Promotion of Zn(2+) uptake by Al (3+) in a Saccharomyces Cerevisiae mutant that lacks the ZRT1 gene encoding a high-affinity Zn transporter.
A Saccharomyces cerevisiae mutant (zrt1Delta) lacking the ZRT1 gene, which encodes a high-affinity Zn(2+) transporter, scarcely thrived in a low-pH, low-phosphate medium because of Zn(2+) deficiency. Supplementation of the medium with Al(3+) restored growth to a level comparable to that of a wild-type strain. A metal determination study clearly demonstrated that Al(3+) induced the incorporation of Zn(2+) into zrt1Delta cells, probably through the low-affinity Zn(2+) transporter Zrt2p, given that the zrt1Deltazrt2Delta double mutant did not show Al-induced growth enhancement. Al(3+) may have altered the speciation of Zn(2+) in the medium, resulting in enhanced levels of free Zn(2+). Alternatively, it might be that Zrt2p was degraded by endocytosis in the absence of Al(3+) and Al(3+) interfered with this process, resulting in enhanced Zn(2+) accumulation.
Tamura
Shun
S
Department of Applied Biological Chemistry, School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, 113-8657, Japan.
Yoshimura
Etsuro
E
D000535:Aluminum / Q000494:pharmacology*; D001692:Biological Transport / Q000187:drug effects; D027682:Cation Transport Proteins / Q000235:genetics / Q000502:physiology*; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D009154:Mutation; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000502:physiology*; D015032:Zinc / Q000378:metabolism* / Q000493:pharmacokinetics
D027682:Cation Transport Proteins; D029701:Saccharomyces cerevisiae Proteins; C098750:ZRT1 protein, S cerevisiae; D000535:Aluminum; D015032:Zinc