Format

Send to

Choose Destination
J Biol Chem. 2016 Apr 29;291(18):9796-806. doi: 10.1074/jbc.M115.700500. Epub 2016 Mar 10.

Potassium and the K+/H+ Exchanger Kha1p Promote Binding of Copper to ApoFet3p Multi-copper Ferroxidase.

Author information

1
From the Department of Biochemistry and Redox Biology Center, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0664, College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, China 200234.
2
From the Department of Biochemistry and Redox Biology Center, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0664.
3
Department of Biochemistry, University of Texas Health Science Center, San Antonio, Texas 78229-3900.
4
Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri 63104.
5
Department of Systems Biotechnology, Chung-Ang University, Anseong, Korea 456-756, and.
6
Department of Biochemistry, University at Buffalo, Buffalo, New York 14214-3000.
7
From the Department of Biochemistry and Redox Biology Center, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0664, jlee7@unl.edu.

Abstract

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.

KEYWORDS:

copper; ferroxidase; iron; iron response element (IRE); potassium transport; protein secretion

PMID:
26966178
PMCID:
PMC4850315
DOI:
10.1074/jbc.M115.700500
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center