@article{89821,
  keywords = {Cold Temperature, Mutation, Escherichia coli, Microbial Sensitivity Tests, Gene Expression Regulation, Bacterial, Recombinant Fusion Proteins, Escherichia coli Proteins, Culture Media, Maltose, Bacterial Outer Membrane Proteins, Receptors, Virus, Suppression, Genetic, Lac Operon, Porins, Heat-Shock Response, Pyrophosphatases},
  author = {Nicholas Hand and Thomas Silhavy},
  title = {Null mutations in a Nudix gene, ygdP, implicate an alarmone response in a novel suppression of hybrid jamming},
  abstract = {<p>Induction of the toxic LamB-LacZ protein fusion, Hyb42-1, leads to a lethal generalized protein export defect. The prlF1 suppressor causes hyperactivation of the cytoplasmic Lon protease and relieves the inducer sensitivity of Hyb42-1. Since prlF1 does not cause a detectable change in the stability or level of the hybrid protein, we conducted a suppressor screen, seeking factors genetically downstream of lon with prlF1-like phenotypes. Two independent insertions in the ygdP open reading frame relieve the toxicity of the fusion protein and share two additional properties with prlF1: cold sensitivity and the ability to suppress the temperature sensitivity of a degP null mutation. Despite these similarities, ygdP does not appear to act in the same genetic pathway as prlF1 and lon, suggesting a fundamental link between the phenotypes. We speculate that the common properties of the suppressors relate to secretion defects. The ygdP gene (also known as nudH) has been shown to encode a Nudix protein that acts as a dinucleotide oligophosphate (alarmone) hydrolase. Our results suggest that loss of ygdP function leads to the induction of an alarmone-mediated response that affects secretion. Using an epitope-tagged ygdP construct, we present evidence that this response is sensitive to secretion-related stress and is regulated by differential proteolysis of YgdP in a self-limiting manner.</p>
},
  year = {2003},
  journal = {J Bacteriol},
  volume = {185},
  pages = {6530-9},
  month = {11/2003},
  issn = {0021-9193},
  doi = {10.1128/JB.185.22.6530-6539.2003},
  language = {eng},
}