Watch enzymes at work
Using a new method, German scientists were able to observe for the first time in living cells how genes are regulated, i.e. marked with enzymes and switched off. Since gene regulation is disrupted in serious diseases such as cancer, the researchers hope the technology will provide new insights for cancer research.
The scientists led by Lothar Schermelleh from the University of Munich and Heinrich Leonhardt from the Max Delbrück Center for Molecular Medicine in Berlin labeled so-called DNA methyltransferases with green or red fluorescent dyes. These enzymes attach methyl groups to specific sites in the DNA, thereby preventing the genes from being read.
In order to track the activity of the enzymes, the researchers inserted certain substances into the cells as "traps": As soon as a methyltransferase attached a methyl group to the DNA, the trap snapped shut and the enzyme got stuck. The researchers were able to observe the captured, glowing colored enzymes under a microscope.
Until now, the activity of DNA methyltransferases could only be observed in the test tube – but not in living cells. With their new technique, the scientists are hoping for new insights into the regulation of DNA methylation and indications of possible sources of cancer-causing errors in gene regulation.
