Cell-type specific modification of PII is involved in the regulation of nitrogen metabolism in the cyanobacterium Anabaena PCC 7120.
In the heterocystous cyanobacterium Anabaena PCC 7120, the modification state of the signalling PII protein is regulated according to the nitrogen regime of the cells, as already observed in some unicellular cyanobacteria. However, during the adaptation to diazotrophic growth conditions, PII is phosphorylated in vegetative cells while unphosphorylated in heterocysts. Isolation of mutants affected on PII modification state and analysis of their phenotypes allow us to show the implication of PII in the regulation of molecular nitrogen assimilation and more specifically, the requirement of unmodified state of PII in the formation of polar nodules of cyanophycin in heterocysts.
Laurent
Sophie
S
Laboratoire de Chimie Bactérienne, CNRS-UPR9043, 31 Chemin Joseph Aiguier, 13402 Marseille cedex 20, France.
Forchhammer
Karl
K
Gonzalez
Leticia
L
Heulin
Thierry
T
Zhang
Cheng-Cai
CC
Bédu
Sylvie
S
D017033:Anabaena / Q000166:cytology / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D009154:Mutation; D009584:Nitrogen / Q000378:metabolism*; D009586:Nitrogen Fixation; D009591:Nitrogenase / Q000378:metabolism; D051922:PII Nitrogen Regulatory Proteins; D010766:Phosphorylation; D010940:Plant Proteins / Q000378:metabolism
D029681:Arabidopsis Proteins; D001426:Bacterial Proteins; D051922:PII Nitrogen Regulatory Proteins; C473074:PII protein, Arabidopsis; D010940:Plant Proteins; C024250:cyanophycin; D009591:Nitrogenase; D009584:Nitrogen