Featured Research

from universities, journals, and other organizations

Rearranging the cell's skeleton: Small molecules at the cell’s membrane enable cell movement

Date:
February 2, 2012
Source:
Johns Hopkins Medicine
Summary:
Cell biologists have identified key steps in how certain molecules alter a cell’s skeletal shape and drive the cell’s movement.

Ruffles form on cells to help them crawl. These ruffles were formed from glowing pieces of cell skeleton.
Credit: Courtesy of the Inoue lab.

Cell biologists at Johns Hopkins have identified key steps in how certain molecules alter a cell's skeletal shape and drive the cell's movement.

Results of their research, published in the December 13 issue of Science Signaling, have implications for figuring out what triggers the metastatic spread of cancer cells and wound-healing.

"Essentially we are figuring out how cells crawl," says Takanari Inoue, Ph.D., an assistant professor of cell biology and member of the Center for Cell Dynamics in the Johns Hopkins University School of Medicine's Institute for Basic Biomedical Sciences. "With work like ours, scientists can reveal what happens when cells move when they aren't supposed to."

Their new discovery highlights the role of the cell's skeleton, or cytoskeleton, in situations where "shape shifting" can rapidly change a cell's motion and function in response to differing environmental conditions.

When cell's such as fibroblasts, which gather to heal wounds, move from one place to another, its cytoskeleton forms ripple-like waves or ruffles across its surface that move towards the front of the cell and down, helping pull the cell across a surface. Researchers have shown that these ruffles form when a small molecule, PIP2, appears on the inside surface of the membrane at the front edge of a cell. Until now, however, they have been unable to recreate cell ruffles simply by directing PIP2 to the cell's front edge. Manipulations have instead led the cytoskeleton to form completely different structures, squiggles that zip across the inside of the cell like shooting stars across the sky, which the researchers call comets.

In their experiments, Inoue and his group looked for factors that determined whether a cell forms ruffles or comets. The researchers tried to create ruffles on the cell by sending in an enzyme to the cell membrane that converts another small molecule into PIP2. Using cytoskeleton building blocks marked to glow, the team used a microscope to watch the cytoskeleton assembling itself and saw that this approach caused the cytoskeleton to form comets, not the ruffles that the researchers had predicted.

The team suspected that comets formed because of a fall in levels of another small molecule used to make PIP2, PI4P.

To test this idea, the researchers tried to make ruffles on cells only by increasing PIP2 at the membrane, rather than changing the quantities of any other molecules. Using molecular tricks that hid existing PIP2 then revealed it, the researchers effectively increased the amount of available PIP2 at the membrane. This time the researchers saw ruffles.

"Now that we've figured out this part of how cells make ruffles, we hope to continue teasing apart the mechanism of cell movement to someday understand metastasis," says Inoue. "It will be interesting to manipulate other molecules at the cell surface to see what other types of cytoskeletal conformations we can control," he says.

Tasuku Ueno and Christopher Pohlmeyer of Johns Hopkins University School of Medicine and Björn Falkenburger of the University of Washington were additional authors of the study.

This study was funded by grants from the National Institutes of Health and the Japan Society for the Promotion of Science.


Story Source:

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


Journal Reference:

  1. T. Ueno, B. H. Falkenburger, C. Pohlmeyer, T. Inoue. Triggering Actin Comets Versus Membrane Ruffles: Distinctive Effects of Phosphoinositides on Actin Reorganization. Science Signaling, 2011; 4 (203): ra87 DOI: 10.1126/scisignal.2002033

Cite This Page:

Johns Hopkins Medicine. "Rearranging the cell's skeleton: Small molecules at the cell’s membrane enable cell movement." ScienceDaily. ScienceDaily, 2 February 2012. <www.sciencedaily.com/releases/2012/02/120202092249.htm>.
Johns Hopkins Medicine. (2012, February 2). Rearranging the cell's skeleton: Small molecules at the cell’s membrane enable cell movement. ScienceDaily. Retrieved September 16, 2014 from www.sciencedaily.com/releases/2012/02/120202092249.htm
Johns Hopkins Medicine. "Rearranging the cell's skeleton: Small molecules at the cell’s membrane enable cell movement." ScienceDaily. www.sciencedaily.com/releases/2012/02/120202092249.htm (accessed September 16, 2014).

Share This



More Plants & Animals News

Tuesday, September 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) — The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

AFP (Sep. 16, 2014) — Scientists say a female colossal squid weighing an estimated 350 kilograms (770 lbs) and thought to be only the second intact specimen ever found was carrying eggs when discovered in the Antarctic. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com
Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) — Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

AFP (Sep. 16, 2014) — Since the arrival of Ebola in Ivory Coast, Ivorians have been abandoning their pets, particularly monkeys, in the fear that they may transmit the virus. Duration: 00:47 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