Biologists at UC San Diego have found the “missing link” in the chemical system that enables animal cells to produce ribosomes—the thousands of protein “factories” contained within each cell that manufacture all of the proteins needed to build tissue and sustain life.
Their discovery, detailed in the June 23 issue of the journal Genes & Development, will not only force a revision of basic textbooks on molecular biology, but also provide scientists with a better understanding of how to limit uncontrolled cell growth, such as cancer, that might be regulated by controlling the output of ribosomes.
Ribosomes are responsible for the production of the wide variety of proteins that include enzymes; structural molecules, such as hair, skin and bones; hormones like insulin; and components of our immune system such as antibodies.
Regarded as life’s most important molecular machine, ribosomes have been intensively studied by scientists (the 2009 Nobel Prize in Chemistry, for example, was awarded for studies of its structure and function). But until now researchers had not uncovered all of the details of how the proteins that are used to construct ribosomes are themselves produced.
In multicellular animals such as humans, ribosomes are made up of about 80 different proteins (humans have 79 while some other animals have a slightly different number) as well as four different kinds of RNA molecules. In 1969, scientists discovered that the synthesis of the ribosomal RNAs is carried out by specialized systems using two key enzymes: RNA polymerase I and RNA polymerase III. But until now, scientists were unsure if a complementary system was also responsible for the production of the 80 proteins that make up the ribosome.
That’s essentially what the UC San Diego researchers headed by Jim Kadonaga, a professor of biology, set out to examine. What they found was the missing link—the specialized system that allows ribosomal proteins themselves to be synthesized by the cell.
“We found that ribosomal proteins are synthesized via a novel regulatory system with the enzyme RNA polymerase II and a factor termed TRF2,” Kadonaga says. “For the production of most proteins, RNA polymerase II functions with a factor termed TBP, but for the synthesis of ribosomal proteins, it uses TRF2.”
“The discovery of this specialized TRF2-based system for ribosome biogenesis,” he adds, “provides a new avenue for the study of ribosomes and its control of cell growth, and should lead to a better understanding and potential treatment of diseases such as cancer.”
Other authors of the paper were UC San Diego biologists Yuan-Liang Wang, Sascha Duttke and George Kassavetis, and Kai Chen, Jeff Johnston, and Julia Zeitlinger of the Stowers Institute for Medical Research in Kansas City, Missouri. Their research was supported by two grants from the National Institutes of Health (1DP2OD004561-01 and R01 GM041249).
Kim McDonald | Eurek Alert!
Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz
Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences