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Acetyl‐CoA synthetases of Saccharopolyspora erythraea are regulated by the nitrogen response regulator GlnR at both transcriptional and post‐translational levels
Author(s) -
You Di,
Wang MiaoMiao,
Ye BangCe
Publication year - 2017
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.13595
Subject(s) - biology , regulator , transcriptional regulation , microbiology and biotechnology , response regulator , computational biology , genetics , bacterial protein , transcription factor , gene
Summary Saccharopolyspora erythraea has three AMP‐forming acetyl‐CoA synthetases (Acs) encoded by acsA1 , acsA2 , and acsA3 . In this work, we found that nitrogen response regulator GlnR can directly interact with the promoter regions of all three genes and can activate their transcription in response to nitrogen availability. The typical GlnR‐binding boxes were identified in the promoter regions. Moreover, the activities of three Acs enzymes were modulated by the reversible lysine acetylation (RLA) with acetyltransferase AcuA and NAD + ‐dependent deacetylase SrtN. Interestingly, GlnR controlled the RLA by directly activating the expression of acuA and srtN . A glnR ‐deleted mutant (Δ glnR ) caused a growth defect in 10 mM acetate minimal medium, a condition under which RLA function is critical to control Acs activity. Overexpression of acuA reversed the growth defect of Δ glnR mutant. Total activity of Acs in cell‐free extracts from Δ glnR strain had a 4‐fold increase relative to that of wildtype strain. Western Blotting showed that in vivo acetylation levels of Acs were influenced by nitrogen availability and lack of glnR . These results demonstrated that GlnR regulated acetyl‐CoA synthetases at transcriptional and post‐translational levels, and mediated the interplay between nitrogen and carbon metabolisms by integrating nitrogen signals to modulate the acetate metabolism.