Aug 13, 2015

Protein acetylation dynamics in response to carbon overflow in Escherichia coli

Molecular Microbiology
B SchillingAlan J Wolfe

Abstract

In Escherichia coli, acetylation of proteins at lysines depends largely on a non-enzymatic acetyl phosphate-dependent mechanism. To assess the functional significance of this post-translational modification, we first grew wild-type cells in buffered tryptone broth with glucose and monitored acetylation over time by immunochemistry. Most acetylation occurred in stationary phase and paralleled glucose consumption and acetate excretion, which began upon entry into stationary phase. Transcription of rprA, a stationary phase regulator, exhibited similar behavior. To identify sites and substrates with significant acetylation changes, we used label-free, quantitative proteomics to monitor changes in protein acetylation. During growth, both the number of identified sites and the extent of acetylation increased with considerable variation among lysines from the same protein. As glucose-regulated lysine acetylation was predominant in central metabolic pathways and overlapped with acetyl phosphate-regulated acetylation sites, we deleted the major carbon regulator CRP and observed a dramatic loss of acetylation that could be restored by deleting the enzyme that degrades acetyl phosphate. We propose that acetyl phosphate-dependent acetylati...Continue Reading

Mentioned in this Paper

Metabolic Process, Cellular
Buffers
Gene Expression Regulation, Bacterial
acetyl phosphate
Alkalescens-Dispar Group
Metabolic Networks and Pathways
Post-Translational Protein Processing
Transcription, Genetic
Vitreous Carbon
Phosphate Measurement

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