Record Details

An Intrinsic Alkalization Circuit Turns on mntP Riboswitch under Manganese Stress in Escherichia coli

DIR@IMTECH: CSIR-Institute of Microbial Technology

View Archive Info
 
 
Field Value
 
Title An Intrinsic Alkalization Circuit Turns on mntP Riboswitch under Manganese Stress in Escherichia coli
 
Creator Kalita, Arunima
Mishra, Rajesh Kumar
Kumar, Vineet
Arora, Amit
Dutta, Dipak
 
Subject QR Microbiology
 
Description The trace metal manganese in excess affects iron-sulfur cluster and heme-protein biogenesis, eliciting cellular toxicity. The manganese efflux protein MntP is crucial to evading manganese toxicity in bacteria. Recently, two Mn-sensing riboswitches upstream of mntP and alx in Escherichia coli have been reported to mediate the upregulation of their expression under manganese shock. As the alx riboswitch is also responsive to alkaline shock administered externally, it is intriguing whether the mntP riboswitch is also responsive to alkaline stress. Furthermore, how both manganese and alkaline pH simultaneously regulate these two riboswitches under physiological conditions is a puzzle. Using multiple approaches, we show that manganese shock activated glutamine synthetase (GlnA) and glutaminases (GlsA and GlsB) to spike ammonia production in E. coli. The elevated ammonia intrinsically alkalizes the cytoplasm. We establish that this alkalization under manganese stress is crucial for attaining the highest degree of riboswitch activation. Additional studies showed that alkaline pH promotes a 17- to 22-fold tighter interaction between manganese and the mntP riboswitch element. Our study uncovers a physiological linkage between manganese efflux and pH homeostasis that mediates enhanced manganese tolerance. IMPORTANCE Riboswitch RNAs are cis-acting elements that can adopt alternative conformations in the presence or absence of a specific ligand(s) to modulate transcription termination or translation initiation processes. In the present work, we show that manganese and alkaline pH are both necessary for maximal mntP riboswitch activation to mitigate the manganese toxicity. This study bridges the gap between earlier studies that separately emphasize the importance of alkaline pH and manganese in activating the riboswitches belonging to the yybP-ykoY family. This study also ascribes a physiological relevance as to how manganese can rewire cellular physiology to render cytoplasmic pH alkaline for its homeostasis.
 
Publisher American Chemical Society
 
Date 2022-10-26
 
Type Article
PeerReviewed
 
Relation https://journals.asm.org/doi/full/10.1128/spectrum.03368-22?rfr_dat=cr_pub++0pubmed&url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org
http://crdd.osdd.net/open/3037/
 
Identifier Kalita, Arunima and Mishra, Rajesh Kumar and Kumar, Vineet and Arora, Amit and Dutta, Dipak (2022) An Intrinsic Alkalization Circuit Turns on mntP Riboswitch under Manganese Stress in Escherichia coli. MICROBIOLOGY SPECTRUM, 10 (5).