Featured Research

from universities, journals, and other organizations

Experiments show hypothesis of microtubule steering accurate

Date:
January 23, 2014
Source:
Penn State
Summary:
Tiny protein motors in cells can steer microtubules in the right direction through branching nerve cell structures, according to researchers who used laboratory experiments to test a model of how these cellular information highways stay organized in living cells.

Model for maintenance of proper microtubule polarity in dendrites. Polymerizing microtubules entering junctions encounter existing static filaments. A complex consisting of end-binding protein 1 (EB1) and a kinesin molecular motor binds to the tip of the growing filament and moves along the static filament to co-align the filaments and maintain proper uniform orientation. The present work demonstrates that an EB1-kinesin complex is able to steer a growing microtubule in this manner without the requirement for any other cellular components.
Credit: William Hancock/Penn State

Tiny protein motors in cells can steer microtubules in the right direction through branching nerve cell structures, according to Penn State researchers who used laboratory experiments to test a model of how these cellular information highways stay organized in living cells.

Related Articles


"We proposed a model of how it works in vivo, in the living cell," said Melissa Rolls, associate professor of biochemistry and molecular biology. "But because of the complexity of the living cells, we couldn't tell if the model was possible."

Rolls then collaborated with William O. Hancock, professor of biomedical engineering, who was already working on the tiny kinesin motors that move materials throughout the cell, to test the model in the laboratory, in vitro.

"Kinesins are little machines that use chemical energy to generate mechanical forces sufficient to carry materials through the cell," said Hancock.

Cells produce enzymes, proteins and signaling chemicals in the center of the cell, and these materials are then moved to other cell areas by kinesin motors. Dendrites in nerves cells are very long, and motors need to transport molecules relatively long distances on microtubules that are constantly forming and dissolving within the cell. Because dendrites branch, the researchers wondered how the microtubules themselves move in the right direction.

Working with Yalei Chen, graduate student in cell and developmental biology in the Huck Institutes of the Life Sciences, the researchers found that kinesin motors can not only transport molecules along the tubules, but can redirect the ends of the tubules to enter the proper branch of the dendrite. They report their findings online in Current Biology.

In the laboratory, the researchers grew microtubules under the microscope and used protein engineering to attach a kinesin motor to EB1 -- a protein that binds to the growing end of microtubules.

"One of the reasons we thought the model might not work is that the molecule EB1 grabs the plus end of the microtubule very loosely," said Rolls. "We were unsure how something so dynamic could hold the forces, but it does."

The researchers found that it is a form of crowd sourcing -- while one molecule is only loosely bound and releases quickly, the microtubule's plus end is surrounded by hundreds of these molecules so the EB1 can guide the motor protein where to go. The kinesin motor walks along a stationary microtubule until it enters the branch.

In the laboratory, the combination EB1 and kinesin motor moved the microtubule ends far enough for redirection into branches.

The researchers state that "EB1 kinetics and mechanics are sufficient to bend microtubules for several seconds." They also suggest that "other kinesins also demonstrate this activity, suggesting this is a general mechanism for organizing and maintaining proper microtubule polarity in cells."


Story Source:

The above story is based on materials provided by Penn State. The original article was written by A'ndrea Elyse Messer. Note: Materials may be edited for content and length.


Journal Reference:

  1. Yalei Chen, MelissaM. Rolls, WilliamO. Hancock. An EB1-Kinesin Complex Is Sufficient to Steer Microtubule Growth InVitro. Current Biology, 2014; DOI: 10.1016/j.cub.2013.11.024

Cite This Page:

Penn State. "Experiments show hypothesis of microtubule steering accurate." ScienceDaily. ScienceDaily, 23 January 2014. <www.sciencedaily.com/releases/2014/01/140123125530.htm>.
Penn State. (2014, January 23). Experiments show hypothesis of microtubule steering accurate. ScienceDaily. Retrieved December 20, 2014 from www.sciencedaily.com/releases/2014/01/140123125530.htm
Penn State. "Experiments show hypothesis of microtubule steering accurate." ScienceDaily. www.sciencedaily.com/releases/2014/01/140123125530.htm (accessed December 20, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Saturday, December 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

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
Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Reuters - Light News Video Online (Dec. 19, 2014) Millions of monarch butterflies begin to descend onto Mexico as part of their annual migration south. Rough Cut (no reporter narration) Video provided by Reuters
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
Birds Might Be Better Meteorologists Than Us

Birds Might Be Better Meteorologists Than Us

Newsy (Dec. 19, 2014) A new study suggests a certain type of bird was able to sense a tornado outbreak that moved through the U.S. a day before it hit. Video provided by Newsy
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


Plants & Animals

Earth & Climate

Fossils & Ruins

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