Cells – Live and in 3D
Living cells are highly complex entities built from thousands of different macromolecules with many unexplored areas. Proteins often form large complexes which play an important role, but they are fragile outside of the cells. Wolfgang Baumeister and his team investigate the architecture of proteins in their native environment and evaluate how they cooperate with other cell components.
In each cell, countless molecular machines work ceaselessly to keep vital processes going. These include protein factories (ribosomes) and “shredders” (proteasomes), which dispose of defective or no longer needed proteins. They consist of proteins which have joined forces in large complexes. However, before the scientists can gain insight into their function, they must identify their structure. With established research methods, this has often not been possible so far.
The research department of Wolfgang Baumeister has developed a method which opens up completely new possibilities for structural research: cryo-electron tomography (CET). The cell is “shock-frozen” to preserve its delicate structure. Next, two-dimensional electron microscopic images are taken of the object from different perspectives, out of which then a three-dimensional image is constructed.
The architecture of proteins
Using this method, Baumeister’s group has significantly contributed to the elucidation of molecular machines that are involved in protein folding and degradation. Now the scientists are focusing their interest on numerous other cell structures such as assemblies of ribosomes, pores in the cell nucleus membrane, the contact sites between nerve cells (synapses) or protein complexes in membranes and cell walls. In the future, they hope to decode all of the unexplored areas of the cell.