An RNA key that unlocks innate immunity

October 12, 2018

RNA has long been the neglected middle child of biomolecules, the go-between between DNA, which encodes the cell's instructions, and proteins, which carry them out. Increasingly, though, researchers are recognizing RNA as a versatile molecule with, possibly, as many functions as proteins have. New research from Emory University, published in the Journal of Biological Chemistry, shows that one such versatile RNA molecule may be a key player in human cells' frontline defenses against viruses.

Graeme Conn, the biochemistry professor who oversaw the work, studies how RNA is involved in the body's responses to infections. When a human cell senses a virus, it activates a signaling pathway: a protein called OAS gets turned on and produces a signaling molecule, which in turn activates another protein that both directly defends against the virus as well as activating other parts of the cell's innate immune system.

As it turns out, human RNA might play an important role in this pathway, specifically a human RNA molecule called nc886. The "nc" stands for "noncoding," which means this RNA molecule is not carrying instructions for building a protein. It's doing something all on its own.

What it's doing, the new paper shows, is turning on OAS, thus setting off the chain of events that destroys viruses.

"We saw that (nc886) wasn't just an activator of this pathway, but a very potent activator," said Brenda Calderon, who carried out the research as a graduate student in Conn's lab.

The nc886 molecule can adopt two different shapes, and one of them is much better at activating OAS than the other. This is another way in which this RNA molecule acts like a protein: its function depends strongly on its 3-D shape and structure. Although nc886 is present in all human cells, it's unknown whether the relative abundance of the immune-activating and less-active form might change in response to infection.

"We'll be asking these questions about infected and uninfected cells," Conn said. "How does the level of the RNA change? How do the levels of these two (forms) change?"

Getting deep into the molecular details of cells' first responses to viruses opens the door to new kinds of treatments. Calderon speculates that understanding the factors that activate this pathway may enable researchers to someday manipulate it to strengthen antiviral defenses.

"Such approaches have the potential to underpin novel, broad antiviral therapies (that don't rely) on acquired immunity, and therefore are suitable for infants, elderly, and immunocompromised patients," Calderon said.
-end-
The study was funded by the National Institutes of Health and Emory University.

About the Journal of Biological Chemistry

JBC is a weekly peer-reviewed scientific journal that publishes research "motivated by biology, enabled by chemistry" across all areas of biochemistry and molecular biology. The read the latest research in JBC, visit http://www.jbc.org/.

About the American Society for Biochemistry and Molecular Biology

The ASBMB is a nonprofit scientific and educational organization with more than 12,000 members worldwide. Most members teach and conduct research at colleges and universities. Others conduct research in various government laboratories, at nonprofit research institutions and in industry. The Society's student members attend undergraduate or graduate institutions. For more information about ASBMB, visit http://www.asbmb.org.

American Society for Biochemistry and Molecular Biology

Related Protein Articles from Brightsurf:

The protein dress of a neuron
New method marks proteins and reveals the receptors in which neurons are dressed

Memory protein
When UC Santa Barbara materials scientist Omar Saleh and graduate student Ian Morgan sought to understand the mechanical behaviors of disordered proteins in the lab, they expected that after being stretched, one particular model protein would snap back instantaneously, like a rubber band.

Diets high in protein, particularly plant protein, linked to lower risk of death
Diets high in protein, particularly plant protein, are associated with a lower risk of death from any cause, finds an analysis of the latest evidence published by The BMJ today.

A new understanding of protein movement
A team of UD engineers has uncovered the role of surface diffusion in protein transport, which could aid biopharmaceutical processing.

A new biotinylation enzyme for analyzing protein-protein interactions
Proteins play roles by interacting with various other proteins. Therefore, interaction analysis is an indispensable technique for studying the function of proteins.

Substituting the next-best protein
Children born with Duchenne muscular dystrophy have a mutation in the X-chromosome gene that would normally code for dystrophin, a protein that provides structural integrity to skeletal muscles.

A direct protein-to-protein binding couples cell survival to cell proliferation
The regulators of apoptosis watch over cell replication and the decision to enter the cell cycle.

A protein that controls inflammation
A study by the research team of Prof. Geert van Loo (VIB-UGent Center for Inflammation Research) has unraveled a critical molecular mechanism behind autoimmune and inflammatory diseases such as rheumatoid arthritis, Crohn's disease, and psoriasis.

Resurrecting ancient protein partners reveals origin of protein regulation
After reconstructing the ancient forms of two cellular proteins, scientists discovered the earliest known instance of a complex form of protein regulation.

Sensing protein wellbeing
The folding state of the proteins in live cells often reflect the cell's general health.

Read More: Protein News and Protein Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.