Systematic identification of (p)ppGpp-dependent multidrug and stress tolerance factors

Project Information

PERSIST

Grant agreement ID: 707138

DOI

10.3030/707138

Project closed

EC signature date 8 March 2016

Start date 1 April 2016

End date 31 March 2018

Funded under

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Total cost

€ 212 194,80

EU contribution

€ 212 194,80

Coordinated by

KOBENHAVNS UNIVERSITET
Denmark

Periodic Reporting for period 1 - PERSIST (Systematic identification of (p)ppGpp-dependent multidrug and stress tolerance factors)

Reporting period: 2016-04-01 to 2018-03-31

Summary of the context and overall objectives of the project

Chronic and recurrent infections are often caused by multidrug tolerant bacteria, also called persisters, which cause a global healthcare crisis to be addressed urgently. The bacterial “alarmone” molecule (p)ppGpp has been shown to play central roles in persister cell formation. Deep understanding of the underlying mechanisms is anticipated to provide valuable insights which could be exploited to counteract persistent bacterial cells. However, the exact mechanisms operating remain largely unknown. This project aims to address this issue by identifying (p)ppGpp binding proteins (objective 1) and genes required for persistence formation (objective 2) in the model organism E. coli. Overall, many novel (p)ppGpp binding proteins were identified and further investigation of these proteins/genes in persistence formation (objective 3) are undergoing.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

As to Objective 1, systematic screen of (p)ppGpp binding proteins was performed and 12 new proteins, representing one third more of total (p)ppGpp binding proteins, were identified. The research results out of this objective were disseminated to peers via conference attending and the general public via social media (Tweeter, Linkedin, Kudos). This work has been published in mBio, an open access journal, to encourage more scientific communications.
On the other hand, obstacles occurred to Objective 2. Inconsistent and irreproducible results were obtained, precluding further analysis in a conclusive manner. Considering the limited time of this fellowship and the significant progress in Objective 1, we decided to postpone Objective 2 and focus on in-depth studies of identified (p)ppGpp binding proteins and their potential roles in mediating persister cell formation (Objective 3).

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

Objective 1 was fully accomplished, while Objective 2 is postponed. Regarding Objective 3, we currently focus on deciphering the molecular mechanism that (p)ppGpp affect several target proteins. A manuscript is in preparation where we describe a novel mechanism that bacteria use to quickly adapt to stress conditions and therefore promote survival. Conferences are planned to disseminate the result as well.
The identification and further characterization of new (p)ppGpp binding proteins discovered in this project are expected to generate more insights about how (p)ppGpp enhance bacterial survival upon various stresses. Such insights are very important in suggesting new drug targets upon which alternative antimicrobials could be developed. These further researches are therefore highly relevant to the general public and the results will be disseminated via social media and official presses.

Identified novel and known targets of (p)ppGpp in E. coli