A New Study Finds Surprising Connection Of Nucleic Acids With Fats
Every cell on the earth is encased in a fatty layer of lipids. Lipid membranes safeguard the contents of cells, including genetic material such as RNA and DNA, from harm. New study from the Technical University of Dresden's (TU Dresden) B CUBE – Center for Molecular Bioengineering has revealed how lipids and RNA may directly interact, and how this may influence RNA activity in unanticipated ways. The study's results may contribute to a better understanding of how RNA is regulated in primordial or synthetic biological systems, as well as the creation of better RNA vaccines.
Nucleic acid is a family of macromolecules that may be found in all cells and viruses and plays a vital role in their replication. Aspects of nucleic acids' activities have to do with the storage and expression of genetic information, respectively. Deoxyribonucleic acid (DNA) is a nucleic acid that encodes the information that cells require in order to produce proteins.
A nucleotide consists of three parts: a nitrogenous base, a pentose sugar, and one or more phosphate groups. The carbon residues in pentose are labelled 1′ through 5′. (the prime distinguishes these residues from those in the base, which are numbered without using a prime notation). The base is joined to the ribose at the 1′ position, while the phosphate is attached at the 5′ position. When a polynucleotide is created, the arriving nucleotide's 5′ phosphate bonds to the 3′ hydroxyl group at the end of the expanding chain. Nucleotides contain two forms of pentose: deoxyribose (found in DNA) and ribose (found in RNA). Deoxyribose has a similar structure to ribose, but instead of an OH at the 2′ position, it contains an H. Bases are classified into two types: purines and pyrimidines. Purines have two rings, whereas pyrimidines have a single ring.
The two main types of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). DNA is the genetic substance found in all living species, from bacteria to multicellular animals. It can be present in eukaryotic nuclei, chloroplasts, and mitochondria. In prokaryotes, the DNA is free-floating inside the cytoplasm rather than contained in a membrane envelope.
Tomasz Czerniak and James Sáenz showed that lipids may directly influence the activity of RNA in a basic synthetic system in a recent study published in the journal PNAS. "This opens up an entirely new way of thinking about how we may employ RNA-lipid interactions for bioengineering, for example, delivery of mRNA therapeutics," explains Dr. James Sáenz, senior author of the paper and research group head at the B CUBE — Center for Molecular Bioengineering. Furthermore, their studies can serve to provide light on the origins of ancient life.
A prominent theory on the beginning of life holds that self-replicating RNA molecules gave rise to life years before the emergence of DNA and proteins. In this case, the simple and efficient modulation of RNA activity would be critical for the organization of early life on an old Earth. The researchers investigated how different kinds of RNA molecules interacted with lipid membranes. They discovered that some RNAs bind lipids better than others and that this was dependent on the RNA molecule's sequence and structure. Guanine, one of the four building units of RNA, was very important for RNA to adhere to the lipids. Adding more guanine chains to the RNAs made them stickier, allowing the researchers to adjust the intensity of RNA-lipid connections. It was discovered that guanine not only increased RNA-lipid binding directly but also made it stickier by stimulating the folding of RNAs into various structures. A G-quadruplex is a kind of structure found in cells that are known to be a significant component of RNA activity and regulation." This suggests that RNA-lipid interactions may still occur in current cells, maybe as a vestige of a long-extinct RNA-lipid world "Sáenz said.
After discovering how to tailor RNA to cling better to lipids, the researchers demonstrated that such RNA-lipid interactions might be utilized to modulate the activity of RNAs that catalyze chemical events. "I'm not aware of anyone else demonstrating sequence-specific impacts in the way a lipid may influence RNA catalysis," adds Professor Gerald Joyce of the Salk Institute for Biological Studies in California, who was not involved in the work.