High impact information on CCS1

• We show that loss of the Cu,Zn-dependent superoxide dismutase, SOD1, or its copper chaperone, LYS7, confers oxygen-dependent sensitivity to replication arrest and DNA damage in Saccharomyces cerevisiae [1].
• Loss of SOD1 and LYS7 sensitizes Saccharomyces cerevisiae to hydroxyurea and DNA damage agents and downregulates MEC1 pathway effectors [1].
• Thus, the copper ions are properly directed to their native binding sites in vivo, presumably as a result of the action of the yeast copper chaperone Lys7p (yeast CCS) [2].
• We have cloned, mapped and sequenced the wild-type and mutant alleles of MCM1, which is located on the right arm of chromosome XIII near LYS7 [3].
• PDR4 was mapped to chromosome XIII, 31.5 cM from LYS7 and 9 cM from the centromere [4].

Biological context of CCS1

• In this communication we provide evidence that Lys7p is involved in oxidative stress protection [5].
• I have used strains harboring the far3-1 mutation to map the gene to the right arm of chromosome XIII, establishing the gene order CEN13-LYS7-MCM1-FAR3 [6].
• Two yet uncharacterized fungal genes, q10474 of Schizosaccharomyces pombe, meanwhile annotated as the putative lys7 gene, and npgA of Aspergillus nidulans, also complemented the lys5 deletion and have thus been functionally characterized as PPTases [7].
• The lys7 delta mutant requires lysine and simultaneously displays an array of phenotypes that include pH and temperature sensitivity [8].
• The Sz. pombe Lys1p amino acid sequence showed a high degree of similarity to other fungal Lys2p proteins; however, the Lys7p amino acid sequence showed much less similarity to other bacterial, fungal and animal PPTases representing several phylogenetic groups [9].

Associations of CCS1 with chemical compounds

• Saccharomyces cerevisiae Lys7p was proposed to be the enzyme catalyzing the dehydratation of homocitrate to cis-homoaconitate, the second step of the lysine biosynthetic pathway [5].
• Cells deleted for the LYS7 gene displayed, in addition to lysine auxotrophy, methionine auxotrophy, sensitivity to superoxide generating drugs and light irradiation, and diminution of calcineurin activity [5].
• Somewhat higher AAR activity was obtained with the addition of CoA and the Sz. pombe Lys7p PPTase [9].
• In the linear analogs, replacement of both Lys7 and Gln10 with a cysteine residue resulted in an over 100-fold loss of the biological activity when compared with the native pheromone [10].
• Analogs of the Saccharomyces cerevisiae alpha-mating factor, Trp-His-Trp-Leu-Gln-Leu-Lys-Pro-Gly-Gln-Pro-Met-Tyr, where Lys7 and Gln10 were replaced with Cys, Cys(CH3), or Ser, were synthesized using solid-phase procedures on a phenylacetamidomethyl resin [10].

Other interactions of CCS1

• Dual SOD1 + CCS1 overexpression elevated the levels of Cu,Zn-Sod activity six- to eight-fold in vegetative cultures [11].
• Mutants in the corresponding gene (lys7) are defective for SOD1 activity, and are unable to incorporate copper into SOD1, while there is no obvious impairment in copper delivery to cytochrome oxidase of Fet3p [12].
• A DNA fragment complementing the 10.25 mutation has been cloned; sequence analysis of the cloned gene (named lys7) revealed that it encoded a protein with high similarity to the saccharopine reductase from Neurospora crassa, Magnaporthe grisea, Saccharomyces cerevisiae, and Schizosaccharomyces pombe [13].
• Posttranslational activation, site-directed mutation and phylogenetic analyses of the lysine biosynthesis enzymes alpha-aminoadipate reductase Lys1p (AAR) and the phosphopantetheinyl transferase Lys7p (PPTase) from Schizosaccharomyces pombe [9].

Analytical, diagnostic and therapeutic context of CCS1

• X-ray crystallographic and analytical ultracentrifugation analyses of truncated and full-length yeast copper chaperones for SOD (LYS7): a dimer-dimer model of LYS7-SOD association and copper delivery [14].
• The data presented here, however, taken together with previously published crystallographic and analytical gel filtration data on full-length LYS7, suggest an alternative model wherein a dimer of LYS7 interacts with a dimer of yeast CuZnSOD [14].
• A Northern blot experiment demonstrated that LYS7 transcription was not regulated by lysine-specific or general aa control mechanisms [8].

References