Dr. Thomas P. Zwaka, associate professor in the Stem Cells and Regenerative Medicine (STaR) Center at BCM and others in his laboratory first identified Ronin and its role in maintaining stem cells in their undifferentiated state. Now he and his colleagues from the University of Houston, The University of Texas MD Anderson Cancer Center and Massachusetts Institute of Technology (MIT) in Cambridge, Mass., have identified the tiny strand of DNA that enables the protein with its co-regulator Hcf-1 to maintain the rapid growth that characterizes embryonic stems cells.
Finding this small DNA strand required determining the genetic sequence of the site to which Ronin binds in the genome, he said. They used high tech, extremely rapid sequencing methods (high throughput, massively parallel sequencing) to identify the appropriate sequences and determine their genetic code. They analyzed 866 potential binding sites and found a similar motif in 844.
As chance would have it, this genetic sequence had been previously identified in a pure bioinformatics study of genetic sequences that are present in most mammalian species. Because such sequences are conserved throughout evolution, they are believed to play a fundamental role in cellular processes. In a list of 100 most conserved genetic regions, this DNA sequence ranked fourth in frequency. In this case, researchers believe that the small DNA strand bound to a transcription factor that they had not identified. (A transcription factor governs translation of the DNA message in a gene into RNA, which can then be used by the cell's machinery as a template for a protein.)
"Ronin is that factor," said Zwaka. "Ronin binds to the 'hyperconserved enhancer element' sequence and then recruits Hcf-1. Only if it recruits Hcf-1 do we get activation of the special gene growth program."
With this highly conserved enhancer element, the Ronin/Hcf-1 combination controls a specific growth program of genes that are required in the early formation of an embryo, stem cells and maybe in some tumor cells, he said.
"When you look at the target genes of Ronin/Hcf-1, all are in the category of protein metabolism," he said.
Embryonic stem cells are characterized by rapid growth and renewal.
"Graduate students complain that they have to split and feed the cells every day. If you don't supply them with fresh medium, they die because they use it all up. It is important to understand what underlies this prolific growth," he said.
Understanding that could help scientists growth the cells better in the laboratory. Cancer growth, in many ways, simulates that of embryonic stem cells, he said. Understanding the growth program made up of 1,000 or more genes regulated by Ronin/Hcf-1 could help determine new strategies for fighting tumors.
Others who took part in this research include Dr. Marion Dejosez of BCM, Dr. Stuart S. Levine, Garrett M. Frampton, Warren Whyte and Dr. Richard A. Young of MIT, Sabrina A. Stratton and Dr. Michelle C. Barton of MD Anderson and Dr. Preethi H. Gunaratne of UH.
Funding for this work came from the National Institutes of Health, the Diana Helis Henry Medical Research Foundation and the Huffington Foundation.
When the embargo lifts, this report will be available at http://genesdev.cshlp.org/.
For more information on basic science research at Baylor College of Medicine, go to www.bcm.edu/fromthelab or www.bcm.edu/news.
Glenna Picton | EurekAlert!
Transport of molecular motors into cilia
28.03.2017 | Aarhus University
Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
28.03.2017 | Life Sciences
28.03.2017 | Information Technology
28.03.2017 | Physics and Astronomy