ABSTRACT
First Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping researchers promote themselves alongside their papers. Anakshi Gayen and Avik Mukherjee are co-first authors on ‘ The mRNA-capping enzyme localizes to stress granules in the cytoplasm and maintains cap homeostasis of target mRNAs’, published in JCS. Anakshi and Avik are both PhD students in the lab of Dr Chandrama Mukherjee at the Institute of Health Sciences, Presidency University, West Bengal, India. There, they study the post transcriptional gene regulation mediated by the cytoplasmic capping enzyme.
Anakshi Gayen
How would you explain the main findings of your paper in lay terms?
A.G. and A.M.: Our work focuses on the mammalian mRNA capping enzyme (CE), a protein that puts a protective structure (known as RNA cap) on different RNAs. We found that this protein moves between the nucleus and cytoplasm. Being primarily a nuclear protein, a small portion of CE comes out of the nucleus through a protein gate in a process mediated by exportin-1. A conserved amino acid stretch of CE contributes to this process. During stress conditions, most of the RNA and protein molecules present in the cytoplasm take shelter in a special compartment (formed only during stress) called stress granules (SGs) and the RNAs lose their protective cap structure. In our study, we found that cytoplasmic CE also resides in these SGs during stress and is dispersed into the cytoplasm when SGs disassemble. In addition, RNAs that depend on CE for their stability can gain the cap structure back when CE is released in the cytoplasm. In a nutshell, we show that the CE moves from the nucleus to the cytoplasm, resides in SGs and recaps RNAs that had lost their caps earlier, thus facilitating the cellular recovery from stress.
Were there any specific challenges associated with this project? If so, how did you overcome them?
A.G.: Every day is a challenge. Our lab got moved to the new campus during COVID-19. Post-COVID, we had to start almost from scratch. That was the most challenging phase for all of us. I was the first person to join the lab and I started working almost alone to optimise the staining procedures and capture good images during the first phase of my work. I had to isolate tiny stress granules using a recently published protocol, which gave me indeed a tough time. Initially, I successfully performed immunostaining with two different fluorescent dyes. However, my experiments stalled when I attempted triple staining. Using multiple control experiments, I spent several weeks in the microscopy room to finally get my first good image with triple staining.
A.M.: A major challenge that I encountered was to identify the position of nuclear export signal (NES) of CE. We first speculated that it might be positioned at either the N-terminal or the C-terminal of CE, but later we were able to locate it at the beginning of GTPase domain of CE through extensive in silico analysis, followed by wet lab validation.
When doing the research, did you have a particular result or ‘eureka’ moment that has stuck with you?
A.G.: I cannot recall any eureka moment but for me every experiment, how trivial it seems, is important, as these small beads (of results) make a necklace (of a story).
A.M.: A special moment for me was when we observed under the microscope that a single leucine to alanine mutation in the NES led to almost complete loss of nuclear export of CE. This finding was also very special because it shows CE is exported to the cytoplasm from the nucleus to play its cytoplasmic roles.
Why did you choose Journal of Cell Science for your paper?
A.G. and A.M.: Journal of Cell Science is quite a reputed and a top tier journal in the field of cell biology and has a broad range of readers. Its intense peer review procedure and good quality articles contribute enormously to the scientific community. We desired to publish our work in a journal where our work would align with the identity of the journal, so JCS was the best choice for us.
Stress granule formation in RPE1 cells upon sodium arsenite stress. CE is shown in green and eIF3 is shown in red.
Stress granule formation in RPE1 cells upon sodium arsenite stress. CE is shown in green and eIF3 is shown in red.
Have you had any significant mentors who have helped you beyond supervision in the lab? How was their guidance special?
A.G.: I got immense support from my supervisor Dr Chandrama Mukherjee. As I was the first person to join her lab, I had no senior to teach me. My supervisor was the person who helped me design all the experiments, helped me understand the research problems and taught all the techniques and lab-related safety measures. I am also incredibly grateful to Dr Shubhra Majumder for all his relentless mentorship in imaging experiments. He has helped me through many ideas and clarified the concepts of good images versus bad images.
A.M.: My supervisor Dr Chandrama Mukherjee has guided me throughout, especially when we are building new strategies to address our research questions. Also, I have learnt confocal image processing and many different quantitative tools from Dr Shubhra Majumder.
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?
A.G.: Being raised in a Bengali middle-class family, all I heard was that I should become a doctor or an engineer when I grew up. But during my high school days, I was inspired by one of my aunts, who was in this field and used to tell me about her works and journey, which fascinated me. In a summer internship post graduation, I worked in a lab and had my first opportunity to understand the intricacies and methodologies of experiments, thereby deducing results. This experience ultimately led me to pursue a career in science.
A.M.: The cumulative contributions in a particular field always serve as a strong motivation for me to pursue research in a science field. For me, the best part of science is building a new hypothesis and designing research methodologies to test it. It is indeed intriguing when a researcher investigates an aspect that has never been addressed before.
Who are your role models in science? Why?
A.G.: Every breakthrough in science is very exciting. The rigorous work and journey of scientists, especially women scientists as they discover new things, thrills me. Personally, I was extremely motivated by one of my uncles, who always encouraged me to take up challenges and to never give up.
A.M.: Acharya Jagadish Chandra Bose and Dr A. P. J. Abdul Kalam are my role models in science. Both of them pioneered contributions in Indian science. They inspired many generations to pursue a career in science.
What's next for you?
A.G.: At present, I am working on other projects in the lab and trying to finish my PhD soon. Later, I want to do postdoctoral research in the RNA biology field.
A.M.: After the completion of my PhD, I wish to pursue my postdoctoral research in the field of RNA therapeutics.
Tell us something interesting about yourself that wouldn't be on your CV
A.G.: During leisure, I like to cook and experiment with dishes. It is also a stress buster for me. I also like to travel and discover new places. I find solace in painting but sometimes it's hard to find time for these little things.
A.M.: I am a travel enthusiast who loves to trek, hike and roam amidst nature. I am also a passionate amateur photographer and food explorer.
Anakshi Gayen's and Avik Mukherjee's contact details: Institute of Health Sciences, Presidency University, Plot No. DG/02/02, Premises No. 14-0358, Action Area 1D, Newtown, New Town, West Bengal 700156, India.
E-mails: [email protected]; [email protected]
