Methyl marks on RNA discovered to be key to brain cell connections

August 10, 2018, University of California, Los Angeles
Credit: CC0 Public Domain

Methyl chemical groups dot lengths of DNA, helping to control when certain genes are accessible by a cell. In new research, UCLA scientists have shown that at the connections between brain cells—which often are located far from the central control centers of the cells—methyl groups also dot chains of RNA. This methyl markup of RNA molecules is likely key to brain cells' ability to quickly send signals to other cells and react to changing stimuli in a fraction of a second.

To dictate the biology of any cell, DNA in the cell's nucleus must be translated into corresponding strands of RNA. Next, the messenger RNA, or mRNA—an intermediate genetic molecule between DNA and proteins—is transcribed into proteins. If a cell suddenly needs more of a —to adapt to an incoming signal, for instance—it must translate more DNA into mRNA. Then it must make more proteins and shuttle them through the cell to where they are needed. This process means that getting new proteins to a distant part of a cell, like the of neurons where signals are passed, can take time.

Research has recently suggested that chemical groups, which can control when DNA is transcribed into mRNA, are also found on strands of mRNA. The methylation of mRNA, researchers hypothesize, adds a level of control to when the mRNA can be translated into proteins, and their occurrence has been documented in a handful of organs throughout the bodies of mammals. The pattern of methyls on mRNA in any given cell is dubbed the "epitranscriptome."

UCLA and Kyoto University researchers mapped out the location of methyls on mRNA found at the synapses, or junctions, of mouse . They isolated brain from adult mice and compared the epitranscriptome found at the synapses to the epitranscriptomes of mRNA elsewhere in the cells. At more than 4,000 spots on the genome, the mRNA at the synapse was methylated more often. More than half of these spots, the researchers went on to show, are in genes that encode proteins found mostly at the synapse. The researchers found that when they disrupted the methylation of mRNA at the synapse, the brain cells didn't function normally.

The methylation of mRNA at the synapse is likely one of many ways that neurons speed up their ability to send messages, by allowing the mRNA to be poised and ready to translate into proteins when needed.

The levels of key proteins at synapses have been linked to a number of psychiatric disorders, including autism. Understanding how the epitranscriptome is regulated, and what role it plays in biology, may eventually provide researchers with a new way to control the proteins found at synapses and, in turn, treat disorders characterized by synaptic dysfunction.

Explore further: Witnessing the birth of a tiny RNA at brain synapses

More information: Daria Merkurjev et al. Synaptic N6-methyladenosine (m6A) epitranscriptome reveals functional partitioning of localized transcripts, Nature Neuroscience (2018). DOI: 10.1038/s41593-018-0173-6

Related Stories

Witnessing the birth of a tiny RNA at brain synapses

February 13, 2017

Proteins are the building blocks of all cells. They are made from messenger RNA (mRNA) molecules, which are copied from DNA in the nuclei of cells. All cells, including brain cells regulate the amount and kind of proteins ...

Mixed mRNA tails act like a shield to delay its shortening

July 20, 2018

Cells curb the amount of specific proteins at any desired time via the control of mRNA degradation. As mRNA nucleotides tail plays a role in this process, biologists at the Center for RNA Research, within the Institute for ...

Recommended for you

Meteorite source in asteroid belt not a single debris field

February 17, 2019

A new study published online in Meteoritics and Planetary Science finds that our most common meteorites, those known as L chondrites, come from at least two different debris fields in the asteroid belt. The belt contains ...

Diagnosing 'art acne' in Georgia O'Keeffe's paintings

February 17, 2019

Even Georgia O'Keeffe noticed the pin-sized blisters bubbling on the surface of her paintings. For decades, conservationists and scholars assumed these tiny protrusions were grains of sand, kicked up from the New Mexico desert ...

Archaeologists discover Incan tomb in Peru

February 16, 2019

Peruvian archaeologists discovered an Incan tomb in the north of the country where an elite member of the pre-Columbian empire was buried, one of the investigators announced Friday.

Where is the universe hiding its missing mass?

February 15, 2019

Astronomers have spent decades looking for something that sounds like it would be hard to miss: about a third of the "normal" matter in the Universe. New results from NASA's Chandra X-ray Observatory may have helped them ...

What rising seas mean for local economies

February 15, 2019

Impacts from climate change are not always easy to see. But for many local businesses in coastal communities across the United States, the evidence is right outside their doors—or in their parking lots.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.