Over the past few years, covalent modifications of histone tails have emerged as an important mechanism of gene regulation in eukaryotes. Now, scientists have identified a major euchromatic histone methyltransferase in mammalian cells that is crucial for normal embryonic development, and possibly the prevention of cancer. In a report published in Genes & Development, Dr. Yoichi Shinkai and colleagues have identified a protein called G9a as an enzyme that adds a methyl group to the lysine 9 amino acid residue on the histone H3 proteins that are associated with euchromatic (transcriptionally active) DNA in the mammalian genome. The researchers genetically engineered live mice and murine stem cells to lack G9a in order to determine the function of the protein.
G9a-deficient mice died between embryonic day 9.5 and 12.5, and displayed severe developmental growth retardation. In fact, the G9a-deficient mouse embryos did not appear to develop beyond embryonic day 8.5. The researchers determined that this developmental growth arrest is due, at least in part, to aberrant ly high levels of programmed cell death during embryogenesis.
G9a-deficient stem cells displayed a marked decrease in histone H3 lysine 9 methylation, and were unable to differentiate into embryonic cell types in culture. Taken together, the in vivo and in vitro evidence suggests that G9a-mediated histone H3 lysine 9 methylation serves to regulate the expression of crucial genes during development.
Dr. Shinkai and colleagues found that one of the genes regulated by G9a-mediated methylation is Mage-2a, which encodes a tumor-specific protein whose function is currently unknown. The researchers show that Mage-2a expression is induced in G9a-deficient cells, and, as Dr. Shinkai points out, "This may suggest that deregulation of histone H3 lysine 9 methylation is involved in some type of tumorigenesis."
Further delineation of other G9a target genes will elucidate the full physiological role of euchromatic G9a-mediated histone H3 lysine 9 methylation, but as this work by Dr. Shinkai and colleagues shows, the role of G9a in development is already proving to be an important one.
Heather Cosel | EurekAlert
At last, butterflies get a bigger, better evolutionary tree
16.02.2018 | Florida Museum of Natural History
New treatment strategies for chronic kidney disease from the animal kingdom
16.02.2018 | Veterinärmedizinische Universität Wien
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).
Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
16.02.2018 | Information Technology
16.02.2018 | Health and Medicine
16.02.2018 | Physics and Astronomy