Premiere in artificial cell division
A research team has succeeded for the first time in using DNA nanotechnology to develop an important building block for artificial cell division: a ring of DNA nanotubes that could be used in artificial cell division.
During cell division, a protein ring forms around the cell equator, which contracts to divide the cell into two daughter cells. Scientists from the Max Planck Institute for Medical Research in Heidelberg and the Center of Molecular Biology of Heidelberg University, in cooperation with researchers from Dortmund, Dresden, Tübingen and Harvard, have succeeded for the first time in synthesizing such a contractile ring with the help of DNA nanotechnology and to uncover its contraction mechanism. The results have been published in Nature Communications.
In synthetic biology, researchers try to recreate crucial mechanisms of life in vitro, such as cell division. The aim is to be able to artificially produce minimal cells that are composed of as few components as possible. A research team led by Kerstin Göpfrich from the Max Planck Institute for Medical Research and Heidelberg University has now synthetically reproduced contractile rings for cell division using polymer rings composed of DNA nanotubes.
Ring formation crucial for cell division
The formation of a ring that constricts and separates dividing cells is an important step in natural cell division. In nature, this is achieved by a machinery of proteins: motor proteins powered by chemical energy from ATP hydrolysis pull together a ring of filaments of the protein actin. Adenosine triphosphate, or ATP, is a molecule that occurs in all living cells and supplies the energy for numerous cellular processes.
New artificial alternative to natural motor proteins
The contraction mechanism of the DNA rings developed by the MPI researchers Kerstin Göpfrich, Maja Illig and Kevin Jahnke no longer relies on motor proteins powered by ATP hydrolysis. Instead, molecular attraction between ring segments can trigger the contraction of the polymer rings.
This molecular attraction can be induced in two ways: either by crosslinking molecules with two “sticky” ends that can connect two polymer segments, or through an interaction where the polymers are surrounded by molecules that press the segments together. This mechanism consumes no chemical energy, meaning that no energy source needs to be incorporated in the synthetic cell for the mechanism to function.
Completely synthetic dividing machine in view
"We are convinced that we are only at the beginning. Our new development gives us the courage to dream of a completely synthetic division machinery for synthetic cells, one that is not necessarily based on proteins," says research group leader Kerstin Göpfrich. “Proteins cannot copy themselves. Therefore, we believe that a nucleic acid-based machinery for synthetic cells may be a shortcut towards creating artificial life.” The theory and simulation that support the experiments under her leadership make it possible to explain quantitatively how the polymer rings form and contract. On this basis, it is possible to determine how the diameter of the DNA ring can be precisely controlled, which is highly significant for future applications of contractile rings in synthetic biology.
Mechanisms for cell division are an important step towards an artificial cell, the construction of which facilitates a better understanding of the functional mechanisms of natural cells and, thus, of the foundations of life.
Note: The original text of the press release comes from TU Dortmund University and has been slightly modified in this version.