Recently
scientists at the Max Panck Institute of Biochemistry in Martinsried have
discovered a way to visualize proteasomes in intact nerve cells. Proteasomes
are enzymes that are responsible for degrading damaged or unnecessary proteins, thereby allowing the cell to function properly.
Before this study, proteasomes had only
been observed in a test tube, but Wolfgang Baumeister and his team were able to
structurally characterize these proteins in healthy cells by using electron
cryo-tomography. This technique works by quickly cooling the cells to -170
degrees Celsius and then taking many pictures inside the cell. These images are
then put together to form a three-dimensional image. Through this technique
they observed that the proteasomes have a cap-like structure with regulatory
particles on either end. These ends undergo a conformational change when bound
to proteins that are soon to be degraded. They were able to characterize these
different conformational states. Their technique also discovered that only
about 25% of proteasomes actively degrade proteins.
In the
future, Wolfgang Baumeister and his team would like to observe proteasomes in
cells of people with neurodegenerative diseases like Alzheimer’s, Parkinson’s,
or Huntington’s. These diseases are often caused by damaged proteins that clump
together in the brain. By observing proteins in these types of cells, they may
be able to make important discoveries to better understand such diseases.
Max Planck Institute of Biochemistry. "Live broadcast from inside the nerve cell." ScienceDaily. ScienceDaily, 23 January 2015. .
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