AUTHOR=Hauf Waldemar , Schmid Katharina , Gerhardt Edileusa C. M. , Huergo Luciano F. , Forchhammer Karl 

TITLE=Interaction of the Nitrogen Regulatory Protein GlnB (PII) with Biotin Carboxyl Carrier Protein (BCCP) Controls Acetyl-CoA Levels in the Cyanobacterium Synechocystis sp. PCC 6803

JOURNAL=Frontiers in Microbiology

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.01700

DOI=10.3389/fmicb.2016.01700

ISSN=1664-302X

ABSTRACT=<p>The family of P<sub>II</sub> signal transduction proteins (members GlnB, GlnK, NifI) plays key roles in various cellular processes related to nitrogen metabolism at different functional levels. Recent studies implied that P<sub>II</sub> proteins may also be involved in the regulation of fatty acid metabolism, since GlnB proteins from Proteobacteria and from <italic>Arabidopsis thaliana</italic> were shown to interact with biotin carboxyl carrier protein (BCCP) of acetyl-CoA carboxylase (ACC). In case of <italic>Escherichia coli</italic> ACCase, this interaction reduces the k<sub>cat</sub> of acetyl-CoA carboxylation, which should have a marked impact on the acetyl-CoA metabolism. In this study we show that the P<sub>II</sub> protein of a unicellular cyanobacterium inhibits the biosynthetic activity of <italic>E. coli</italic> ACC and also interacts with cyanobacterial BCCP in an ATP and 2-oxoglutarate dependent manner. In a P<sub>II</sub> mutant strain of <italic>Synechocystis</italic> strain PCC 6803, the lacking control leads to reduced acetyl-CoA levels, slightly increased levels of fatty acids and formation of lipid bodies as well as an altered fatty acid composition.</p>