Navigation Links
RNA-associated introns guide nerve-cell channel production

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

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.

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.

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 doesnt mean that it doesnt 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.

Contact: Karen Kreeger
University of Pennsylvania School of Medicine

Related medicine news :

1. New Guideline Urges Screening for Fall Risk
2. New IDSA Clinical Practice Guidelines Recommend NOXAFIL(R) (Posaconazole) for Antifungal Prophylaxis in Certain High-Risk Patients
3. Government dietary guidelines, unintended consequences and public policy
4. Doctors Review End-of-Life Care Guidelines
5. AHRQ Releases Consumer Financial Incentives Guide for Employers and Other Health Care Purchasers
6. ASGE offers guidelines on endoscopic treatment of dyspepsia
7. Tufts researchers update their food guide pyramid for older adults
8. Alexian Brothers Hospital Network Receives American Stroke Associations Get with the Guidelines Silver Achievement Award
9. Alexian Brothers Hospital Network Receives American Stroke Associations Get With the Guidelines Achievement Award
10. With Obesity, Diabetes, and Cardiovascular Disease on the Rise, Physicians Need More Comprehensive Guidelines
11. Group Seeks Refinement of Knee Arthritis Treatment Guidelines
Post Your Comments:
Related Image:
RNA-associated introns guide nerve-cell channel production
(Date:11/30/2015)... DC (PRWEB) , ... November ... ... Inc. (AIS) is pleased to announce the speakers for “Value-Based Payer-Provider Partnerships: ... lessons learned from three innovative value-based care arrangements: Essentia Health and UCare, ...
(Date:11/30/2015)... ... November 30, 2015 , ... ... around Novus’ TIGR® Matrix Surgical Mesh technology for soft tissue repair in the ... Matrix is a long-term resorbable surgical mesh intended to support and reinforce soft ...
(Date:11/30/2015)... Puerto Rico (PRWEB) , ... November 30, 2015 , ... ... active part of the San Juan Beauty Show held on November 8th and 9th ... was attended by media personalities, hair artists, renowned beauticians and top of the line ...
(Date:11/30/2015)... ... November 30, 2015 , ... ... are pleased to announce their strategic partnership at the Radiological Society of ... Service, Inc., and Winscribe, global providers of cutting-edge dictation and speech-enabled documentation ...
(Date:11/30/2015)... ... 30, 2015 , ... World Patent Marketing , a ... household invention that provides an economical and easy way of gaining customized curtains. ... at 2.6%," says Scott Cooper, CEO and Creative Director of World Patent Marketing. ...
Breaking Medicine News(10 mins):
(Date:11/30/2015)... Nov. 30, 2015   VolitionRx Limited (NYSE MKT: ... tests for a broad range of cancer types and other ... Micro Conference, which will be held December 1 - 3 in ... VolitionRx will be David Kratochvil , Chief Financial Officer ... Investor Relations. ® blood-based tests for colorectal ...
(Date:11/30/2015)... , November 30, 2015 PFE ... at up to 10 G protein-coupled receptor (GPCR) targets ... to research and develop potential new medicines directed at ... multiple therapeutic areas. --> Heptares Therapeutics ("Heptares"), ... and wholly-owned subsidiary of Sosei Group Corporation ("Sosei"; TSE ...
(Date:11/30/2015)... and REHOVOT, Israel , ... specialty pharmaceutical company focused on acquiring and developing innovative ... announced the appointment of Keith A. Katkin ... Gregory J. Flesher , chief executive officer for ... building successful organizations.  As chairman, he will be able ...
Breaking Medicine Technology: