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Title: The iron uptake repressor Fep1 in the fission yeast binds Fe-S cluster through conserved cysteines

Abstract

Iron homeostasis is tightly regulated since iron is an essential but toxic element in the cell. The GATA-type transcription factor Fep1 and its orthologs contribute to iron homeostasis in many fungi by repressing genes for iron uptake when intracellular iron is high. Even though the function and interaction partners of Fep1 have been elucidated extensively In Schizosaccharomyces pombe, the mechanism behind iron-sensing by Fep1 remains elusive. It has been reported that Fep1 interacts with Fe-S-containing monothiol glutaredoxin Grx4 and Grx4-Fra2 complex. In this study, we demonstrate that Fep1 also binds iron, in the form of Fe-S cluster. Spectroscopic and biochemical analyses of as isolated and reconstituted Fep1 suggest that the dimeric Fep1 binds Fe-S clusters. The mutation study revealed that the cluster-binding depended on the conserved cysteines located between the two zinc fingers in the DNA binding domain. EPR analyses revealed [Fe-S]-specific peaks indicative of mixed presence of [2Fe-2S], [3Fe-4S], or [4Fe-4S]. The finding that Fep1 is an Fe-S protein fits nicely with the model that the Fe-S-trafficking Grx4 senses intracellular iron environment and modulates the activity of Fep1. - Highlights: • Fep1, a prototype fungal iron uptake regulator, was isolated stably from Schizosaccharomyces pombe. • Fep1 exhibits UV–visible absorptionmore » spectrum, characteristic of [Fe-S] proteins. • The iron and sulfide contents in purified or reconstituted Fep1 also support [Fe-S]. • The conserved cysteines are critical for [Fe-S]-binding. • EPR spectra at 5 K and 123 K suggest a mixed population of [Fe-S].« less

Authors:
; ; ;
Publication Date:
OSTI Identifier:
22606209
Resource Type:
Journal Article
Resource Relation:
Journal Name: Biochemical and Biophysical Research Communications; Journal Volume: 478; Journal Issue: 1; Other Information: Copyright (c) 2016 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; ABSORPTION; ABSORPTION SPECTRA; CYSTEINE; DNA; ELECTRON SPIN RESONANCE; HOMEOSTASIS; IRON; MUTATIONS; SULFIDES; TOXICITY; TRANSCRIPTION; TRANSCRIPTION FACTORS; UPTAKE; YEASTS

Citation Formats

Kim, Hyo-Jin, Lee, Kang-Lok, Kim, Kyoung-Dong, and Roe, Jung-Hye, E-mail: jhroe@snu.ac.kr. The iron uptake repressor Fep1 in the fission yeast binds Fe-S cluster through conserved cysteines. United States: N. p., 2016. Web. doi:10.1016/J.BBRC.2016.07.070.
Kim, Hyo-Jin, Lee, Kang-Lok, Kim, Kyoung-Dong, & Roe, Jung-Hye, E-mail: jhroe@snu.ac.kr. The iron uptake repressor Fep1 in the fission yeast binds Fe-S cluster through conserved cysteines. United States. doi:10.1016/J.BBRC.2016.07.070.
Kim, Hyo-Jin, Lee, Kang-Lok, Kim, Kyoung-Dong, and Roe, Jung-Hye, E-mail: jhroe@snu.ac.kr. Fri . "The iron uptake repressor Fep1 in the fission yeast binds Fe-S cluster through conserved cysteines". United States. doi:10.1016/J.BBRC.2016.07.070.
@article{osti_22606209,
title = {The iron uptake repressor Fep1 in the fission yeast binds Fe-S cluster through conserved cysteines},
author = {Kim, Hyo-Jin and Lee, Kang-Lok and Kim, Kyoung-Dong and Roe, Jung-Hye, E-mail: jhroe@snu.ac.kr},
abstractNote = {Iron homeostasis is tightly regulated since iron is an essential but toxic element in the cell. The GATA-type transcription factor Fep1 and its orthologs contribute to iron homeostasis in many fungi by repressing genes for iron uptake when intracellular iron is high. Even though the function and interaction partners of Fep1 have been elucidated extensively In Schizosaccharomyces pombe, the mechanism behind iron-sensing by Fep1 remains elusive. It has been reported that Fep1 interacts with Fe-S-containing monothiol glutaredoxin Grx4 and Grx4-Fra2 complex. In this study, we demonstrate that Fep1 also binds iron, in the form of Fe-S cluster. Spectroscopic and biochemical analyses of as isolated and reconstituted Fep1 suggest that the dimeric Fep1 binds Fe-S clusters. The mutation study revealed that the cluster-binding depended on the conserved cysteines located between the two zinc fingers in the DNA binding domain. EPR analyses revealed [Fe-S]-specific peaks indicative of mixed presence of [2Fe-2S], [3Fe-4S], or [4Fe-4S]. The finding that Fep1 is an Fe-S protein fits nicely with the model that the Fe-S-trafficking Grx4 senses intracellular iron environment and modulates the activity of Fep1. - Highlights: • Fep1, a prototype fungal iron uptake regulator, was isolated stably from Schizosaccharomyces pombe. • Fep1 exhibits UV–visible absorption spectrum, characteristic of [Fe-S] proteins. • The iron and sulfide contents in purified or reconstituted Fep1 also support [Fe-S]. • The conserved cysteines are critical for [Fe-S]-binding. • EPR spectra at 5 K and 123 K suggest a mixed population of [Fe-S].},
doi = {10.1016/J.BBRC.2016.07.070},
journal = {Biochemical and Biophysical Research Communications},
number = 1,
volume = 478,
place = {United States},
year = {Fri Sep 09 00:00:00 EDT 2016},
month = {Fri Sep 09 00:00:00 EDT 2016}
}