Project

Characterisation of novel prokaryotic Argonaute Systems

Prokaryotes are under constant threat of invading nucleic acids such as viruses and plasmids. To withstand infection by these nucleic acids, prokaryotes have evolved different host-defense mechanisms such as restriction modification systems, abortive infection systems, CRISPR-Cas system and the recently discover prokaryotic Argonautes (pAgo). This research will focus on the characterization of the molecular mechanisms and function of unexplored pAgos.

Background

In humans and other animals and plants (eukaryotes), immune systems protect their host against bacteria, viruses and other invaders. Bacteria and archaea (prokaryotes) also have to protect themselves against viruses (phages) and against other mobile genetic elements (MGEs), such as plasmids and transposons. Such MGEs are a metabolic burden and cause a fitness disadvantage. To prevent uptake and/or propagation of MGEs, prokaryotes have evolved various immune systems, including CRISPR-Cas and Restriction-Modification systems.  

Argonaute proteins can be found in both prokaryotes and eukaryotes. In eukaryotes Argonaute proteins (eAgos) are involved in RNA interference. Here, Argonaute proteins use an RNA guide to cleave or facilitate degradation of a target RNA that is complementary to the RNA guide. This targeted degradation of RNAs by eAgos underlies post-transcriptional gene silencing, but it can also be important for interference with MGEs such as transposons and RNA viruses. While eAgos only bind RNA guides and targets, certain prokaryotic Argonaute homologs (pAgos) can also bind DNA guides and cleave DNA targets. As both eAgos and pAgos function in defence against MGEs, Argonaute proteins are the only known nucleic acid guided immune system that is conserved from prokaryotes to eukaryotes.

Aim of the project

Prokaryotic immune systems have only recently attracted more interest due to the characterization of the CRISPR-Cas systems and their applications in genome editing and therapeutics. While various DNA-guided DNA targeting pAgos have been shown to function as immune systems, the mechanisms behind this targeting and possible other functions are largely unknown. 

We aim to uncover the unknown mechanisms and functions of prokaryotic Argonautes.

Join the project for a bachelor or master thesis

As a thesis student you will:

  • Learn various biochemical, microbial, and biophysical techniques
  • Perform both in vitro & in vivo experiments
  • Perform molecular cloning and express and purify proteins

Contact

Do you have a question about argonautes, or would you like to join us as a student researcher? Please contact us.