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. Jo Strachan is first author on ‘ SUMOylation regulates Lem2 function in centromere clustering and silencing’, published in JCS. Jo conducted the research described in this article while a postdoc in Elizabeth Bayne's lab at University of Edinburgh, UK. She is now a postdoc in the lab of Steven Spoel at University of Edinburgh. Her interest is in exploring the diverse roles of the small protein modifiers ubiquitin and SUMO.

Jo Strachan

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

For cells to divide, it is important that the genetic material (encoded in chromosomes) is split evenly between daughter cells. A protein called Lem2 is found in the nucleus of the cell and plays a number of roles at the centromere region of chromosomes, including grouping chromosomes and turning off specific genes. Both of these processes are important for successful cell division. SUMO is a protein that can be attached on to other proteins, including Lem2. Here, we found that attaching SUMO to Lem2 makes Lem2 better at grouping chromosomes, but makes it worse at turning off genes. Therefore, tagging of Lem2 with SUMO acts like a ‘molecular switch’ by controlling the function of Lem2 in nuclear processes that are important for cell division.

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

Post-translational modifications by ubiquitin and SUMO can often be transient and labile. We needed to carefully optimise experimental conditions to ensure we retained these modifications. The importance of networking and discussion cannot be overstated as the advice and reagents provided by other members of the scientific community were essential for our success.

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

The discovery that increasing SUMOylation of Lem2 can enhance centromere clustering was entirely unexpected and very exciting. Centromere clustering mechanisms remain elusive, and the concept that SUMO may act as a ‘molecular glue’ to enhance protein–protein interactions is an attractive model, given the large number of centromere-associated proteins that have been found to be SUMOylated.

Representative images from two-colour live cell imaging of GFP–Cnp1 and Sid4–RFP. GFP–Cnp1 marks the centromere and Sid4–RFP the spindle pole body. Dotted lines indicate cell boundaries.

Representative images from two-colour live cell imaging of GFP–Cnp1 and Sid4–RFP. GFP–Cnp1 marks the centromere and Sid4–RFP the spindle pole body. Dotted lines indicate cell boundaries.

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

In addition to its dedication to communicating and understanding all aspects of cell biology, Journal of Cell Science is a highly reputable journal that has a wide readership and is committed to supporting people within the cell biology community. Therefore, we felt this journal was an excellent fit for our publication.

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?

For as long as I can remember, I've been fascinated about how things work and with solving puzzles. I learned a lot by studying biology at school and discovering the fields of cell biology and genetics, but I also came to realise how little I knew. More importantly, I realised there are so many things that indeed no-one knows yet, and this only made me want to find out more. Once I began my PhD, I discovered the joy of every successful experiment, and the even greater satisfaction of solving the problems with the less successful experiments.

What's next for you?

I have recently joined the Spoel lab at the University of Edinburgh to start an exciting new project that builds upon my extensive experience investigating small protein modifiers; but this time I will be exploring ubiquitin function in plants.

Jo Strachan’s contact details: Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FF, UK.

E-mail: jo.strachan@ed.ac.uk

Strachan
,
J.
,
Leidecker
,
O.
,
Spanos
,
C.
,
Le Coz
,
C.
,
Chapman
,
E.
,
Arsenijevic
,
A.
,
Zhang
,
H.
,
Zhao
,
N.
,
Spoel
,
S. H.
and
Bayne
,
E. H.
(
2023
).
SUMOylation regulates Lem2 function in centromere clustering and silencing
.
J. Cell Sci.
136
,
jcs260868
.