Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


How cells dispose of their waste

Defective proteins that are not disposed of by the body can cause diseases such as Alzheimer's or Parkinson's.

Scientists at the Max Planck Institute (MPI) of Biochemistry recently succeeded in revealing the structure of the cellular protein degradation machinery (26S proteasome) by combining different methods of structural biology.

The "regulatory particle" (in blue) detects the proteins tagged with ubiquitin and prepares them for degradation. The "core particle" (in red) breaks the proteins down into their single components. Credit: Julio Ortiz / Copyright: MPI of Biochemistry

The results of collaboration with colleagues from the University of California, San Francisco and the Swiss Federal Institute of Technology Zurich (ETH Zürich) represent an important step forward in the investigation of the 26S proteasome. The findings have now been published in Proceedings of the National Academy of Sciences.

At any given point in time, cells may contain only the proteins that are needed at exactly this moment. Otherwise, undesirable reactions can occur which could cause cancer or other diseases. Furthermore, the proteins have to be folded correctly to fulfill their tasks. Misfolded proteins can clump into aggregates, and neurodegenerative diseases such as Alzheimer's or Parkinson's may be the consequence. In order to prevent this, several mechanisms in the body regulate the number of proteins in the cell and degrade proteins if necessary.

"Cellular waste disposal" – the 26S proteasome – plays an important role in protein degradation. First, misfolded and potentially dangerous proteins are tagged with molecules called ubiquitin. The 26S proteasome detects the tagged proteins and breaks them down into small fragments, which are then recycled. Scientists in the team of Wolfgang Baumeister, head of the research department "Molecular Structural Biology" at the MPI of Biochemistry, have now been able to reveal its structure.

Many puzzle pieces lead to one structure

"The structure of the 26S proteasome changes continuously," explained Friedrich Förster, head of the research group "Modeling of Protein Complexes" at the MPI of Biochemistry. "That is why until now it could not be explained by means of traditional approaches, such as only using X-ray crystallography. We had to combine different methods to be successful." Electron microscopy and mass spectrometry helped to reveal the general structure of the 26S proteasome. X-ray crystallography provided detailed insights into specific areas of the molecule. The researchers then used computer software to integrate the different data and generate an overall picture.

Based on these results, the researchers next want to find out how the different mechanisms of protein degradation work in detail. "We have already developed a hypothesis of how exactly the 26S proteasome detects tagged proteins and processes them," said Stefan Bohn, scientist at the MPI of Biochemistry. The complete elucidation of the 26S proteasome and its underlying mechanisms could also be of medical importance: "Cellular waste disposal" is a therapeutic target for cancer und neurodegenerative diseases.

Dr. Wolfgang Baumeister | EurekAlert!
Further information:

More articles from Life Sciences:

nachricht Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München

nachricht Second research flight into zero gravity
21.10.2016 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>