Uptake of lead and iron by divalent metal transporter 1 in yeast and mammalian cells.
Although the divalent metal transporter (DMT1) was suggested to transport a wide range of metals in Xenopus oocytes, recent studies in other models have provided contrasting results. Here, we provide direct evidence demonstrating that DMT1 expressed in yeast mutants defective for high affinity iron transport facilitates the transport of iron with an 'apparent K(m)' of approximately 1.2 microM, and transport of lead with an 'apparent K(m)' of approximately 1.8 microM. DMT1-dependent lead transport was H(+)-dependent and was inhibited by iron. Human embryonic kidney fibroblasts (HEK293 cells) overexpressing DMT1 also showed a higher uptake of lead than HEK293 cells without overexpressing DMT1. These results show that DMT1 transports lead and iron with similar affinity in a yeast model suggesting that DMT1 is a transporter for lead.
I  Bannon
Desmond
D
Kennedy Krieger Research Institute, 21205, Baltimore, MD, USA
Portnoy
Matthew E
ME
Olivi
Luisa
L
Lees
Peter S J
PS
Culotta
Valeria C
VC
Bressler
Joseph P
JP
D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D027682:Cation Transport Proteins; D002460:Cell Line; D018076:DNA, Complementary / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D006859:Hydrogen / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000378:metabolism / Q000493:pharmacokinetics*; D033862:Iron-Binding Proteins; D007700:Kinetics; D007854:Lead / Q000378:metabolism / Q000493:pharmacokinetics*; D009154:Mutation; D010957:Plasmids / Q000378:metabolism; D051381:Rats; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D013997:Time Factors; D000099236:Solute Carrier Family 11, Member 2
D002352:Carrier Proteins; D027682:Cation Transport Proteins; D018076:DNA, Complementary; D006859:Hydrogen; D007501:Iron; D033862:Iron-Binding Proteins; D007854:Lead; D000099236:Solute Carrier Family 11, Member 2