Corporate Banner
Satellite Banner
Genomics
Scientific Community
 
Become a Member | Sign in
Home>News>This Article
  News
Return

Molecular Monkey Arranges X-Chromosome Activation

Published: Friday, July 26, 2013
Last Updated: Friday, July 26, 2013
Bookmark and Share
Protein moulds RNA to ensure that activating factors can hold on to it.

X chromosomes are very special genetic material. They differ in number between men and women. To achieve equality between sexes, one out of two X chromosomes in women is silenced. In flies, the opposite happens: in male flies, the only available X chromosome is highly activated, to compensate for the absence of the second X-chromosome. Researchers from the Max Planck Institute of Immunobiology and Epigenetics (MPI-IE) in Freiburg have now shown how the RNA molecules and proteins involved in the activation find and stick to each other. Similar to a monkey that grabs a liana with hands and feet, one of the proteins holds on to the RNA. Then it moulds the molecular liana with its hands and thus generates a dynamic RNA - protein meeting place.

Just a few years ago, they were assumed to be genetic trash: DNA sequences that are not translated into proteins. But this has rapidly changed during the last years. Nowadays, it is widely known among scientists that much of the DNA is transcribed into RNA that, in turn, can act as gene regulator and structural element. Also in the regulation of sex chromosomes, RNA plays a central role. In both female humans and male flies one X chromosome is covered by a protein-RNA complex. In humans, this leads to chromosome silencing, while in flies it results in a double activation of the chromosome. Misregulation is lethal. Although known for many years, the interaction between the central proteins and the distinct role of the RNA strand was unclear.

Asifa Akhtar of the MPI-IE and her team now unravelled the function of the RNA and the interaction of the proteins. The protein MLE that is known to be a central player in X chromosome activation binds to the RNA in a very special manner. Like a monkey that grabs a liana with hands and feet, the protein grabs the RNA in two different ways. While one site is a simple anchor (the feet), the other (the hands) changes the form of the RNA. “The protein MLE moulds the RNA strand. This allows MLE to bind the RNA in a dynamic manner”, says Asifa Akhtar, head of the study. Like one monkey helping the other to catch the liana MLE could thus help other proteins to grab the RNA strand. Thus, the whole X chromosome can be covered by the RNA-protein complex.

During his PhD work, first author Ibrahim Ilik investigated why MLE was found at the same places on the X chromosome but did not directly interact with other proteins. “The biochemical and the biological results seemed to point in different directions in the beginning”, says Ilik. “But when we realised that the proteins bind highly specifically to certain regions of the very long RNA, this was a very exciting moment.”

The researchers also found that individual mutations in the RNA hardly harm the protein-RNA binding. Only multiple mutations lead to a non-functional RNA and thus to lethality of male flies. “The system is very robust for evolutionary influences. This shows how important it is for the survival of the animals.  In this, RNA could provide the necessary plasticity”, says Akhtar. The scientists now want to explore the evolutionary conservation of the RNA-protein system and its equivalent in mammals.

Scientists at the Max Planck Institute of Immunobiology and Epigenetics (MPI-IE) in Freiburg investigate the development of the immune system over the course of evolution and during lifetime. They analyse genes and molecules that are important for immune cells maturation and activation. Researchers in the field of epigenetics investigate the inheritance of traits that are not caused by changes in the DNA sequence. Epigenetic research is expected to lead to a better understanding of many complex diseases, such as cancer and metabolic disorders.


Further Information

Join For Free

Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 3,000+ scientific posters on ePosters
  • More than 4,500+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.


Scientific News
Scientists Find Evidence That Cancer Can Arise Changes
Researchers at Rockefeller University have found a mutation that affects the proteins that package DNA without changing the DNA itself can cause a rare form of cancer.
Modified Microalgae Converts Sunlight into Valuable Medicine
A special type of microalgae can soon produce valuable chemicals such as cancer treatment drugs and much more just by harnessing energy from the sun.
Gene That Lowers Heart Attack Risk Identified
Individuals with a rare twelve-letter deletion from a gene on chromosome 17 have significantly reduced non-HDL cholesterol levels and a 35% lower than average risk of heart disease.
Testing Non-Breast/Ovarian Cancer Genes
Researchers have found that expanding gene panel beyond breast/ovarian cancer genes in these patients does not add any clinical benefit. Instead, testing has produced more questions than answers.
Myeloid-Derived Suppressor Cells Play Role in Tumor Growth
Researchers at Baylor College of Medicine have reported a new mechanism that helps cancer cells engage myeloid-derived suppressor cells.
Cancer Cells Coordinate to Form Roving Clusters
Rice University scientists identify ‘smoking gun’ in metastasis of hybrid cells.
Genes For Nose Shape Found
Genes that drive the shape of human noses have been identified by a UCL-led study.
Transcription Factor Isoforms Implicated in Colon Diseases
UC Riverside study explains how distribution of two forms of a transcription factor in the colon influence risk of disease.
Drug Might Help Treat Sepsis
A DNA enzyme called Top1 plays a key role in turning on genes that cause inflammation in mouse and human cells in response to pathogens. A drug blocking this enzyme rescued mice from lethal inflammatory responses, suggesting a potential treatment for sepsis.
NIH Funds New Studies on Ethical, Legal and Social Impact of Genomic Information
Four new grants from the National Institutes of Health will support research on the ethical, legal and social questions raised by advances in genomics research and the increasing availability of genomic information.
Skyscraper Banner

SELECTBIO Market Reports
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
3,000+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
4,500+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FOR FREE!