Project Details
Projekt
Understanding bacterial epitranscriptomics on the basis of Escherichia coli – T4 phage interactions
Applicant
Dr. Katharina Höfer
Subject Area
Metabolism, Biochemistry and Genetics of Microorganisms
Biochemistry
Biochemistry
Term
since 2021
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 464500427
Based on the potential of phages to kill bacteria, the mechanisms by which viruses hijack their host’s genetic machinery are of enormous interest. Besides the knowledge about phage structure and genome, the dynamics of its transcription and translation apparatus remain poorly understood.For the specific temporal reprogramming of the E. coli transcriptional and translational apparatus, the T4 phage uses three ADP-ribosyltransferases (ADPRTs) (Alt, ModA and ModB) that post-translationally modify proteins. ADPRTs transfer an ADP-ribose fragment from the ubiquitous coenzyme nicotinamide adenine dinucleotide (NAD) to specific acceptor proteins, called ADP-ribosylation. Recently, NAD was identified as a 5’-modification of RNA molecules in bacteria and higher organisms. The identification of NAD as a new RNA-modification might implement a new ‘epitranscriptomic’ layer of cellular regulation in all kingdoms of life. Here, we report that bacteriophage T4 ADPRTs accept not only NAD, but also NAD-RNA as substrate, thereby covalently linking entire RNA chains to acceptor proteins in an “RNAylation” reaction. Our work exemplifies the first direct connection between RNA modification and posttranslational protein modificationConsidering the significant role of ADPRTs for the regulation of ribosome and RNA polymerase activities during viral infections, ADP-ribosylation and RNAylation may have far-reaching implications in bacterial biology. The application of small molecules like NAD or NAD-RNA to regulate transcription and translation in bacteria provides a new epitranscriptomic concept for the cellular organisation and regulation of the viral infection cycle.Here, we propose to characterise the bacterial epitranscriptomics on the basis of T4 phage – E. coli interaction. This inter-disciplinary, fundamental research project will provide first insights into the temporal modulation of the transcriptome and translatome of E. coli infected with T4 phage. By combining different next generation sequencing (NGS) strategies and proteomic approaches, we will study the molecular influence of ADP-ribosylation and RNAylation on the central cellular processes of transcription and translation during E. coli – T4 phage interactions. For these studies, we can make use of a range of methods already established in our group. In our project, we set the foundation to understand the functional role of T4 ADPRTs during the viral infection cycle using T4 phage mutants that express only one functional ADPRT. Moreover, we study how post-translational protein modifications regulate the bacterial and phage transcriptome using NGS. Finally, we characterize the influence of ADP-ribosylation and RNAylation on the regulation of the bacterial translation apparatus. This study will broaden our understanding of how the ADPRTs of the T4 phage (Alt, ModA, and ModB) modulate the bacterial key mechanisms and inhibit bacterial defence mechanisms in order to trigger an effective infection.
DFG Programme
Priority Programmes
