Study reveals plants have protein monitoring mechanism thought to exist only in animal cells

Plants have a sophisticated mechanism for monitoring the production of new proteins. The U1 snRNP complex ensures that protein blueprints are fully completed. This is important because cells tend to terminate the process prematurely. This type of quality control, called telescripting, was previously known to only exist in animal cells.

A research team led by the Martin Luther University Halle-Wittenberg (MLU) has now shown that a similar process also occurs in plants. The study was published in the journal Natural plants.

Plant cells need proteins to function. They control all vital processes of the plant, for example growth and metabolism. The blueprint for new proteins lies in a plant’s genetic material, or more precisely its genes.

“The information is encoded and the genes have to be read and transcribed from DNA into RNA. These RNA molecules constitute the blueprint for the proteins, the step-by-step assembly instructions,” explains Professor Sascha Laubinger, plant geneticist at the MLU.

In the new study, their team investigated how factories ensure these plans are produced correctly. “RNA also contains sections that are not necessary for the production of proteins. These must be recognized and removed beforehand. This is done by a spliceosome, which also connects the relevant genetic information,” continues Laubinger.

There is no room for error in this process: even minor changes to RNA can result in defective proteins. Genes also have several sites where the transcription process can be unintentionally interrupted.

About 10 years ago, researchers discovered a mechanism in animals that keeps the transcription of DNA into RNA in progress: telescripting.

“The U1 snRNP complex has a dual function: as an integral part of the spliceosome, it helps ensure that the relevant genetic information is assembled correctly. It also ensures that the transcription process is fully completed. This second mechanism is known as telescript name,” explains Laubinger. Until now, it was unclear whether this process also existed in plants.

To test their hypothesis, the researchers used the model plant Arabidopsis thaliana. They artificially produced plants in the laboratory containing few snRNP U1 molecules. “We managed to reduce the concentration to about 10% of the normal amount. Anything below that meant the plant would no longer be viable,” says Laubinger.

Visually, the plants already differed greatly from their normal counterparts: they were significantly smaller and their leaves were stunted. The researchers analyzed the activity of all the genes in these plants and looked for shortened RNA snippets. This indicates that transcription of DNA into RNA was prematurely terminated.

The team found several hundred cases. “We were surprised to have found so many RNA fragments. Arabidopsis thaliana has relatively short genes, so the influence of the U1 snRNP complex on the transcription process should be rather weak. Other plants, such as some ferns and pines, have longer genes, so the effect could be even greater,” says Laubinger.

The results provide important insights into how gene activity in plants can be controlled. “We know that telescripting can change gene activity in human cells under heat stress,” says Laubinger. If something similar could be found in plants, it could be a way to make them more resilient to the effects of climate change, for example.