Synthetic PPR proteins: a tool to rewrite RNA sequences
RNA publishing is a natural process that changes RNA after its transcription, that is to say after it was produced from DNA. In plants, this modification is essential in chloroplasts and mitochondria so that proteins work properly. The accuracy of this mechanism is ensured by RNA binding proteins called PPR for Pentatricopeptide repeat. They guide the enzymes allowing publishing to the target bases of RNA. However, these PPR proteins are not very flexible and cannot be easily modified to target precise parts of DNA.
In a study published in the journal Nucleic Acids Researchscientists have used Synthetic PPR proteinscapable of being programmed to target specific RNA sites in mitochondria and plant chloroplasts. Unlike natural publishing factors, which have a fixed specificity, these reprogrammable (DPPRE) proteins can be adjusted to recognize any RNA sequence.
A promising application in plant biotechnology
To achieve this, scientists have combined different areas of the PPR protein capable of binding on specific RNA sequences, with an enzyme capable of modifying one of the bases composing RNA, Cytidine, in another basis, Uridine. They can thus modify the sequence of the RNA and induce controlled mutations. Thanks to this technology, they were able to induce specific modifications of target RNAs in the organeness of a model plant: Nicotiana benthamiana and obtained remarkable publishing rates.
One of the major advances in this work lies in the ability to reprogram the PPR proteins, to target a wide variety of RNA sequences. This opens the way to many modifications, such as targeted modification of genes, improving plant crops and protein production in plant organelles.
In summary, this approach based on synthetic PPR proteins makes it possible to precisely rewrite genetic information in plants, with important implications for biotechnology and sustainable agriculture.
