Accession Number : AD1010889


Title :   Persistence Increases in the Absence of the Alarmone Guanosine Tetraphosphate by Reducing Cell Growth


Descriptive Note : Journal Article


Corporate Author : Pennsylvania State University University Park United States


Personal Author(s) : Chowdhury,Nityananda ; Kwan,Brian W ; Wood,Thomas K


Full Text : http://www.dtic.mil/get-tr-doc/pdf?AD=AD1010889


Report Date : 16 Aug 2016


Pagination or Media Count : 9


Abstract : Most bacterial cells are stressed, and as a result, some become tolerant to antibiotics by entering a dormant state known as persistence. The key intracellular metabolite that has been linked to this persister state is guanosine tetraphosphate (ppGpp), the alarmone that was first linked to nutrient stress. In Escherichia coli, ppGpp redirects protein production during nutrient stress by interacting with RNA polymerase directly and by inhibiting several proteins. Consistently, increased levels of ppGpp lead to increased persistence; but, the mechanism by which elevated ppGpp translates into persistence has not been determined. Hence, we explored persistence in the absence of ppGpp so that the underlying mechanism of persister cell formation could be explored. We found that persister cells still form, although at lower levels, in the absence of ppGpp. Additionally, the toxin/antitoxin systems that we investigated (MqsR, MazF, GhoT, and YafQ) remain able to increase persistence dramatically in the absence of ppGpp. By overproducing each E. coli protein from the 4287 plasmid vectors of the ASKA library and selecting for increased persistence in the absence of ppGpp (via a relA spoT mutant), we identified five new proteins, YihS, PntA, YqjE, FocA, and Zur, that increase persistence simply by reducing cell growth.


Descriptors :   bacterial infections , cells(biology) , Toxins and antitoxins , Escherichia coli , proteins , inhibition


Distribution Statement : APPROVED FOR PUBLIC RELEASE