Introducing Azadeh Shahsavar

What has been the best moment of your career so far?

I spent all my time and energy during my postdoc on one project because it was quite challenging. I was working on the structure of GlyT1, which had been unsolved for over 20 years. I started this project just after I finished my PhD, as a postdoc in Aarhus University, then I took it to Hamburg with me and then back to Aarhus so I worked on it in for five years in total.

In the spring of 2019, after several months of data collection, we were trying to merge the data together and it finally worked. The first model was a bit low resolution so everything was a bit uncertain. It was a Friday evening and I decided okay, I have saturated the protein with the inhibitor so it should be there and I should be able to see it. I decided to build a part of the protein model in a different way and run the program again and suddenly I could see the density for the inhibitor there and my heart rate raced and I couldn’t sleep for two nights straight. That has been the most rewarding moment. It was really great. 

Why GlyT1?

GlyT1 sits in a critical position in the brain, as it sits right next to NMDA receptor and regulates its function. NMDA receptors are involved with lots of untreatable neurological diseases, like schizophrenia. Because researchers couldn’t target the NMDA receptor directly to treat the negative symptoms, they decided to see if they could indirectly regulate NMDA by inhibiting GlyT1. But then there was over twenty years of research. While they designed potent small molecules that inhibit GlyT1, they haven’t been able to make any of them as a drug so there was some information missing. It was important to solve the structure of GlyT1 bound to its inhibitor to understand how these inhibitors act.

Can you tell me about the serial synchrotron method you have pioneered?

The very first crystals that I got for GlyT1 were, in the best-case scenario, two-five micrometer in size. I never could optimise them to be bigger. It was a long shot to use these in the synchrotron, but I decided to try them out and see if they were protein crystals. It was four o’clock in the morning when it was my turn to test these crystals and I couldn’t believe my eyes that these small crystals were actually protein crystals. I could actually see protein diffractions so that was amazing. 

But since the crystals were very small, the x-rays basically burnt the whole crystal in a couple of seconds. You shoot it and it is gone. What it means is that you get one snapshot. In order to be able to build a 3D model you need to have 360-degree images of what is inside the crystal. In a normal case, you would mount one big crystal at the source of the x-ray beam and then rotate the crystal and collect it along the whole length of the crystal. But this was not possible for GlyT1 crystals.

Instead of one big crystal, with the serial synchrotron method, we collected a fraction of a degree from each crystal but if you have enough number of images and if you put everything together it is like you are rotating a big chunky crystal. This is how we got the structure of GlyT1.

What are you working on now? 

Of course I want to continue working with GlyT1 but in my reading I came across another group of transporters, neutral amino acid transporters. They also sit at the plasma membrane of neurons and it seems like there is kind of a dynamic regulation of NMDA receptor by them and GlyT1. They kind of work together but no one has looked at it really so we will look at the two systems at the same time. I will start with characterizing their functions, their structure and so on. My long-term goal will be to look at them together in tissues.

You have always been intrepid and innovative, can you tell me about your early studies?

I am originally from Iran. In my Bachelor, I studied cell and molecular biology. For my Masters, I studied biophysics where I was introduced to structural biology. At that time, in Iran, we didn’t have access to commercially available kits, plates, and other tools required for crystallography, nor the experience. I basically just read on the internet and studied the books and tried to make my own tools and my own kits. The protein target was easier to work with (than GlyT1) because it was a very stable protein but the conditions I had to work in were more difficult and without really taking any structural biology courses. I always remember the very first time I got my protein crystals, they were actually the very first protein crystals in Iran, so that was really amazing. I flew with them to Liverpool so I could get access to the synchrotron.

And how did you end up in Copenhagen?

I did my PhD here, Michael Gajhede as my main supervisor, together with Jette J. Kastrup and Thomas Balle. After I did my PhD, I moved to Aarhus to Poul Nissen’s group because I wanted to work in membrane proteins. That is where we started working on GlyT1 in collaboration with Roger Dawson (at Roche at that time). With the project, I went to EMBL in Hamburg to the lab of Thomas Schneider. After three years I came back to Poul’s group. The project was finalized in 2021 and then I started to investigate my options.

I did want to stay in Denmark. It is very science friendly I would say and also very friendly to internationals. I decided to apply to Lundbeck for the fellowship. I contacted Michael (Michael Gajhede) and Jette (Jette Sandholm Jensen Kastrup) and they were so kind and so supportive of my application. They made it possible for me to meet Helle (Helle Waagepetersen) who was the Head of Department at that time.

I got really huge support from Helle, Michael and Jette and many group leaders at the Department. I just simply reached out and asked them to read the application and have their feedback and really everybody helped. Of course, Poul and all my colleagues in Aarhus as well. That was something new that I did. I usually would just write the application myself and wouldn’t dare to let other people look at it. But this time it was a one-time chance so I decided to get the criticism before the board of Lundbeck would make a decision.

And what have you been up to since you have been here?

Mainly just practical stuff: finding my way around, setting up protocols, PhD advertisements. But I have also started two new collaborations, with Petrine Wellendorph and Bente Frølund. With Petrine, I will collaborate on GABA transporters. Petrine is an expert in functional studies of transporters so I would very much like to learn from her and her group and also that my students have a place to go and learn from their expertise. It is really nice that they also work with GABA transporters which are in the same family as Glycine transporters so we can learn from each other from two different directions. Then I will work on a project with Bente and Petrine together investigating a new approach of inhibiting GlyT1.

Finally, do you have any advice for young researchers?

It is always a good idea to try different skills and methods when you are exploring. It will become helpful. Of course I am really fond of the structures but it is also as important to  perform functional studies.

For my PhD students we will plan it together in a way so that when they start producing a protein and going for a structure in the very same time, they will also start functional studies, mutational studies. It also makes sense to have the whole package because a structure by itself can only tell you so much. You also need the functional studies and the mutational studies to really understand how the protein behaves. So that is my wish for the PhD students I supervise.

Read more:

To find out more about Azadeh’s research on GlyT1, see: Shahsavar, A., Stohler, P., Bourenkov, G. et al. Structural insights into the inhibition of glycine reuptake. Nature 591, 677–681 (20

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