High impact information on CTR3

• In such strains inactivation of both CTR1 and CTR3 is required to generate lethal copper-deficient phenotypes [1].
• Upon addition of CuSO4, mRNA levels of CTR3 were rapidly reduced to eightfold the original basal level whereas the Ace1p-mediated transcriptional activation of CUP1 was rapid and potent but transient [2].
• Although Ctr1 and Ctr3 are functionally redundant, they bear little homology at the amino acid sequence level [3].
• Unlike Ctr1, the Ctr3 transporter is neither regulated at the level of protein degradation nor endocytosis as a function of elevated copper levels [3].
• Ctr3 is an integral membrane protein that assembles as a trimer to form a competent copper uptake permease at the plasma membrane [3].

Biological context of CTR3

• Furthermore, copper-starvation rapidly and potently induces CTR3 gene expression [4].

Associations of CTR3 with chemical compounds

• Although copper represses CTR3 gene expression at picomolar metal concentrations, cadmium and mercury down-regulate CTR3 expression only at concentrations 3 orders magnitude greater [4].
• Ctr3p is a small intracellular cysteine-rich integral membrane protein that restores high-affinity Cu uptake, Cu, Zn superoxide dismutase activity, ferrous iron transport, and respiratory proficiency to strains lacking the CTR1 (Cu transporter 1) gene [1].

Other interactions of CTR3

• Under copper-limiting conditions, yeast cells harbouring deletions of the MAC1, CTR1 and CTR3 genes were defective in amine oxidase activity [5].
• These include the FRE1-encoded Cu2+/Fe3+ reductase and the CTR1 and CTR3-encoded membrane-associated copper transport proteins [4].
• Inaddition to Ctrlp, Ctr2p, Ctr3p and Fet4p, other metal transport systems can act as upstream donors of copper for the metallochaperones when copper availability in the medium is increased [6].

References