In a similar way, a cellular waste management system constantly picks up superfluous proteins and damaged organelles in human cells and delivers them to recycling facilities. However, if the cellular waste management system stops working, severe illnesses like Alzheimer´s disease or cancer may develop.
The picture shows the structure of the autophagic scaffold. The scientists used atomic force microscopy to visualize the hight profile of the scaffold on artificial membranes. The protein meshwork rises gradually (yellow-red) from the ground level of the membrane (black) to the crest of the scaffold (white) where it reaches its maximum hight. The resulting two-dimensional map was then projected onto a sphere which represents the autophagosome.
Picture: Thomas Wollert
Copyright: MPI of Biochemistry
Scientists at the Max Planck Institute of Biochemistry in Martinsried near Munich, Germany, recently revealed how a major cellular recycling system – autophagy – works. The results of the study have now been published in the research journal Cell.
The autophagic system in cells captures cellular waste and delivers it to specialized recycling facilities, called lysosomes. Thus autophagy protects the cell from accumulating cell debris. If autophagy slows down or stops working, severe diseases like cancer, Parkinson´s or Alzheimer´s disease may occur.
Much in the same way as trash bags envelop waste, a membrane engulfs cellular debris during autophagy. This molecular “recycling bag” is called autophagosome. After the membrane has been wrapped around the waste, it is transported to lysosomes for degradation. Because lysosomes are also surrounded by membranes, autophagosomes are able to fuse with them to deliver their content without leakage. Finally, an armada of different enzymes degrades the lysosomal content into its basic molecular building blocks.
Cellular waste differs enormously in size and shape, imposing a major challenge for the autophagic system. On the one hand the membrane of autophagosomes needs to be flexible enough to engulf the waste. On the other hand, mechanical stability is needed to guide the membrane around the waste in a zipper-like fashion. Thomas Wollert and his Research Group “Molecular Membrane and Organelle Biology” now revealed the molecular architecture of an autophagic membrane scaffold, which mechanically supports autophagosomes.Small meshes – large effects
Furthermore, the researchers were able to recreate the scaffold on artificial membranes in the test tube and to follow its assembly and disassembly in real time. “It is important that we understand the molecular mechanisms that drive autophagy to be able to modulate its speed”, said Thomas Wollert, MPIB group leader who supervised the study. “If we were able to accelerate autophagy, Alzheimer´s disease and other neurological disorders could perhaps be cured in the future.” [VS]Original Publication:
Anja Konschak | Max-Planck-Institut
Modern genetic sequencing tools give clearer picture of how corals are related
17.08.2017 | University of Washington
The irresistible fragrance of dying vinegar flies
16.08.2017 | Max-Planck-Institut für chemische Ökologie
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
17.08.2017 | Physics and Astronomy
17.08.2017 | Earth Sciences
17.08.2017 | Physics and Astronomy