Another puzzle of genetic research has been decoded

RNA must be transported within the cell in order to be translated at the right place. However, the motor proteins dynein and kinesin actually move in opposite directions. "We want to understand why the transport still succeeds and why the genetic material to be transported does not simply remain in place," explains Prof. Dr. Janosch Hennig, Chair of Biochemistry IV at the University of Bayreuth, who was involved in the research. Together with Dr. Simone Heber and Dr. Anne Ephrussi at the European Molecular Biology Laboratory (EBML) in Heidelberg, the mRNA, microtubule and kinesin were made visible using a special technique called single-molecule microscopy. This revealed that a specific protein, a tropomyosin isoform, becomes active and thus prevents the tug-of-war between kinesin and dynein. The researchers have also created a spatial structural model of this kinesin-tropomyosin interaction.

RNA transport in a cell: The kinesin motor proteins (pink) move along microtubules (blue) as if on "highways".

"We have taken a big step forward here," says Janosch Hennig: "We now know that tropomyosin prevents certain processes and helps to adjust the direction of mRNA transport. This means, for example, that RNA transport could be specifically switched on or off in certain cell types. This is still a dream of the future, but another step has been made."