Scientists at the Max Planck Institute of Biochemistry (MPIB) in Martinsried near Munich, Germany, now discovered that the protein Hub1 of this protein family has a big effect on the synthesis of proteins: Hub1 influences the way how cells translate the information that is encoded in the genes. It even allows that one gene provides the information for two proteins and thus leads to more proteins than there are genes. This mechanism could also affect the protein repertoire of humans and hence will possibly have numerous implications for health and disease. (Nature, May 25, 2011)
Each cell possesses a large number of proteins, which steer all life functions. Each protein takes on special tasks, but these can be altered through protein modifications. Particularly fascinating cases are modifications in which the proteins are modified by chemical attachment of small proteins that belong to the ubiquitin family. Ubiquitin, which was discovered in the 1970ies, is known to work as a label for degradation: proteins marked with ubiquitin are specifically recognized by the cellular shredder, the proteasome.
In the laboratory of Stefan Jentsch at the MPIB scientists identified and studied Hub1, an unusual member of the ubiquitin family. Although Hub1 has a similar structure, it functions completely different to ubiquitin and other members of this protein family. Shravan Kumar Mishra, a postdoc in the laboratory, found that Hub1 binds tightly, but not chemically linked, to the highly conserved protein Snu66. This protein is part of a cellular machine, the spliceosome, which, by a process known as “splicing”, cuts out segments of messenger RNAs (mRNAs) and pastes the remaining parts together. As mRNA molecules transport the genetic information that is stored in the genes of the chromosomes to cellular machines (ribosomes) that translate the information into proteins, splicing can significantly alter the repertoire of proteins in cells. Mishra and colleagues now discovered that binding of Hub1 to Snu66 changes the properties of this machine in a dramatic way: in the presence of Hub1 it can act on RNAs that are otherwise not spliced. In a few cases, Hub1-modified spliceosomes can even generate two different mRNAs from one single gene. In this process, which is called “alternative splicing”, one gene thus provides the information for two different proteins.
The Hub1-mediated mechanism that the Jentsch team identified may be the oldest evolved mechanism that leads to more proteins than there are genes. Mishra and co-workers found out that the mechanism they identified is conserved from single-cellular organisms like yeast to humans. As the newly discovered mechanism is expected to influence the production of a large range of proteins also in humans, the new findings will have numerous implications for human cells in health and disease.Original Publication:
Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute
Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy