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Less Is More: A Minimal Approach to Synthetic Cell Constriction

Research

Researchers at the Max Planck Institute for Biochemistry in Germany, in collaboration with a Spanish team from the CIB Margarita Salas (CSIC), have made a significant step forward in synthetic cell division. Focusing on constriction—a crucial step preceding the splitting of the cell—they drew inspiration from the process observed in E. coli bacteria to develop and optimise a minimal system capable of inducing the constriction of synthetic vesicles.

Cell division: a crucial process for life on Earth

Cells are, by definition, the smallest units of life on Earth and can only be generated by the division of an existing cell. Therefore, to continue to exist and adapt to a constantly changing environment, cells need to divide.

“In our group, we use simple biological building blocks to recreate key features of life, with a focus on cell division,” explained Aleksandra Šakanović, a postdoctoral researcher in Petra Schwille’s research group at the Max Planck Institute for Biochemistry in Martinsried, Germany. “Once formed, life can only continue to exist through cell division.”

A group of people sitting and standing in front of an outdoor swimming pool on a warm, sunny day. They are smiling for the camera. In the background, there is what might be a castle, a few trees and a small hill in the distance.
The Schwille group. In the second row, on the left, stands Petra Schwille. In the same row, side by side, are Anastasija Panevska and Aleksandra Šakanović

“For a single cell, division is the only way to reproduce; for multicellular organisms like us, cell division allows a single cell to multiply and develop into a complex organism, and it plays an important role in various processes such as tissue repair and cellular replacement.”

Division is crucial not only for the maintenance of life but also for its evolution. “During cell division, genetic information is passed on to the next generation, and mutations, and consequently adaptations, may occur.”

The Schwille group aims to understand how life works and what the smallest possible form of life might be. To this end, the group is seeking to develop a synthetic cell from scratch, a minimal system capable of dividing autonomously and passing on genetic information to the next generation.

“Synthetic cell division is what separates a static cell-size compartment from a more autonomous and life-like system,” Šakanović said.

The FtsZ system: a contender for enabling synthetic constriction

The process of cell division can be divided into three main stages. First, the cell replicates and amplifies its genetic material (DNA), then the copies of DNA are separated at the two poles of the cell. Finally, the cell constricts in the middle, adopting a dumbbell shape, before splitting and forming two new daughter cells.

In E. coli bacteria, division is driven by a highly dynamic multiprotein complex called the ‘divisome’. The divisome is composed of more than 20 proteins, but the core protein is FtsZ, which orchestrates a ring-shaped structure at the future site of division. FtsZ forms filaments that constantly assemble and disassemble. Together, these filaments create a dynamic division ring in the middle of the cell and produce a directional circumferential movement that induces cell constriction.

A mosaic of four microscopic images in black and green. The two images on the left show wavy green patterns. The top right image shows a sphere made up of green dots. The bottom right image shows a green, ellipsoidal ring.
On supported lipid bilayers, FtsZ filaments self-organise into dynamic, curved vortices. The addition of cytoFtsN in molar excess triggers a structural transition from circular patterns to more aligned and straightened bundles (left panels, scale bar: 5 µm). When encapsulated within giant vesicles in the absence of cytoFtsN, FtsZ organises into mini-rings, too small to encircle the vesicle. The presence of excess cytoFtsN facilitates the assembly of a single, fully closed ring matching the GUV diameter (right panels, scale bar: 10 µm). Once established, this ring supports progressive constriction of the giant lipid vesicle, leading to marked deformation. Source: Panevska, A., Šakanović, A., Paccione, G. et al. Optimizing spatial organization of FtsZ rings for large-scale constriction in synthetic cells. Nat Commun 17, 2320 (2026)

Increasing the size of the FtsZ ring in giant unilamellar vesicles

Several research groups have attempted to form an FtsZ ring inside giant unilamellar vesicles (GUVs), which are around ten times larger than E. coli. To increase the size of the ring, the researchers had to add various other components, such as so-called ‘molecular crowders’ and/or other divisome proteins.

But enriching the FtsZ system has its drawbacks. “When you add components to a system, it becomes biologically richer but, at the same time, more complex experimentally, with an increased risk that these components won’t work under optimal conditions,” Šakanović said. The main drawback was the absence of profound mid-cell constriction. “Without crowders, you don’t get a ring that’s big enough, but with them, you don’t get the constriction”, commented Anastasija Panevska, also a postdoctoral researcher in the Schwille group.

These limitations prompted researchers Šakanović, Panevska, and Schwille to develop a minimal system for inducing constriction that excludes crowders.

Less is more

In collaboration with German Rivas’s research group from the CIB Margarita Salas (CSIC), they demonstrated that it was possible to form a bigger FtsZ ring and induce GUV constriction whilst using only a minimal set of components. Their findings were published in Nature Communications in March 2026.

“This work is the result of a long process of discussions and optimisations,” Panevska explained. “We have identified a small peptide, cytoFtsN, which influences and regulates the self-organisation of the FtsZ filament network. It enables progressive constriction by changing the architecture and slowing down the polymerisation/depolymerisation dynamics of the filaments.”

Progressive deformation of a lipid vesicle into an asymmetric dumbbell shape.
At the onset of the time-lapse, FtsZ organises into a distinct, well-defined single ring at the future constriction site. The movie illustrates the progressive deformation of the vesicle over 322 minutes, driven by the coordinated contractile action of the FtsZ/cytoFtsN complex. Source: Panevska, A., Šakanović, A., Paccione, G. et al. Optimizing spatial organization of FtsZ rings for large-scale constriction in synthetic cells. Nat Commun 17, 2320 (2026)

Next steps

“Our goal is to achieve complete cell division,” Šakanović said. “Before that, we want to study the characteristics of our system to better understand how FtsZ and cytoFtsN interact. We also want to further improve the system.”

The Schwille group is also collaborating with Bert Poolman’s group at the University of Groningen, the Netherlands. Their MetaDivide project, funded by an ERC Advanced Grant, aims to combine synthetic cell division with another essential feature of life: metabolism. Bringing these two processes together represents an important step toward the development of synthetic cells that can divide autonomously.

As for Anastasija Panevska, she has recently secured a permanent position at the University of Ljubljana in Slovenia, where she will continue her research using model systems, focusing on pore-forming proteins. Through her research and teaching, she will help inspire the next generation of scientists, an achievement she credits to Petra Schwille.

“Petra has been a true source of inspiration for both Aleksandra and me. As a woman in science, seeing her really helped us. She provided us with a great environment and incredible support to develop our creativity and our ideas. She gave us strength and encouraged us to think outside the box. It was only when I started listening to her that it really paid off.”

Scientific publication:

Optimizing spatial organization of FtsZ rings for large-scale constriction in synthetic cells
Anastasija Panevska, Aleksandra Šakanović, Gianfranco Paccione, Germán Rivas and Petra Schwille
Nature Communications, volume 17, Article number: 2320 (2026)