It went “click“

It is sophisticated techniques that help researchers to make biological processes in the body visible, and thus understand them better. At the Cells-in-Motion Cluster of Excellence (CiM) at the University of Münster, researchers are developing new ways of marking individual cells and their components so that they become fluorescent, for example, and can be made visible using imaging techniques. CiM Professor Andrea Rentmeister and her team have now succeeded in marking messenger RNA in living cells using, for the first time, click chemistry. This biomolecule plays a decisive role in all of the cell’s functions. The researchers’ long-term aim is to observe the dynamic behaviour of the messenger RNA in order to be able specifically to influence it. The study has been published in the specialist journal “Angewandte Chemie”.

Within the cell, messenger ribonucleic acid (RNA) conveys genetic information for the production of proteins. Proteins, for their part, are the workers in the cell, making all cellular processes possible. The messenger RNA transports the genetic information needed from the nucleus of the cell to the ribosomes in the plasma. These ribosomes are small components in the cell which make contact with the messenger RNA, “translate” the genetic information and thus produce proteins.

The researchers at Münster developed an especially fast, reliable way of modifying messenger RNA with the use of enzymes and marking it with a fluorescent dye. The method they used is based on a concept from click chemistry, which is increasingly being made use of. This enables molecular components to be joined up on the basis of just a few chemical reactions – without producing any unwanted or toxic by-products. Joining up the components is, ultimately, as easy as using press studs – it goes “click”, in a figurative sense. The great challenge in this development is, as biochemist Andrea Rentmeister says, that “living cells react very sensitively to their environment. To mark them, the chemical reaction has be especially gentle.”

As a result of the marking, the researchers were able not only to make the messenger RNA visible, but also to influence it, because at the same time they modified the so-called cap of the messenger RNA. This cap plays an important role in the function and stability of the messenger RNA. The production of proteins decreased as a result of the chemical modification.

With the possibility of modifying the cap with click chemistry, the researchers have created the methodological basis for tracking – and influencing – the paths taken by messenger RNA in living cells. “We’ve now got a foot in the door,” says Rentmeister. In future the researchers aim to refine the marking process still further and examine how they can steer the messenger RNA function in different types of cells in a more targeted way.

Original publication:
Holstein JM, Anhäuser L,Rentmeister A. Modifying the 5’-cap to click eukaryotic mRNA and tune translation efficiency in living cells. Angew. Chem. Int. Ed., DOI: 10.1002/ange.201604107 Abstract