Bradyrhizobium japonicum senses iron through the status of haem to regulate iron homeostasis and metabolism

The Irr protein from the bacterium Bradyrhizobium japonicum is expressed under iron limitation to mediate iron control of haem biosynthesis. The regulatory input to Irr is the status of haem and its precursors iron and protoporphyrin at the site of haem synthesis. Here, we show that Irr controls the...

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Main Authors:	Yang, Jianhua, Sangwan, Indu, Lindemann, Andrea, Hauser, Felix, Hennecke, Hauke, Fischer, Hans-Martin, O'Brian, Mark R
Format:	Online
Language:	English
Published:	Blackwell Publishing Ltd 2006
Online Access:	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1424673/

id	pubmed-1424673
recordtype	oai_dc
spelling	pubmed-14246732006-10-02 Bradyrhizobium japonicum senses iron through the status of haem to regulate iron homeostasis and metabolism Yang, Jianhua Sangwan, Indu Lindemann, Andrea Hauser, Felix Hennecke, Hauke Fischer, Hans-Martin O'Brian, Mark R Research Articles The Irr protein from the bacterium Bradyrhizobium japonicum is expressed under iron limitation to mediate iron control of haem biosynthesis. The regulatory input to Irr is the status of haem and its precursors iron and protoporphyrin at the site of haem synthesis. Here, we show that Irr controls the expression of iron transport genes and many other iron-regulated genes not directly involved in haem synthesis. Irr is both a positive and negative effector of gene expression, and in at least some cases the control is direct. Loss of normal iron responsiveness of those genes in an irr mutant, as well as a lower total cellular iron content, suggests that Irr is required for the correct perception of the cellular iron status. Degradation of Irr in iron replete cells requires haem. Accordingly, control of Irr-regulated genes by iron was aberrant in a haem-defective strain, and iron replete mutant cells behave as if they are iron-limited. In addition, the haem mutant had an abnormally high cellular iron content. The findings indicate that B. japonicum senses iron via the status of haem biosynthesis in an Irr-dependent manner to regulate iron homeostasis and metabolism. Blackwell Publishing Ltd 2006-04 2006-03-03 /pmc/articles/PMC1424673/ /pubmed/16573691 http://dx.doi.org/10.1111/j.1365-2958.2006.05101.x Text en ©2006 The Authors Journal compilation ©2006 Blackwell Publishing Ltd
repository_type	Open Access Journal
institution_category	Foreign Institution
institution	US National Center for Biotechnology Information
building	NCBI PubMed
collection	Online Access
language	English
format	Online
author	Yang, Jianhua Sangwan, Indu Lindemann, Andrea Hauser, Felix Hennecke, Hauke Fischer, Hans-Martin O'Brian, Mark R
spellingShingle	Yang, Jianhua Sangwan, Indu Lindemann, Andrea Hauser, Felix Hennecke, Hauke Fischer, Hans-Martin O'Brian, Mark R Bradyrhizobium japonicum senses iron through the status of haem to regulate iron homeostasis and metabolism
author_facet	Yang, Jianhua Sangwan, Indu Lindemann, Andrea Hauser, Felix Hennecke, Hauke Fischer, Hans-Martin O'Brian, Mark R
author_sort	Yang, Jianhua
title	Bradyrhizobium japonicum senses iron through the status of haem to regulate iron homeostasis and metabolism
title_short	Bradyrhizobium japonicum senses iron through the status of haem to regulate iron homeostasis and metabolism
title_full	Bradyrhizobium japonicum senses iron through the status of haem to regulate iron homeostasis and metabolism
title_fullStr	Bradyrhizobium japonicum senses iron through the status of haem to regulate iron homeostasis and metabolism
title_full_unstemmed	Bradyrhizobium japonicum senses iron through the status of haem to regulate iron homeostasis and metabolism
title_sort	bradyrhizobium japonicum senses iron through the status of haem to regulate iron homeostasis and metabolism
description	The Irr protein from the bacterium Bradyrhizobium japonicum is expressed under iron limitation to mediate iron control of haem biosynthesis. The regulatory input to Irr is the status of haem and its precursors iron and protoporphyrin at the site of haem synthesis. Here, we show that Irr controls the expression of iron transport genes and many other iron-regulated genes not directly involved in haem synthesis. Irr is both a positive and negative effector of gene expression, and in at least some cases the control is direct. Loss of normal iron responsiveness of those genes in an irr mutant, as well as a lower total cellular iron content, suggests that Irr is required for the correct perception of the cellular iron status. Degradation of Irr in iron replete cells requires haem. Accordingly, control of Irr-regulated genes by iron was aberrant in a haem-defective strain, and iron replete mutant cells behave as if they are iron-limited. In addition, the haem mutant had an abnormally high cellular iron content. The findings indicate that B. japonicum senses iron via the status of haem biosynthesis in an Irr-dependent manner to regulate iron homeostasis and metabolism.
publisher	Blackwell Publishing Ltd
publishDate	2006
url	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1424673/
_version_	1611381648390094848

Bradyrhizobium japonicum senses iron through the status of haem to regulate iron homeostasis and metabolism

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