of copper to glucose medium had no effect on life span. Microarray analysis showed that genes responsible for high affinity import of copper display reduced expression upon addition of copper, while most genes showed no change in expression. No differences in growth rate, oxygen uptake, or the levels of subunit II of the copper-containing cytochrome c oxidase were found between cultures of yeast grown with or without copper supplementation. Copper supplementation greatly extended the life span of sod1 and sod2 strains, suggesting that addition of copper may reduce the generation of superoxide. Forcing yeast to respire places an emphasis on mitochondrial function and may aid in the identification of factors involved in aging in other respiratory-dependent organisms.
authors.affiliation: Harriet L. Wilkes Honors College, Florida Atlantic University, 5353 Parkside Dr., Jupiter, FL 33458, United States. pkirchma@fau.edu
authors.forename: Paul A
authors.initials: PA
authors.lastname: Kirchman
authors.forename: Gabriela
authors.initials: G
authors.lastname: Botta
mesh_terms: D017920:Antiporters / Q000235:genetics / Q000378:metabolism; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism; D049109:Cell Proliferation; D003300:Copper / Q000494:pharmacology*; D000079923:Copper Transporter 1; D003470:Culture Media / Q000494:pharmacology; D003576:Electron Transport Complex IV / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D005947:Glucose / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism*; D009154:Mutation; D010100:Oxygen / Q000378:metabolism; D011401:Promoter Regions, Genetic; D000080083:SLC31 Proteins; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000187:drug effects* / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism
chemical_list: D017920:Antiporters; C490078:CTR1 protein, S cerevisiae; C100982:CTR3 protein, S cerevisiae; D027682:Cation Transport Proteins; D000079923:Copper Transporter 1; D003470:Culture Media; D000080083:SLC31 Proteins; D029701:Saccharomyces cerevisiae Proteins; D003300:Copper; D013482:Superoxide Dismutase; D003576:Electron Transport Complex IV; D005947:Glucose; D005990:Glycerol; D010100:Oxygen