AUG 24, 2015

Mysterious Molecules

WRITTEN BY: Ilene Schneider
While there is a theory that RNA, instead of DNA, is the original building block of all life, many RNA molecules remain mysterious, their true nature and function little understood. With an award of more than $2.5 million from the National Science Foundation’s Plant Genome Research Program, the University of Pennsylvania’s Brian Gregory will join two scientists from the University of Arizona to study the true nature of a class of mysterious RNA molecules known as long non-coding ribonucleic acid molecules (lncRNA), according to a press release
 
The research project, which is expected to take four years, is designed to provide “a greater understanding of this potentially important class of molecules, their biology and their function in the cell nucleus,” said Gregory, an assistant professor of biology in Penn’s School of Arts & Sciences and a leading expert in RNA regulation of cellular processes. Gregory will use a new technique developed in his lab called PIP-seq to isolate lncRNA molecules from the nuclei of plant cells and to visualize genetic material that has never been observed. This group of RNAs, which does not provide genetic code for proteins, functions in numerous biological processes at the cellular level, oftentimes affecting tissues in many organisms.
 
According to Eric Lyons, an assistant professor in the University of Arizona’s College of Agriculture and Life Sciences, who is part of the team, “About 50 years ago the idea emerged that the first molecule of life was RNA, before DNA and before protein. RNA was discovered to be able to not only carry genetic information but also to catalyze biochemical reactions. It’s similar to DNA, but it’s more flexible.”
 
DNA molecules only carry genetic information but are not known to regulate cellular processes. RNA’s flexibility allows it to adopt more complex structures, and hence more diverse functions, than DNA, Lyons said, adding “RNA isn’t just this intermediary of genetic information flowing from the genome into proteins. It has a huge role in the regulation of nearly all cellular processes, including the activity of individual genes, chromosomes and whole genomes.”
 
Mark Beilstein, third team member and also an assistant professor in the School of Plant Sciences at UA’s College of Agriculture and Life Sciences, added, “This is an underappreciated class of genetic elements. While the field of genetics has focused in large part on the functions of genes, investigations into the biology of lncRNA molecules are just now gaining steam. Uncovering the functions of lncRNA molecules is an important next step in elucidating how information flows from genomic DNA to RNA and proteins responsible for carrying out the work of the cell.”
 
The NSF grant will enable the researchers to investigate lncRNA functions in several different plant species, seeking to identify and classify the molecules and to understand their roles in plant cellular processes. Different lncRNA molecules are genetically expressed at different times in a plant’s life cycle, including in response to stressors such as drought or soils with high salt content, Lyons explained.
 
Lyons concluded, “We want to know whether plants under stress make lncRNA molecules to redesign the plant’s gene expression program in response to that stress. It could have huge economic implications for how we could modify plants to be better suited to survive different environmental stresses. As we begin to understand the importance of the regulation of the cell by RNA, we start to see our world expand immensely.”