Sugarcoating fruit fly development

May 29, 2009

Proteins are the executive agents that carry out all processes in a cell. Their activity is controlled and modified with the help of small chemical tags that can be dynamically added to and removed from the protein. 25 years after its first discovery, researchers at the European Molecular Biology Laboratory (EMBL) in Heidelberg have now gained insight into the role of one of these tags, a small sugar residue, that is found on many different proteins across species. In the current online issue of Science they report that the addition of this sugar tag to proteins in the nucleus of a cell is vital for normal development in fruit flies.

Over 25 years ago scientists discovered that many proteins in the and have a small sugar molecule, called GlcNAc, attached to them. The enzyme that adds this sugar is called Ogt but since its discovery it has remained elusive why attaching GlcNAc to proteins is important. Researchers in the group of Jürg Müller at EMBL have now discovered that flies lacking Ogt show dramatic developmental defects. In the absence of Ogt cells do not develop into the appropriate cell types and body segments do not differentiate according to plan.

"Expressing the right genes at the right time is critical for a developing organism," says Jürg Müller. "It is the appropriate combination of genes that tells a cell to turn into muscle, nerve or skin. This is why a tight control system regulates throughout development."

One important component of this control system is a group of regulatory proteins, called Polycomb proteins. They switch off developmental genes when and where their activity is not needed and thereby prevent the formation of specialised tissues and organs in the wrong places.

The scientists found that in the absence of Ogt, Polycomb proteins are no longer able to inactivate developmental genes. They showed that one specific Polycomb protein, called Polyhomeotic, is modified with the sugar tag by Ogt and might be the link between Ogt and development. Further investigations are necessary to find out how the sugar tag affects the function of Polyhomeotic.

"Our findings were very surprising. GlcNAc has been found on so many different proteins in mammalian cells that we expected many processes to go wrong in a fly lacking Ogt. Instead we see a very specific effect on development in that is likely brought about by a single nuclear protein that needs the sugar tag to function properly," says Maria Cristina Gambetta, who carried out the research in Müller's lab.

Source: European Molecular Biology Laboratory (news : web)

Explore further: Mycologist promotes agarikon as a possibility to counter growing antibiotic resistance

add to favorites email to friend print save as pdf

Related Stories

Study: Sugar helps control cell division

Sep 21, 2005

Johns Hopkins scientists in Baltimore say they've discovered a deceptively simple sugar is really a critical regulator of cells' natural life cycle.

A switch between life and death

Aug 28, 2006

Cells in an embryo divide at an amazing rate to build a whole body, but this growth needs to be controlled. Otherwise the result may be defects in embryonic development or cancer in adults. Controlling growth requires that ...

How nature tinkers with the cellular clock

Sep 27, 2006

The life of a cell is all about growing and dividing at the right time. That is why the cell cycle is one of the most tightly regulated cellular processes. A control system with several layers adjusts when key components ...

Recommended for you

YEATS protein potential therapeutic target for cancer

Oct 23, 2014

Federal Express and UPS are no match for the human body when it comes to distribution. There exists in cancer biology an impressive packaging and delivery system that influences whether your body will develop cancer or not.

Precise and programmable biological circuits

Oct 23, 2014

A team led by ETH professor Yaakov Benenson has developed several new components for biological circuits. These components are key building blocks for constructing precisely functioning and programmable bio-computers.

User comments : 0