Biophysical Society Bulletin | June 2019

Biophysicist in Profile

Cristina Paulino Areas of Research Fundamental understanding of how membrane transporters and channels work

Institution University of Groningen, The Netherlands

At-a-Glance

Cristina Paulino is an assistant professor and head of the electron microscopy unit at the Univer- sity of Groningen, The Netherlands. Her interest in membrane proteins began during her un- dergraduate years and has continued ever since. Her work focuses in understanding the struc- ture-function relationship that underlies the mechanism of transport of membrane proteins.

Cristina Paulino

Growing up, none of Cristina Paulino’s family members were involved in science. She comes from a Portuguese lower-middle class family; her father was a waiter and in between jobs man- aged his own café with the assistance of her mother. Although born in Germany as a first-generation immigrant, her family moved back to Portugal where she was raised for most of her youth. They later relocated back to Germany where she finished secondary school. Paulino’s interest in science stems back to her early childhood, when she was quite vocal in school. She recalls that her teachers had a hard time with her, as she asked many questions regarding the subject at hand. “I was mostly interested in chemistry and when I had to choose what exactly to study I decided to go for a biological applica- tion of chemistry and studied biochemistry,” says Paulino. She obtained her bachelor’s and master’s degrees in biochemistry in 2006 and 2008, respectively, from the Heinrich-Heine University in Düsseldorf, Germany. “This is when I also became interested in biophysics and structural biology,” she recalls and she decided to explore it further as a PhD student at the Max-Planck-Institute of Biophysics in Frankfurt, Germany. For her postdoctoral work, she joined the lab of Raimund Dutzler at the University of Zurich, Switzerland, in 2014. “There I setup the technique of high-res- olution single particle cryo-electron microscopy, which we then successfully employed to study membrane transporters and channels.” Paulino’s fascination with membrane proteins emerged during her undergraduate years and has persisted ever since. Her train- ing and interest in cryo-electron microscopy (cryo-EM) started during her PhD work. Paulino expalined, “At this point EMwas not perceived as a relevant technique in structural biology and we were often called ‘blobologists,’ referring to the low-reso- lution densities we obtained.” Her PhD supervisor and mentor Werner Kühlbrandt , who is one of the pioneers in the cryo-EM field, noted Paulino’s inclination for challenges which then created a path for her journey. She was a well-trained electron microscopist by the time her PhD studies were complete, but she had also noticed that the field had changed. “Suddenly, what we could achieve with cryo-EMwas mind-blowing, making it an in-

dispensable technique in structural biology.” She said “Being one of the few people from the ‘old cryo-EM generation’ obviously helped, our expertise was in high demand and a whole new level of research questions [were] waiting to be answered.” Paulino currently serves as an assistant professor on a ten- ure track, and is also the head of the electron microscopy unit and facility at the University of Groningen, The Netherlands. In her group, she focuses on understanding the structure-func- tion relationship that underlies the mechanism of transport of membrane proteins. A colleague of Paulino, Dirk Slotboom , a professor in structural membrane biology in Groningen, admires her professionalism and hard-working demeanor. “Cristina does not [like] cold weather, yet she pushed her boundaries on a cross-country skiing trip in the Swiss Alps during [a] lab retreat. She almost collapsed, but pulled through. Yet another sign of her not giving up,” says Slotboom.

The golden EM trophy, is one of the things Paulino introduced in her group to show appreciation and boost the motivation within and with lab members. As she explains: “This trophy is passed to everyone in the group that had a nice accomplishment (pub- lished, unpublished, for research or a big life event, or simply for a great idea or support). This event gets a spot on the ‘wall of fame,’ which hangs next to the ‘wall of shame.’ Mistakes happen, we learn from them, and they can a good reason for a laugh, too.”

June 2019

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