Featured Research

from universities, journals, and other organizations

Atomic model of tropomyosin bound to actin

Date:
February 16, 2011
Source:
Cell Press
Summary:
New research sheds light on the interaction between the semi-flexible protein tropomyosin and actin thin filaments. The study provides the first detailed atomic model of tropomyosin bound to actin and significantly advances the understanding of the dynamic relationship between these key cellular proteins.

New research sheds light on the interaction between the semi-flexible protein tropomyosin and actin thin filaments. The study, published by Cell Press on Feb. 15th in the Biophysical Journal, provides the first detailed atomic model of tropomyosin bound to actin and significantly advances the understanding of the dynamic relationship between these key cellular proteins.

Tropomyosin is a long protein that associates with actin, a highly conserved thin filament protein found in organisms from yeast to humans. Actin, a major part of the cell's cytoskeleton, drives shape changes and cellular locomotion in many types of cells, and is part of the contractile apparatus in muscle cells. Tropomyosin binds to actin ad acts as a molecular barrier, essentially covering up active sites that are required for actin to interact with other proteins. In turn cellular signals can trigger additional regulatory proteins to move tropomyosin, dislodging the barrier in order to allow actin to associate with remodeling and motor proteins.

"Previous studies examining tropomyosin in isolation suggested that it is a coiled coil that matches the shape of actin filaments and is arranged along their surface," explains senior study author, Dr. William Lehman from the Department of Physiology and Biophysics at Boston University School of Medicine. "However, a complete elucidation of tropomyosin-based regulatory mechanisms requires a complete representation of the atomic structure and mechanical properties of the tropomyosin molecule linked to its biological substrate."

Building on previous findings that the association between tropomyosin and actin is an electrostatic attraction between oppositely charged amino acids, Dr. Lehman and colleagues explored thousands of combinations of different rotations and positions of tropomyosin to find the most favorable interaction between tropomyosin and actin. The researchers then used electron microscopy as a second approach to also reconstruct the interaction. The two methods yielded virtually identical solutions, "which is very gratifying," says Dr. Lehman.

The authors discuss how the interaction between tropomyosin and actin is just weak enough that tropomyosin can be readily perturbed by regulatory proteins and act as a molecular switch to regulate actin interaction with other proteins. "The atomic model that we propose can serve as a reference location to characterize tropomyosin regulatory movements on actin thin filaments," concludes Dr. Lehman. "Moreover, the map of actin-tropomyosin provides a structural platform to assess mutations that influence actin-tropomyosin behavior and also to develop tropomyosin-mimicking peptide drugs designed to modulate actin-myosin or other interactions."


Story Source:

The above story is based on materials provided by Cell Press. Note: Materials may be edited for content and length.


Journal Reference:

  1. Xiaochuan Edward Li, Larry S. Tobacman, Ji Young Mun, Roger Craig, Stefan Fischer, William Lehman. Atomic Model of F-Actin-Tropomyosin. Biophysical Journal, 2011; 100 (3): 586a DOI: 10.1016/j.bpj.2010.12.3385

Cite This Page:

Cell Press. "Atomic model of tropomyosin bound to actin." ScienceDaily. ScienceDaily, 16 February 2011. <www.sciencedaily.com/releases/2011/02/110215123539.htm>.
Cell Press. (2011, February 16). Atomic model of tropomyosin bound to actin. ScienceDaily. Retrieved September 22, 2014 from www.sciencedaily.com/releases/2011/02/110215123539.htm
Cell Press. "Atomic model of tropomyosin bound to actin." ScienceDaily. www.sciencedaily.com/releases/2011/02/110215123539.htm (accessed September 22, 2014).

Share This



More Plants & Animals News

Monday, September 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Cat Lovers Flock to Los Angeles

Cat Lovers Flock to Los Angeles

AFP (Sep. 22, 2014) The best funny internet cat videos are honoured at LA's Feline Film Festival. Duration: 00:56 Video provided by AFP
Powered by NewsLook.com
Washed-Up 'Alien Hairballs' Are Actually Algae

Washed-Up 'Alien Hairballs' Are Actually Algae

Newsy (Sep. 22, 2014) Green balls of algae washed up on Sydney, Australia's Dee Why Beach. Video provided by Newsy
Powered by NewsLook.com
Raw: San Diego Zoo Welcomes Cheetah Cubs

Raw: San Diego Zoo Welcomes Cheetah Cubs

AP (Sep. 20, 2014) The San Diego Zoo has welcomed two Cheetah cubs to its Safari Park. The nearly three-week-old female cubs are being hand fed and are receiving around the clock care. (Sept. 20) Video provided by AP
Powered by NewsLook.com
Chocolate Museum Opens in Brussels

Chocolate Museum Opens in Brussels

AFP (Sep. 19, 2014) Considered a "national heritage" in Belgium, chocolate now has a new museum in Brussels. In a former chocolate factory, visitors to the permanent exhibition spaces, workshops and tastings can discover derivatives of the cocoa bean. Duration: 01:00 Video provided by AFP
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:
from the past week

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