Sirtuin-dependent reversible lysine acetylation of glutamine synthetases reveals an autofeedback loop in nitrogen metabolism

In cells of all domains of life, reversible lysine acetylation modulates the function of proteins involved in central cellular processes such as metabolism. In this study, we demonstrate that the nitrogen regulator GlnR of the actinomycete Saccharopolyspora erythraea directly regulates transcription of the acuA gene (SACE_5148), which encodes a Gcn5-type lysine acetyltransferase. We found that AcuA acetylates two glutamine synthetases (GlnA1 and GlnA4) and that this lysine acetylation inactivated GlnA4 (GSII) but had no significant effect on GlnA1 (GSI-β) activity under the conditions tested. Instead, acetylation of GlnA1 led to a gain-of-function that modulated its interaction with the GlnR regulator and enhanced GlnR-DNA binding. It was observed that this regulatory function of acetylated GSI-β enzymes is highly conserved across actinomycetes. In turn, GlnR controls the catalytic and regulatory activities (intracellular acetylation levels) of glutamine synthetases at the transcriptional and posttranslational levels, indicating an autofeedback loop that regulates nitrogen metabolism in response to environmental change. Thus, this GlnR-mediated acetylation pathway provides a signaling cascade that acts from nutrient sensing to acetylation of proteins to feedback regulation. This work presents significant new insights at the molecular level into the mechanisms underlying the regulation of protein acetylation and nitrogen metabolism in actinomycetes..

Medienart:

Artikel

Erscheinungsjahr:

2016

Erschienen:

2016

Enthalten in:

Zur Gesamtaufnahme - volume:113

Enthalten in:

Proceedings of the National Academy of Sciences of the United States of America - 113(2016), 24, Seite 6653-6658

Sprache:

Englisch

Beteiligte Personen:

You, Di [VerfasserIn]
Yin, Bin-Cheng [Sonstige Person]
Li, Zhi-Hai [Sonstige Person]
Zhou, Ying [Sonstige Person]
Yu, Wen-Bang [Sonstige Person]
Zuo, Peng [Sonstige Person]
Ye, Bang-Ce [Sonstige Person]

Links:

Volltext
www.ncbi.nlm.nih.gov
search.proquest.com

Themen:

Cellular biology
Enzymes
Metabolism
Nitrogen
Proteins

doi:

10.1073/pnas.1525654113

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

OLC1978652003