New horizons for (p)ppGpp in bacterial and plant physiology.
A hyperphosphorylated guanosine nucleotide, (p)ppGpp, was initially identified as the effector molecule responsible for the stringent response in Escherichia coli. However, a rapidly growing number of reports proves that (p)ppGpp-mediated regulation is conserved in many bacteria and even in plants. It is now clear that (p)ppGpp acts as a global regulator during physiological adaptation of the organism to a plethora of environmental conditions. Adaptation is not only essential for surviving periods of stress and nutrient exhaustion but also for the interaction of bacteria with their eukaryotic host, as observed during pathogenesis and symbiosis, and for bacterial multicellular behaviour. Recently, there have been several new discoveries about the effects of (p)ppGpp levels, balanced by RelA-SpoT homologue proteins, in diverse organisms.
Braeken
Kristien
K
Centre of Microbial and Plant Genetics, Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, B-3001 Leuven, Belgium.
Moris
Martine
M
Daniels
Ruth
R
Vanderleyden
Jos
J
Michiels
Jan
J
D017360:Arabidopsis / Q000502:physiology; D018407:Bacterial Physiological Phenomena; D004926:Escherichia coli / Q000502:physiology; D006158:Guanosine Pentaphosphate / Q000502:physiology*; D008025:Ligases / Q000502:physiology; D018521:Plant Physiological Phenomena
D006158:Guanosine Pentaphosphate; D008025:Ligases; C028812:guanosine 3',5'-polyphosphate synthetases