Four-stranded DNA-binding protein conserved in plants and animals

That's precisely the point of a new paper by a team of Florida State University researchers who see their discovery as a possible path to future advancements in agriculture and other genetics-friendly fields of study.

Biological Science Assistant Professor Elizabeth Stroupe and Associate Professor Hank Bass, along with molecular biophysics graduate student Mykhailo Kopylov, write in a new Biochemistry paper that the same type of protein works in plants and animals to bind to peculiar DNA structures called G-quadruplexes, or G4 DNA for short.

And they hope this discovery will allow them to better understand how genes in plants work, including how plants are able to adapt to adverse situations such as drought or flooding.

"Animals, humans -- they can just leave their environments if they encounter adverse situations," Kopylov said. "But, plants cannot run away if there is drought or flooding. They have to learn how to survive. So, hopefully this protein can show us how the genes work to let plants adapt and survive."

The technical name for that protein is nucleoside diphosphate kinase1 (ZmNDPK1), and it has scientists excited because of its many cellular functions, and the study of its G4 DNA-binding activity may lead to a wider understanding of plant gene regulation.

In humans, that protein regulates hundreds of genes, including ones related to the development of the heart and its health. So, scientists are looking to find what exactly it affects in plants.

"Anytime you find something that is the same in plants and animals, it's really exciting," Stroupe said.

Specifically, ZmNDPK1 was shown to bind tightly to G4 DNA, the structurally unique 4-stranded DNA elements found in thousands of maize genes.

"We didn't originally set out looking for this," Bass said. "It really was a discovery we made along the way and shows the value of collaborative research.

Most people know of DNA as two connected strands arranged in a double helix. Those strands must also occasionally separate to activate or replicate genes. Exactly how specific DNA sequences can adopt transient non-duplex forms, such as G4s, represents an exciting new research area -- trying to figure out how these may function as tiny molecular gene switches.

In humans, G4 DNA is present in genes that regulate cancer and cell division. A previously published paper, by Bass, Kopylov, Stroupe and their collaborators characterized these same structures as pervasive throughout the maize genome. Building on that study, the group defined the first known plant G4-binding protein, moving from plant genetics to biochemistry and structural biology.

"Now that we have evidence for the partnership in both animals and plants, we are in a unique position to compare the functional importance of G4 DNA as conserved genetic regulatory elements," Stroupe said.