Interaction of the Nitrogen Regulatory Protein GlnB (PII) with Biotin Carboxyl Carrier Protein (BCCP) Controls Acetyl-CoA Levels in the CyanobacteriumSynechocystissp. PCC 6803.
The family of PIIsignal 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 PIIproteins may also be involved in the regulation of fatty acid metabolism, since GlnB proteins from Proteobacteria and fromArabidopsis thalianawere shown to interact with biotin carboxyl carrier protein (BCCP) of acetyl-CoA carboxylase (ACC). In case ofEscherichia coliACCase, this interaction reduces the kcatof acetyl-CoA carboxylation, which should have a marked impact on the acetyl-CoA metabolism. In this study we show that the PIIprotein of a unicellular cyanobacterium inhibits the biosynthetic activity ofE. coliACC and also interacts with cyanobacterial BCCP in an ATP and 2-oxoglutarate dependent manner. In a PIImutant strain ofSynechocystisstrain 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.
Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Eberhard-Karls-Universität Tübingen Tübingen, Germany.
Waldemar
W
Hauf
Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Eberhard-Karls-Universität Tübingen Tübingen, Germany.
Katharina
K
Schmid
Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná Curitiba, Brazil.
Edileusa C M
EC
Gerhardt
Departamento de Bioquímica e Biologia Molecular, Universidade Federal do ParanáCuritiba, Brazil; Setor Litoral, Universidade Federal do ParanáMatinhos, Brazil.
Luciano F
LF
Huergo
Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Eberhard-Karls-Universität Tübingen Tübingen, Germany.
Karl
K
Forchhammer
BCCP; GlnB (PII); Synechocystis sp. PCC 6803; acetyl-CoA; cyanobacteria