Facebook Pixel Code
Banner image
About the Institute

Profile of Danielle Johnson

Staff photo
Dr. Danielle Johonson

Dr. Danielle Johnson, PhD

  • Postdoctoral Fellow

1. Where are you from?/Where did you study?
I grew up in Calgary, Alberta where I completed my undergraduate degree in biology at the University of Calgary. Through the guidance of excellent professors, I became interested in ion transport in the kidney. Then, I attended the University of Alberta and completed my PhD in Dr. Joe Casey’s lab where I became intrigued by pH and pH regulation. Coming to SickKids for my post-doctoral fellowship with Dr. Sergio Grinstein was a natural progression since he’s one of the best cell biologists in the field of pH and ion regulation. 

2. What are you researching right now?
My main area of study is pH regulation; the balance of acids and bases in our bodies. Most cellular processes are exquisitely sensitive to pH, so it’s very important to understand how pH is regulated. Cells are compartmentalized by membrane-bound organelles that carry out different physiological functions. There are pH-regulatory transmembrane proteins that regulate pH, both in the plasma membrane of the cell and in the membranes inside the cell. Failure of these proteins to regulate pH properly can lead to many pathophysiologies. Understanding pH regulation in a healthy cell will help us understand pH regulation inside an unhealthy cell.

My passion for pH and cell biology led me to study lysosomes. Lysosomes are the terminal organelles of the endocytic pathway, and are characterized by a highly acidic lumen that is rich in hydrolytic enzymes. Lysosome functions are diverse, but include digestion of macromolecules, degradation of organelles and elimination of pathogens. It is fascinating to study the relationship between lysosome position within the cell, luminal pH and cellular trafficking events.

3. Who is your all-time favourite scientist and why?
My favourite scientist is Roger Tsien, one of the winners of the 2008 Nobel Prize in chemistry. Reading his literature and studying his work is both visually and intellectually stimulating. The scientific questions that he answers using florescent protein technology are astounding. In fact, Tsien inspired me to become one of the first scientists in our lab to use florescent proteins to report on intracellular environments.

I was fortunate to attend a talk where Tsien discussed some of his work shortly after being awarded the Nobel Prize. It was completely mind-blowing to witness his approach to answering important biological questions. It takes skill to answer difficult questions in the simplest way possible. That is something that my supervisor Dr. Grinstein also excels at, and it is something that I try to do in my research.

4. What in your opinion is the most important scientific breakthrough and why?
That is a very hard question! Working in a lab with a focus on immunology, I believe the discovery of the vaccine was the most important scientific breakthrough. It has saved many lives and prevented many diseases making it easy to see its dramatic health implications.

5. What are your major interests outside the lab?
One of my passions is rock climbing. I love the physical and intellectual challenges of the sport. In rock climbing, the physical strength to climb will only get you so far. If you get stuck in a position, you need to sit back, take a few breaths and look at how you could approach the problem differently. There is always a way to overcome the obstacle and discovering that is very exciting! I also love the physicality of rock climbing; whether I’m climbing a harder grade or focusing on improving my footwork or working on a difficult move, it’s great to get a good workout while enjoying the social environment of the sport.

My other favourite sport is snowboarding. I haven’t hit the slopes as much since I moved to Ontario but I used to snowboard all the time in the Rockies.

6. Why science?
I chose science in part because of the influence of my teachers. Growing up, I had two passions: studying English literature and studying science. I always loved both subjects, but two of my high school biology teachers had a life-changing impact on me. Their passion for the subject and care for their students inspired me immensely. Of course, I already found science fascinating so it was the combination of both interest and inspiration that pushed me to pursue biology.

During my undergraduate degree I majored in biology and minored in English but I still wondered which field to pursue. In the last year of my undergrad I was fortunate to take a course taught by Dr. William Cole, a fantastic professor at the University of Calgary, who asked us to do a project based on our favourite organ system. I chose the kidney because I was interested in understanding how different transport proteins regulate pH and ion balance. It was through this assignment and by keeping up-to-date with current literature and research on the kidney and ion regulation, that I found Dr. Joe Casey. I moved to Edmonton to pursue my PhD and my love of science continued to grow.

Science is exciting because there is always a question to answer and new opportunities to pursue and learn from. Working in an environment conducive to continuous learning and being able to share my love and passion for science with others is a very gratifying experience.

7. Why SickKids?
I chose SickKids largely to work with Dr. Grinstein, who influenced me through his research on pH and ion transport even before we met. When it came time to look for a post-doctoral fellowship, I wanted to continue working in the field of pH regulation and Dr. Grinstein was a natural next step. I thought I should just shoot for the stars and pick the best lab and so I did!

8. What is the most controversial question in your field right now?
There are many things we are beginning to appreciate that will change our understanding of cell biology. If you look at a cell biology textbook for example, there is the idea that all organelles are homogeneous. Through my studies, and others, however, we are beginning to learn that organelles, and lysosomes in particular, are actually very heterogeneous. Cell biologists are now starting to change their static view of lysosomes and appreciate that they are more complex and dynamic than originally thought. I believe this dynamism and complexity applies to everything in a cell.

The tools, techniques and knowledge we use to further probe the function of these organelles will also become increasingly important in studying disease state. Lysosomes are linked to many neurodegenerative diseases and we need to understand their function in a healthy state to know what happens when dysfunction occurs. I think this is where the field is progressing –finding a deeper understanding of the heterogeneity of different cellular systems.

9. What are you reading right now?
I just finished a book called Three Day Road by Joseph Boyden. It tells the story about how a native Canadian male incorporated his culture and beliefs into the experience of fighting in the First World War. The narrative weaves his own story with that of his aunt during his journey home. This journey began a healing process, where he came to terms with whom he was and who he will be in the future. It was a very touching and well-written piece.

10. If you could give one piece of advice to someone considering a research career, what would it be?
The best piece of advice would be to find your passion because as long as you’re passionate about what you’re doing in life you’ll be driven to succeed. There will always be roadblocks along the way and you won’t always know exactly where you’ll end up but if you are passionate and have faith in yourself you’ll end up being successful.

11. What does the SickKids Centre for Research and Learning mean to you?
The Peter Gilgan Centre for Research and Learning is fantastic! The aesthetics of the building are wonderful with the floor-to-ceiling windows, natural lighting and the beautiful view. Just the experience of coming up the elevator in the morning and looking out at the lake for a few minutes gets you in the right mindset and inspires you to be happy, no matter what. The open lab and open floor concepts allow scientists to interact with each other both personally and professionally. It fosters an excellent environment, creating discussions and support. Aside from the joy of being able to work in such a fantastic building with fantastic people, the Peter Gilgan Centre for Research and Learning also serves as a very good landmark in Toronto. The entire city watched the construction of the building and watched as we moved in, inspiring dialogue about what happens here. It’s a big deal for SickKids to have such an outstanding building.

July 2015