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Anna-Katharina Pfitzner – Seeking fundamental answers

Prix Schläfli 2022 in Biology

Prix Schläfli 2022: Small biological building blocks are her thing: biologist Anna-Katharina Pfitzner has researched a mechanism that is key to many processes in cell biology.

Prix Schläfli 2022: Anna-Katharina Pfitzner
Image: Anna-Katharina Pfitzner

Astrid Tomczak-Plewka

Some people cannot escape their heritage. In the case of Anna-Katharina Pfitzner, this is no bad thing. The 29-year-old got to listen in on her parents' discussions regarding proteins – a hot topic of conversation between two biologists – at the family dinner table as a child. Anna-Katharina's interest in molecules, DNA and cell replication was therefore instilled in her from the cradle up, so to speak – and though she went through some "rebellious phases" as a teenager, as she says, she nevertheless followed in her parents' footsteps and completed a degree in biochemistry in Tübingen.

For her dissertation at the University of Geneva, she studied the so-called ESCRT-III machinery, which is critical to many processes in cell biology – such as repairing cell membranes or forming vesicles, which are cell compartments within the cell that transport substances. Her work involved the close study of six proteins in order to establish how ESCRT-III proteins accomplish these processes. This is a very sophisticated procedure: "With such a vast quantity of proteins, the number of configurable parameters is extremely great and requires appropriate coordination of the concentration levels for the individual sub-units and salts," as her doctoral supervisor Aurélien Roux emphasises. The ESCRT-III proteins form strands, or so-called filaments. The junior researcher has discovered that a sequence of slightly variable ESCRT-III proteins form filaments that continuously change. This in turn drives membrane deformation and splitting. "This mechanism is easy to verify and modulate, and it explains how ESCRT-III adapts to the numerous cellular functions that it performs," says Anna-Katharina Pfitzner.

"I am passionate about fundamental research"

In her view, having her work recognised with the Prix Schläfli is "a great honour. Mine is quite a niche subject." This award is not least also a recognition of fundamental research. "I am passionate about this," says Anna-Katharina Pfitzner. "We have to understand how these natural processes work in order to solve problems." To illustrate this, she takes an everyday example: "If my car suddenly breaks down, a mechanic can, of course, take apart the entire engine to find a defective part," she says. "But it is certainly very helpful to have a blueprint."

Ultimately, it is about nothing less than understanding the big picture. "When you get down to it, everything consists of chemical reactions, of atoms that react to one another according to fundamental principles." Voilà: this is the formula of life according to Anna-Katharina Pfitzner. At one point in the conversation, she expresses this sentiment with a quote by Johann Wolfgang von Goethe: "detect[ing] the inmost force which binds the world." Such sentences may seem to be expressed quite casually, yet the 29-year-old cell biologist considers very carefully what she says and how she says it. During the conversation, she sits in an unadorned room in Boston, Massachusetts, where she took up a post-doc position at Harvard Medical School in February. Her clinical surroundings seem like a reflection of her mind, which is trained to analyse, review and critically observe.

She misses her family and her boyfriend in Switzerland, as well skiing, fondue and chocolate. But homesickness? No, none of that (yet). Instead, she is enjoying the privilege afforded to her as a scientist of being able to work anywhere and gain insights into different cultures. The academic culture in the USA is less hierarchical, she says by way of example. However, she did have a lot of freedom in Geneva as well, and "I hope that will be the case here too." She also greatly enjoyed the blend of different cultures in Geneva. "The only difficulty was communicating in French," she confesses. However, this is something she is now working on: she likes to read voraciously and widely – especially in the fantasy genre. Right now, she is reading Harry Potter. In French. This is because, in the long term, she wishes to return to Europe. And who knows: she might come back to Geneva.

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