Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sweet proteins do better - Max Planck researchers uncover a new function of protein modifications

03.12.2014

Many proteins in our cells are decorated with sugar molecule add-ons, which are essential for the functions of these proteins. One particular type of sugar modification, called GlcNAc, is of key importance, because our cells cannot survive without it.

Researchers at the Max Planck Institute of Biochemistry in Martinsried near Munich have recently uncovered a previously unknown mechanism explaining how this sugar residue affects protein function and thereby influences our development. These results have been published in the journal Developmental Cell.


In wild-type Drosophila embryos, the Polyhomeotic (Ph) protein is O-GlcNAcylated (pink diamonds), which is necessary to repress its target genes (no black staining).

Picture: Maria Gambetta / Copyright: MPI of Biochemistry

Proteins are responsible for all vital processes in the cells of our body. However, they are not alone: tiny sugar molecules are decorating many proteins and they often are important to make them work properly. One particular type of sugar modification, called O-linked N-acetylglucosamine - in short called O-GlcNAc - seems to be of fundamental importance, because our cells cannot survive without it.

Yet why exactly human cells die if their proteins lack the O-GlcNAc tag remains a mystery. Jürg Müller and Maria Cristina Gambetta at the Max Planck Institute of Biochemistry in Martinsried near Munich recently have addressed this question and set out to identify substrate proteins whose modification by O-GlcNAc is essential for biological processes. For their experiments the researchers made use of the less complex model organism Drosophila, also known as the fruit fly.

The researchers found that flies lacking O-GlcNAc show serious defects during their development: their cells fail to ‘remember’, which part of the body they were supposed to form. “Interestingly, we also observed the very same defects in flies lacking any member of the so-called Polycomb group of proteins” explains Maria Cristina Gambetta, the first author of the study.

The Polycomb proteins permit cells to remember their fate by specifically silencing genes, which are not needed in those cells. However, how did these two results fit together? Why are the consequences of missing O-GlcNAc so similar to the consequences of missing Polycomb proteins?

The researchers were able to show that the function of one specific Polycomb protein, called Polyhomeotic - in short Ph - only functions properly if it carries the O-GlcNAc tag. The researchers found that the O-GlcNAc tag is critical to prevent Ph from forming large macromolecular clumps, which would interfere with its ability to silence its target genes.

“This constitutes a previously unappreciated biochemical function of O-GlcNAc, namely to prevent the aggregation of a protein under normal physiological conditions”, explains Jürg Müller. “Moreover, we have been able to show that Polycomb repression is the most critical cellular process in flies that relies on O-GlcNAc.”

But how do these findings help us to advance our understanding of why our human cells need O-GlcNAc? In the latest study the researchers found out that fly and human Ph show high similarity. Consequently, also the human protein required O-GlcNAc in order to not clump together with other Ph proteins. “It will be interesting to further investigate, whether defective silencing of Polycomb target genes is also a major biological process that goes awry in human cells lacking O-GlcNAc”, Gambetta sets the agenda for the upcoming experiments. The results have recently been published in the journal Developmental Cell.
[HS]

Original Publication:
M.C. Gambetta and J. Müller: O-GlcNAcylation Prevents Aggregation of the Polycomb Group Repressor Polyhomeotic. Developmental Cell, November 26, 2014.
DOI:10.1016/j.devcel.2014.10.020

Contact:
Dr. Jürg Müller
Laboratory of Chromatin Biology
Max Planck Institute of Biochemistry
Am Klopferspitz 18
82152 Martinsried
E-Mail: muellerj@biochem.mpg.de
http://www.biochem.mpg.de/mueller

Anja Konschak
Public Relations
Max Planck Institute of Biochemistry
Am Klopferspitz 18
82152 Martinsried
Phone: +49 (0) 89 8578-2824
E-Mail: konschak@biochem.mpg.de
http://www.biochem.mpg.de


Weitere Informationen:

http://www.biochem.mpg.de/4876634/058_mueller_glcnac  - Link to the press release
http://www.biochem.mpg.de/mueller  - Research group "Chromatin Biology"
http://www.biochem.mpg.de/news  - More press releases of the MPI of Biochemistry

Anja Konschak | Max-Planck-Institut für Biochemie

More articles from Life Sciences:

nachricht Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY

nachricht NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>