Featured Research

from universities, journals, and other organizations

Scientists construct visual of intracellular 'zip code' signaling linked to learning, memory

Date:
July 15, 2013
Source:
University of Vermont
Summary:
New research provides a rare "picture" of the activity taking place at the single molecular level: visual evidence of the mechanisms involved when a cell transports mRNA (or messenger RNA) to where a protein is needed to perform a cellular function.

Much of biomedical science -- both mystifying and awe-inspiring to the lay public -- depends on an unwavering focus on things that can't be easily seen, like the inner-workings of cells, in order to determine how and why disease develops. New research authored by Thomas Sladewski, a University of Vermont graduate student working in the laboratory of Kathleen Trybus, Ph.D., and colleagues, provides a rare "picture" of the activity taking place at the single molecular level: visual evidence of the mechanisms involved when a cell transports mRNA (or messenger RNA) to where a protein is needed to perform a cellular function.

Related Articles


The study appears in the June 30, 2013 Nature Structural and Molecular Biology.

The process of mRNA localization is critical for cellular function. When defects in mRNA transport take place, human diseases, such as spinal muscular atrophy and Alzheimer's disease, can occur. The transport of mRNAs is also important for neuronal development and synaptic plasticity, which is necessary for learning and memory.

According to Trybus, a UVM professor of molecular physiology and biophysics, ensuring proper cellular function is challenging. "The proteins responsible for orchestrating this task are not uniformly distributed, but they often need to be in a certain place at a certain time," she says. That's where mRNA plays a role; cells employ a unique identifier signal in the mRNA called a "zip code" to ensure it transports to the place where the protein is needed.

"Just like the address on a piece of mail, these zip codes help transport the mRNA by linking up with a tiny molecular motor called myosin, which walks on a track called actin, carrying the mRNA to its destination," Trybus explains.

Sladewski says that most mRNAs that are transported actually have multiple zip codes, which is like writing the address four times on a piece of mail. "In our study, one question that we asked is why these mRNAs have so many zip codes when it only needs one to be transported?" he says.

This redundancy, it turns out, is very important. "At the cellular level, recruitment of a myosin motor to a zip code relates to probability," Sladewski explains. A mRNA with one zip code has a probability of engaging with either zero or one myosin motor, but a mRNA with four zip codes will engage with between zero to four myosin motors. In this case, the multiple zip codes -- redundancy -- ensure that the mRNA will engage with at least one motor and will be successfully transported to its destination.

"You can think of this like shipping a box," says Sladewski. "We normally address only one side of a box so the carrier needs to search up to six sides of the box to find the address, but, if you put the address on each of the six sides, no matter which orientation the box is in, the mailman knows its destination without having to search for it."

To create the visual of these single molecules -- mRNPs -- moving in real time, Trybus, Sladewski and colleagues reconstructed all of the components essential to transporting mRNA in the cell and then used an imaging technology called total internal reflection microscopy (TIRF).

"mRNPs are really tiny -- approximately 1000 times smaller than the width of a human hair -- which makes them challenging to see," Sladewski says. In order to see these mRNPs moving on even smaller actin tracks, as well as distinguish the mRNP from the actin, he and the research team attach a miniscule red probe on the actin and a green probe on the mRNP. "When we mix them and image with a sensitive TIRF microscope, we see green mRNPs moving on red actin tracks with high spatial resolution in real time," he says.

"By visualizing single mRNAs being carried to their destination in a test tube, we were able to understand how mRNA is moved in the cell, including how features of the myosin motor, as well as the cargo mRNA being transported, both influence the transport properties of the motor/mRNA complex," Trybus says.

Trybus, Sladewski and colleagues' study has provided a new tool for studying mRNA localization at a molecular level, which will help advance this important field of research.


Story Source:

The above story is based on materials provided by University of Vermont. The original article was written by Jennifer Nachbur. Note: Materials may be edited for content and length.


Journal Reference:

  1. Thomas E Sladewski, Carol S Bookwalter, Myoung-Soon Hong, Kathleen M Trybus. Single-molecule reconstitution of mRNA transport by a class V myosin. Nature Structural & Molecular Biology, 2013; DOI: 10.1038/nsmb.2614

Cite This Page:

University of Vermont. "Scientists construct visual of intracellular 'zip code' signaling linked to learning, memory." ScienceDaily. ScienceDaily, 15 July 2013. <www.sciencedaily.com/releases/2013/07/130715141822.htm>.
University of Vermont. (2013, July 15). Scientists construct visual of intracellular 'zip code' signaling linked to learning, memory. ScienceDaily. Retrieved December 20, 2014 from www.sciencedaily.com/releases/2013/07/130715141822.htm
University of Vermont. "Scientists construct visual of intracellular 'zip code' signaling linked to learning, memory." ScienceDaily. www.sciencedaily.com/releases/2013/07/130715141822.htm (accessed December 20, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Saturday, December 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Best Tips to Curb Holiday Carbs

The Best Tips to Curb Holiday Carbs

Buzz60 (Dec. 19, 2014) It's hard to resist those delicious but fattening carbs we all crave during the winter months, but there are some ways to stay satisfied without consuming the extra calories. Vanessa Freeman (@VanessaFreeTV) has the details. Video provided by Buzz60
Powered by NewsLook.com
Sierra Leone Bikers Spread the Message to Fight Ebola

Sierra Leone Bikers Spread the Message to Fight Ebola

AFP (Dec. 19, 2014) More than 100 motorcyclists hit the road to spread awareness messages about Ebola. Nearly 7,000 people have now died from the virus, almost all of them in west Africa, according to the World Health Organization. Video provided by AFP
Powered by NewsLook.com
Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
The Best Protein-Filled Foods to Energize You for the New Year

The Best Protein-Filled Foods to Energize You for the New Year

Buzz60 (Dec. 19, 2014) The new year is coming and nothing will energize you more for 2015 than protein-filled foods. Fitness and nutrition expert John Basedow (@JohnBasedow) gives his favorite high protein foods that will help you build muscle, lose fat and have endless energy. Video provided by Buzz60
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