New results show which proteins assist the natural recycling process in the body
Cells collect, decompose and recycle surplus or damaged cell material. This process, known as autophagy, is important, because cellular waste can be harmful to the entire organism if it accumulates in the cells. Like the treatment of household waste, autophagy requires certain mechanisms and elements.
A team led by Prof. Dr. Claudine Kraft from the Institute of Biochemistry and Molecular Biology at the University of Freiburg and Levent Bas from the Institute of Biochemistry and Cellular Biology at the University of Vienna in Austria has made new findings on the role of proteins in the amalgamation of autophagosomes and vacuoles which have now been published in the latest edition of the Journal of Cell Biology (JCB).
During the process of autophagy, damaged cellular components, unused proteins and other cellular waste are incorporated into a vesicle, called the autophagosome, rather like how domestic waste is packed up in bin bags. In mammals the vesicles are transported to a lysosome, or in yeasts and plants to vacuoles, the cell organelles.
These organelles have a similar function to a recycling plant: they decompose the materials included with the autophagosomes, so that the individual components can be reused. Numerous proteins initiate and regulate the process in the cells: more than 40 different types have already been identified.
However their molecular functions are still largely unknown. Also, until now it has not been understood how the autophagosomes fuse with vacuoles so that the cellular waste can be recycled.
In her latest publication the Freiburg biochemist offers a possible explanation: in order to understand what is needed for the fusion of the autophagosomes and vacuoles, Kraft and Bas and their team have traced the process in the laboratory. They segregated vacuoles, autophagosomes and intracellular liquid from yeast cells and created an environment in which the fusion could be observed in vitro, that is, outside a living organism.
In general, membrane fusions require four bundled proteins known as SNARE proteins. Kraft and her colleagues have now managed to confirm that the fusion of the autophagosomes and vacuoles is also a process driven by SNARE proteins and that three already-known SNAREs are operative in the fusion process.
They also discovered the fourth necessary SNARE, now called Ykt6. These results help to understand autophagy and its underlying molecular processes better. And thanks to their newly-developed in-vitro approach, in future it will be possible to identify other proteins that operate in the fusion process.
Levent Bas, Daniel Papinski, Mariya Licheva, Raffaela Torggler, Sabrina Rohringer, Martina Schuschnig, and Claudine Kraft (2018): Reconstitution reveals Ykt6 as the autophagosomal SNARE in autophagosome-vacuole fusion. In: Journal of Cell Biology. DOI: 10.1083/jcb.201804028
Prof. Dr. Claudine Kraft
Institute of Biochemistry and Molecular Biology
University of Freiburg
Rudolf-Werner Dreier | idw - Informationsdienst Wissenschaft
Interfacial engineering core@shell nanoparticles for active and selective direct H2O2 generation
19.09.2018 | Science China Press
Making better use of enzymes: a new research project at Jacobs University
19.09.2018 | Jacobs University Bremen gGmbH
Thin-film solar cells made of crystalline silicon are inexpensive and achieve efficiencies of a good 14 percent. However, they could do even better if their shiny surfaces reflected less light. A team led by Prof. Christiane Becker from the Helmholtz-Zentrum Berlin (HZB) has now patented a sophisticated new solution to this problem.
"It is not enough simply to bring more light into the cell," says Christiane Becker. Such surface structures can even ultimately reduce the efficiency by...
A study in the journal Bulletin of Marine Science describes a new, blood-red species of octocoral found in Panama. The species in the genus Thesea was discovered in the threatened low-light reef environment on Hannibal Bank, 60 kilometers off mainland Pacific Panama, by researchers at the Smithsonian Tropical Research Institute in Panama (STRI) and the Centro de Investigación en Ciencias del Mar y Limnología (CIMAR) at the University of Costa Rica.
Scientists established the new species, Thesea dalioi, by comparing its physical traits, such as branch thickness and the bright red colony color, with the...
Scientists have succeeded in observing the first long-distance transfer of information in a magnetic group of materials known as antiferromagnets.
An international team of researchers has mapped Nemo's genome, providing the research community with an invaluable resource to decode the response of fish to...
Graphene is considered a promising candidate for the nanoelectronics of the future. In theory, it should allow clock rates up to a thousand times faster than today’s silicon-based electronics. Scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) and the University of Duisburg-Essen (UDE), in cooperation with the Max Planck Institute for Polymer Research (MPI-P), have now shown for the first time that graphene can actually convert electronic signals with frequencies in the gigahertz range – which correspond to today’s clock rates – extremely efficiently into signals with several times higher frequency. The researchers present their results in the scientific journal “Nature”.
Graphene – an ultrathin material consisting of a single layer of interlinked carbon atoms – is considered a promising candidate for the nanoelectronics of the...
03.09.2018 | Event News
27.08.2018 | Event News
17.08.2018 | Event News
19.09.2018 | Life Sciences
19.09.2018 | Physics and Astronomy
19.09.2018 | Information Technology