Featured Research

from universities, journals, and other organizations

Some 'Junk' DNA Is Important Guide For Nerve-cell Channel Production

Date:
February 11, 2008
Source:
University of Pennsylvania School of Medicine
Summary:
Researchers have discovered that introns, or junk DNA to some, associated with RNA are an important molecular guide to making nerve-cell electrical channels. They hope to relate this knowledge to understanding the molecular underpinnings of memory and learning, as well as components of cognitive dysfunction resulting from neurological disease.

Image of a neuron. Dendrites (highlighted by arrows), which branch from the cell body of the neuron, detect the electrical and chemical signals transmitted to the neuron by the axons of other neurons.
Credit: Kevin Miyashiro and James Eberwine, PhD, University of Pennsylvania School of Medicine

Researchers at the University of Pennsylvania School of Medicine have discovered that introns, or junk DNA to some, associated with RNA are an important molecular guide to making nerve-cell electrical channels. In nerve cells, some ion channels are located in the dendrite, which branch from the cell body of the neuron. Dendrites detect the electrical and chemical signals transmitted to the neuron by the axons of other neurons. Abnormalities in the dendrite electrical channel are involved in epilepsy, neurodegenerative diseases, and cognitive disorders, among others.

Related Articles


Introns are commonly looked on as sequences of "junk" DNA found in the middle of gene sequences, which after being made in RNA are simply excised in the nucleus before the messenger RNA is transported to the cytoplasm and translated into a protein. In 2005, the Penn group first found that dendrites have the capacity to splice messenger RNA, a process once believed to only take place in the nucleus of cells.

Now, in the current study, the group has found that an RNA encoding for a nerve-cell electrical channel, called the BK channel, contains an intron that is present outside the nucleus. This intron plays an important role in ensuring that functional BK channels are made in the appropriate place in the cell.

Senior author James Eberwine, PhD, Elmer Bobst Professor of Pharmacology, and lead authors Kevin Miyashiro, and Thomas J. Bell, PhD, both in Eberwine's lab, report their findings in the early online edition of the Proceedings of the National Academy of Sciences February 4.

When this intron-containing RNA was knocked out, leaving the maturely spliced RNA in the cell, the electrical properties of the cell became abnormal. "We think the intron-containing mRNA is targeted to the dendrite where it is spliced into the channel protein and inserted locally into the region of the dendrite called the dendritic spine. The dendritic spine is where a majority of axons from other cells touch a particular neuron to facilitate neuronal communication" says Eberwine. "This is the first evidence that an intron-containing RNA outside of the nucleus serves a critical cellular function."

"The intron acts like a guide or gatekeeper," says Eberwine. "It keys the messenger RNA to the dendrite for local control of gene expression and final removal of the intron before the channel protein is made. Just because the intron is not in the final channel protein doesn't mean that it doesn't have an important purpose."

The group surmises that the intron may control how many mRNAs are brought to the dendrite and translated into functional channel proteins. The correct number of channels is just as important for electrical impulses as having a properly formed channel.

The investigators believe that this is a general mechanism for the regulation of cytoplasmic RNAs in neurons. Given the central role of dendrites in various physiological functions they hope to relate this new knowledge to understanding the molecular underpinnings of memory and learning, as well as components of cognitive dysfunction resulting from neurological disease.

Co-authors are Jai-Yoon Sul, Peter T. Buckley, Jeanine Jochems, David F. Meaney, Phil Haydon, and Thomas D. Parsons, all from Penn, as well as Charles Cantor from Sequenom Inc. (San Diego) and Ronald McCullough from Boston University.

This work was funded by the National Institute of Mental Health, the National Institute of Child Health and Human Development, the National Institute on Aging and the Health Research Funds of the State of Pennsylvania.


Story Source:

The above story is based on materials provided by University of Pennsylvania School of Medicine. Note: Materials may be edited for content and length.


Cite This Page:

University of Pennsylvania School of Medicine. "Some 'Junk' DNA Is Important Guide For Nerve-cell Channel Production." ScienceDaily. ScienceDaily, 11 February 2008. <www.sciencedaily.com/releases/2008/02/080205115800.htm>.
University of Pennsylvania School of Medicine. (2008, February 11). Some 'Junk' DNA Is Important Guide For Nerve-cell Channel Production. ScienceDaily. Retrieved April 18, 2015 from www.sciencedaily.com/releases/2008/02/080205115800.htm
University of Pennsylvania School of Medicine. "Some 'Junk' DNA Is Important Guide For Nerve-cell Channel Production." ScienceDaily. www.sciencedaily.com/releases/2008/02/080205115800.htm (accessed April 18, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Saturday, April 18, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Our Love Of Puppy Dog Eyes Explained By Science

Our Love Of Puppy Dog Eyes Explained By Science

Newsy (Apr. 17, 2015) Researchers found a spike in oxytocin occurs in both humans and dogs when they gaze into each other&apos;s eyes. Video provided by Newsy
Powered by NewsLook.com
Scientists Find Link Between Gestational Diabetes And Autism

Scientists Find Link Between Gestational Diabetes And Autism

Newsy (Apr. 17, 2015) Researchers who analyzed data from over 300,000 kids and their mothers say they&apos;ve found a link between gestational diabetes and autism. Video provided by Newsy
Powered by NewsLook.com
Video Messages Help Reassure Dementia Patients

Video Messages Help Reassure Dementia Patients

AP (Apr. 17, 2015) Family members are prerecording messages as part of a unique pilot program at the Hebrew Home in New York. The videos are trying to help victims of Alzheimer&apos;s disease and other forms of dementia break through the morning fog of forgetfulness. (April 17) Video provided by AP
Powered by NewsLook.com
Boy or Girl? Intersex Awareness Is on the Rise

Boy or Girl? Intersex Awareness Is on the Rise

AP (Apr. 17, 2015) At least 1 in 5,000 U.S. babies are born each year with intersex conditions _ ambiguous genitals because of genetic glitches or hormone problems. Secrecy and surgery are common. But some doctors and activists are trying to change things. (April 17) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins