Potassium and the K+/H+ exchanger Kha1p promote binding of copper to ApoFet3p multi-copper ferroxidase

Xiaobin Wu, Heejeong Kim, Javier Seravalli, Joseph J. Barycki, P. John Hart, David W. Gohara, Enrico Di Cera, Won Hee Jung, Daniel J. Kosman, Jaekwon Lee

Research output: Contribution to journalArticlepeer-review

18 Scopus citations


Acquisition and distribution of metal ions support a number of biological processes. Here we show that respiratory growth of and iron acquisition by the yeast Saccharomyces cerevisiae relies on potassium (K+) compartmentalization to the trans-Golgi network via Kha1p, a K+/H+ exchanger. K+ in the trans-Golgi network facilitates binding of copper to the Fet3p multi-copper ferroxidase. The effect of K+ is not dependent on stable binding with Fet3p or alteration of the characteristics of the secretory pathway. The data suggest that K+ acts as a chemical factor in Fet3p maturation, a role similar to that of cations in folding of nucleic acids. Up-regulation of KHA1 gene in response to iron limitation via iron-specific transcription factors indicates that K+ compartmentalization is linked to cellular iron homeostasis. Our study reveals a novel functional role of K+ in the binding of copper to apoFet3p and identifies a K+/H+ exchanger at the secretory pathway as a new molecular factor associated with iron uptake in yeast.

Original languageEnglish (US)
Pages (from-to)9796-9806
Number of pages11
JournalJournal of Biological Chemistry
Issue number18
StatePublished - 2016

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology


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