The translation of the genetic code into proteins is a vital process in any cell. Prof. Mihaela Zavolan’s team at the Biozentrum, University of Basel, has now uncovered important factors that influence the speed of protein synthesis in the cell. The results, recently published in “PNAS”, serve as a basis to better analyze translational control in a wide range of cell types.
Proteins perform various jobs in cells, they catalyze thousands of biochemical reactions, relay signals and are required for building cellular structures and transport processes. Within every single cell of our body vast quantities of proteins are produced non-stop.
The growth, differentiation and functions of cells are intimately coupled to their protein synthesis activity, which translates the genetic code into proteins. The research team led by Prof. Mihaela Zavolan at the Biozentrum, University of Basel, has investigated thousands of genes in growing yeast cells and uncovered determinants affecting the speed with which different proteins are synthesized.
Protein synthesis: From genetic code to protein
The production of proteins requires three main players: the mRNA that carries the gene’s message and works as a template; the tRNA brings the protein building blocks, the amino acids, to the ribosome; and the ribosome that chains the amino acids into the protein sequence.
In a typical eukaryotic cell, there are millions of ribosomes that assemble proteins, according to the specific needs of the cell. Lined up like string of pearls, multiple ribosomes are typically working on a given mRNA to simultaneously produce a corresponding number of proteins.
Factors that control protein translation
“We wanted to know which factors determine the synthesis rates of proteins, especially at the level of the elongation of the amino acid chain. Earlier studies suggested it is infrequently that ribosomes collide with each other, which would reduce the protein output,” says Zavolan, “but we couldn’t find evidence supporting this crash, even for mRNAs with high ribosome density.”
Furthermore, the researchers have discovered that also the charge of the incorporated amino acids is as important for the speed of elongation as the availability of tRNAs. “This is, for example, the case for the proteins of the ribosome itself. We found that the positively charged amino acids of ribosomal proteins markedly reduce the speed with which ribosomes proceed on the corresponding mRNAs,” says Zavolan.
“However, ribosomal proteins are optimized in many ways to keep a high speed of translation, for example by being encoded with codons that correspond to very abundant tRNAs.” In addition to the well-known parameters, the factors described in the study play quite a substantial role in explaining the variability in translation rates between mRNAs.
From sensitive mRNAs to disease
The scientists want to further investigate how translational control contributes to the regulation of cell fate. There are indications that certain mRNAs are more sensitive to changes in the number of ribosomes in the cell than others. One such mRNA encodes a transcription factor involved in the formation of red blood cells.
“A reduction in the number of ribosomes, caused by mutations, strongly affects this factor and impairs the maturation process of red blood cells. Therefore, the affected individuals suffer from anemia”, says Zavolan. “By extending our approach to other systems, we aim to better understand which mRNAs are especially sensitive to changes in translation.”
Prof. Dr. Mihaela Zavolan, University of Basel, Biozentrum, Tel. +41 61 207 15 77, E-Mail: email@example.com
Dr. Katrin Bühler, University of Basel, Biozentrum, Communications, tel. +41 61 207 09 74, email: firstname.lastname@example.org
Andrea Riba, Noemi Di Nanni, Nitish Mittal, Erik Arhne, Alexander Schmidt, Mihaela Zavolan. Protein synthesis rates and ribosome occupancies reveal determinants of translation elongation rates. PNAS.
PNAS (2019), doi: 10.1073/pnas.1817299116
Dr. Katrin Bühler | Universität Basel
Pinpointing Pollutants from Space
15.11.2019 | Max-Planck-Institut für Chemie
Chemists use light to build biologically active compounds
15.11.2019 | Westfälische Wilhelms-Universität Münster
The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Dresden has succeeded in using Selective Electron Beam Melting (SEBM) to...
Carbon nanotubes (CNTs) are valuable for a wide variety of applications. Made of graphene sheets rolled into tubes 10,000 times smaller than a human hair, CNTs have an exceptional strength-to-mass ratio and excellent thermal and electrical properties. These features make them ideal for a range of applications, including supercapacitors, interconnects, adhesives, particle trapping and structural color.
New research reveals even more potential for CNTs: as a coating, they can both repel and hold water in place, a useful property for applications like printing,...
If you've ever tried to put several really strong, small cube magnets right next to each other on a magnetic board, you'll know that you just can't do it. What happens is that the magnets always arrange themselves in a column sticking out vertically from the magnetic board. Moreover, it's almost impossible to join several rows of these magnets together to form a flat surface. That's because magnets are dipolar. Equal poles repel each other, with the north pole of one magnet always attaching itself to the south pole of another and vice versa. This explains why they form a column with all the magnets aligned the same way.
Now, scientists at ETH Zurich have managed to create magnetic building blocks in the shape of cubes that - for the first time ever - can be joined together to...
Quantum-based communication and computation technologies promise unprecedented applications, such as unconditionally secure communications, ultra-precise...
In two experiments performed at the free-electron laser FLASH in Hamburg a cooperation led by physicists from the Heidelberg Max Planck Institute for Nuclear physics (MPIK) demonstrated strongly-driven nonlinear interaction of ultrashort extreme-ultraviolet (XUV) laser pulses with atoms and ions. The powerful excitation of an electron pair in helium was found to compete with the ultrafast decay, which temporarily may even lead to population inversion. Resonant transitions in doubly charged neon ions were shifted in energy, and observed by XUV-XUV pump-probe transient absorption spectroscopy.
An international team led by physicists from the MPIK reports on new results for efficient two-electron excitations in helium driven by strong and ultrashort...
15.11.2019 | Event News
15.11.2019 | Event News
05.11.2019 | Event News
15.11.2019 | Power and Electrical Engineering
15.11.2019 | Power and Electrical Engineering
15.11.2019 | Ecology, The Environment and Conservation