Cells can be thought of as cities, with factories, a transport system, and lots of building activity. An international team led by scientists at the University of Groningen studied cells growing under different conditions and measured the speed of molecule transport. They found that some conditions led to changes in the mobility inside the cells, caused by the clustering of proteins that produce the building materials for growth. It could be that clustering enables the proteins to produce those building blocks more efficiently. The research is published in the journal Molecular Cell.
The research started with a seemingly simple question. How much movement is there within a cell? “We provided bacteria with different nutrients and this resulted in different growth rates,” explains Matthias Heinemann, Professor of Molecular Systems Biology. Movement was measured by inserting tiny (40 nanometers) fluorescent particles in the cells that could be tracked under the microscope. “To our surprise, we found that particle movement under different conditions could vary by a factor of three.”
The scientific literature could not explain this observation. By analyzing the cell content, the scientists found a correlation between movement of the fluorescent particles and the number of proteins that are involved in the production of amino acids. “More of these proteins meant less movement inside the cell,” says Heinemann. “This led us to the question of why this happens. Our hypothesis was that these proteins form clusters that act as obstacles to movement inside the cells.”









