First Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping early-career researchers promote themselves alongside their papers. Xuan Xie is the first author on ‘Deubiquitylases USP5 and USP13 are recruited to and regulate heat-induced stress granules through their deubiquitylating activities’, published in Journal of Cell Science. Xuan is a PhD student in the lab of Masayuki Komada at the Tokyo Institute of Technology, Yokohama, Japan, investigating the roles of ubiquitylation and deubiquitylation in the regulation of stress granules.

Xuan Xie

How would you explain the main findings of your paper in lay terms?

Stress granules are places that provide shelter for ‘citizens’ that ‘live’ in cells. When cells are subjected to stress, important citizens are provided with so-called ubiquitin chains that makes some of them go to these shelters. Once inside, these citizens stay within stress granules for as long as they have the ubiquitin brand. When the crisis is over, the proteins USP5 and USP13 help these citizens to go back to their normal routine by removing their ubiquitin chains and, furthermore, help to disassemble the ‘shelter houses’. Our study reveals the important role of USP5 and USP13 in the defence system of cells when crisis hits.

Were there any specific challenges associated with this project? If so, how did you overcome them?

One big challenge of our project was the process of optimizing conditions for the assembly and disassembly of stress granules. Probably due to differences in cell conditions or equipment, we struggled to reproduce the induction or clearance of stress granules as other studies had reported. The process to determine the best conditions for our project for us took a lot of time. We overcame the challenge through sheer unremitting efforts in testing the different conditions.

When doing the research, did you have a particular result or ‘eureka’ moment that has stuck with you?

When we were investigating the functions of USP5 and USP13 in stress granules through knockdown experiments, at first we thought that the two proteins might be important for the assembly of stress granules. So when we saw that stress granules were still induced in cells depleted of USP5 and USP13, it was very disappointing. Fortunately, we didn't give up and changed our way of thinking. We considered that, perhaps, instead of assisting the assembly of stress granules, the two proteins accelerate the destabilization of stress granules. Then we saw enhanced induction of stress granules during assembly and delayed disassembly of stress granules during recovery in cells lacking USP5 and USP13. Even now I still remember how thrilled I was at that moment. I believe this could be a particular ‘eureka’ moment that I will never forget.

Why did you choose Journal of Cell Science for your paper?

We chose Journal of Cell Science because it is a well-known journal with a long history in our field. Also, some of my colleagues have published their research in Journal of Cell Science and our group always gets helpful advice from the journal team during the submission process.

Have you had any significant mentors who have helped you beyond supervision in the lab? How was their guidance special?

A lot of people provided generous help in this project. For example, my supervisor, Dr Masayuki Komada gave me a lot of beneficial suggestions when I was lost as to which direction I should take my research. Shunsuke Matsumoto taught me all the basic experiments when I first joined this lab, and also laid the foundation of this project by discovering the colocalization of USP13 with heat-induced stress granules. Dr Toshiaki Fukushima and Dr Akinori Endo not only gave me insightful suggestions but also helped me a lot during the revision of my paper. Dr Yasushi Saeki and Dr Hiroyuki Kawahara provided several important reagents and gave me a lot of help in designing my experiments. I learned a lot from all those brilliant researchers in many ways. Without all the help I received from them, I wouldn't have been able to finish this work.

“For the first time I realized how fascinating and exciting it could be to reveal the secrets of life with all the powerful biological tools we have.”

USP13 (green) is localized to stress granules indicated by PABP1 and G3BP (violet) upon heat stress (44°C for 1 h).

USP13 (green) is localized to stress granules indicated by PABP1 and G3BP (violet) upon heat stress (44°C for 1 h).

What motivated you to pursue a career in science, and what have been the most interesting moments on the path that led you to where you are now?

Since I was a child, I have always shown a great interest in science. I really enjoyed reading science fiction novels and watching science fiction movies and TV series. At school, I put a lot more effort into science-related classes and I felt really satisfied by completing all the science courses with high scores. During my last year in high school, one thing happened that made me determined to become a biologist later. I was selected to take the bonus tests at Peking University for university-autonomous enrolment. During my stay there, I had the chance to visit the different schools at the university and attend lectures introducing these schools. Of all the schools I visited, I was most impressed by the School of Life Sciences. For the first time, I realized how fascinating and exciting it could be to reveal the secrets of life with all the powerful biological tools we have. That year I decided to become a biologist.

Who are your role models in science? Why?

Like a lot of people, my role model in science is Marie Curie. Not only because she was the first person and only woman to win the Nobel Prize twice, but also because her great contribution to radioactivity theory and application of radioactive isotopes laid the foundation for many branches of science today.

What's next for you?

Next, I will begin work at an institute in Japan to do some biochemistry-related research. Then I hope to move to the USA as a postdoc in a lab focused on immunology.

Tell us something interesting about yourself that wouldn't be on your CV

I really love reading novels at home when I have free time. At the moment, I'm obsessed with science fiction novels. I hope that one day I will be able to write some interesting science fiction novels with my biology background.

Xuan Xie's contact details: Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, 4259-S2-18 Nagatsuta, Midori, Yokohama 226-8501, Japan.


Deubiquitylases USP5 and USP13 are recruited to and regulate heat-induced stress granules through their deubiquitylating activities
J. Cell Sci.