Navigation Links
Sweet! -- sugar plays key role in cell division
Date:2/5/2010

Using an elaborate sleuthing system they developed to probe how cells manage their own division, Johns Hopkins scientists have discovered that common but hard-to-see sugar switches are partly in control.

Because these previously unrecognized sugar switches are so abundant and potential targets of manipulation by drugs, the discovery of their role has implications for new treatments for a number of diseases, including cancer, the scientists say.

In the January 12 edition of Science Signaling, the team reported that it focused efforts on the apparatus that enables a human cell to split into two, a complicated biochemical machine involving hundreds of proteins. Conventional wisdom was that the job of turning these proteins on and off thus determining if, how and when a cell divides fell to phosphates, chemical compounds containing the element phosphorus, which fasten to and unfasten from proteins in a process called phosphorylation.

Instead, the Johns Hopkins scientists say, there is another layer of regulation by a process of sugar-based protein modification called O-GlcNAcylation (pronounced O-glick-NAC-alation). "This sugar-based system seems as influential and ubiquitous a cell-division signaling pathway as its phosphate counterpart and, indeed, even plays a role in regulating phosphorylation itself," says Chad Slawson, Ph.D., an author of the paper and research associate in the Department of Biological Chemistry, Johns Hopkins University School of Medicine.

Because the sugar molecule has some novel qualities it is small, easily altered, and without an electrical charge it is virtually imperceptible to researchers using standard physical techniques of detection such as mass spectrometry.

Suspecting that the sugar known as O-GlcNAc might play a role in cell division, the Hopkins team devised a protein-mapping scheme using new mass spectrometric methods. Essentially, they applied a combination of chemical modification and enrichment methods, and new fragmentation technology to proteins that comprise the cell division machinery in order to figure out and analyze their molecular makeup, identifying more than 150 sites where the sugar molecule known as O-GlcNAc was attached. Phosphates were found to be attached at more than 300 sites.

They noticed that when an O-GlcNAc molecule was located near a phosphate site, or at the same site, it prevented the phosphate from attaching. The proteins involved in cell division weren't phosphorylated and activated until O-GlcNAc detached.

"I think of phosphorylation as a micro-switch that regulates the circuitry of cell division, and O-GlcNAcylation as the safety switch that regulates the microswitches," says Gerald Hart, Ph.D., the DeLamar Professor and director of biological chemistry at the Johns Hopkins School of Medicine.

Using a standard human cell line (HeLa cells), the scientists discovered abnormalities when they disrupted the cell division process by adding extra O-GlcNAc. Although the cell's chromosome-containing nuclei divided normally, the cells themselves didn't divide, resulting in too many nuclei per cell a condition known as polyploidy that's exhibited by many cancer cells.

The researchers not only mapped O-GlcNAc and phosphorylation sites but also measured changes in the cell division machinery, because, Hart says, the chemical changes act more like "dimmer" switches, than simple on/off ones.

As important as the discovery is to a deeper understanding of cell division, Hart says, this extensive cross talk between O-GlcNAc and phosphorylation is paradigm-shifting in terms of signaling. Signaling is how a cell perceives its environment, and how it regulates its machinery in response to stimuli. The new sugar switches reveal that the cellular circuitry is much more complex than previously thought, he adds.


'/>"/>
Contact: Maryalice Yakutchik
myakutc1@jhmi.edu
443-287-2251
Johns Hopkins Medical Institutions
Source:Eurekalert

Related biology news :

1. Right breakfast bread keeps blood sugar in check all day
2. Sugary drinks, not fruit juice, may be linked to insulin
3. The accumulation of sugar in neurons may explain the origin of several neurodegenerative diseases
4. Too much sugar turns off gene that controls the effects of sex steroids
5. Too much fructose could leave dieters sugar shocked
6. Cornell researchers prove how plants transport sugars
7. Study of sugars on cell surface identifies key factor in flu infection
8. ESFs workshop restores good name of sugar
9. Sugar linkage could lead to better treatment for autoimmune diseases
10. Genetic variation linked to sugary food
11. Diabetes linked to male infertility; excess sugars in the body have direct effect on sperm quality
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/1/2016)... , Feb. 1, 2016  Wocket® smart wallet ( www.wocketwallet.com ) ... television personality, Joey Fatone . Las Vegas ... fans. --> Las Vegas , where Joey ... --> The new video ad was filmed at the Consumer Electronics ... at the Wocket booth to meet and greet fans. ...
(Date:1/22/2016)... , January 22, 2016 /PRNewswire/ ... announced the addition of the  "Global ... their offering. --> http://www.researchandmarkets.com/research/4lmf2s/global_behavioral ... the  "Global Behavioral Biometric Market 2016-2020" ... Research and Markets ( http://www.researchandmarkets.com/research/4lmf2s/global_behavioral ) ...
(Date:1/20/2016)... Jan. 20, 2016  Synaptics Incorporated (NASDAQ: ... solutions, today announced sampling of S1423, its newest ... and small screen applications including smartwatches, fitness trackers, ... round and rectangular shapes, as well as thick ... with moisture on screen, while wearing gloves, and ...
Breaking Biology News(10 mins):
(Date:2/8/2016)... ... February 08, 2016 , ... Bulk food ... bulk foods at various stages of the production process. Despite frequently inspecting loose ... bulk products post packaging such as sacks of dry powders. , Mettler-Toledo Product ...
(Date:2/8/2016)... -- NanoViricides, Inc. (NYSE MKT: NNVC) (the "Company"), a nanomedicine company developing ... MPH, will present information about the company,s programs at the BIOCEO ... New York City . --> ... 5:30PM EST. Registered attendees can request a one on one meeting ... --> New York City . ...
(Date:2/8/2016)... , Feb. 8, 2016  Diplomat Pharmacy, Inc. (NYSE: DPLO) announced today that its new website ... pharmacy resource–user-centric, story-driven, knowledge-based and mobile-friendly. Visit the ... ... ... "The goal was to ...
(Date:2/6/2016)... , ... February 06, 2016 , ... The Center for ... for middle and high school teachers on Wednesday February 10, 2016. This Bite ... the Smithsonian-Mason School of Conservation, located at 1500 Remount Road in Front Royal, VA ...
Breaking Biology Technology: