Poster abstracts
Poster number 26 submitted by Erika Calle Urgiles
Live Cell Imaging of Cell Cycle Stages And Its Effect on Stress Response
Erika Calle Urgiles (University of Michigan Program in Biomedical Sciences), Ben Dodd (University of Michigan Department of Human Genetics and Center for RNA Biomedicine), Stephanie Moon (University of Michigan Department of Human Genetics and Center for RNA Biomedicine)
Abstract:
The integrated stress response (ISR) promotes cell survival of stress in
eukaryotic cells through transcriptional and translational adaptation. Activation of the
ISR by stress-sensing kinases allows for the selective translation of stress-induced
genes and repression of global translation(2). Translationally repressed mRNAs
condense into stress granules, which may sequester RNAs, small ribosomal subunits,
and pre-initiation complexes from degradation and translation machinery. Further,
mutations in stress granule RNA binding proteins are associated with amyotrophic
lateral sclerosis and frontotemporal dementia (4). Stress granules and the ISR may be
especially important in post-mitotic cells like neurons which are no longer able to go
through mitosis or regenerate. Also, dysregulation of the ISR has been associated with
cancer cells, which have a perturbed cell cycle and exhibit aberrant cell survival (1).
Therefore, investigating whether and how the cell cycle plays a role in stress response
will be important in gaining insight into neurodegenerative disease and cancer. Our
hypothesis is that the cell cycle stage affects a cell’s stress response. To test this, we
will track stress granule formation, induced upon arsenite stress, throughout each cell
cycle stage over a 24 hour live cell imaging period. We have expressed human bone
osteosarcoma epithelial cells with mScarlet-G3BP1, which marks the time at which
stress granules form and DHB-mVenus marks cell cycle change. The DHB-mVenus
reporter alters between a cytoplasmic localization during dephosphorylation by
cyclin-dependent kinase 2 (CDK2) to a nuclear localization during phosphorylation in
newly divided cells (3). CDK inhibitors, Palbociclib and RO-3306, offer another avenue
to track cell cycle change since they trap and synchronize cells in the G1 and G2/M
border cycle stage respectively. Through this research, we can learn if the cell cycle is
interrelated to a cell’s integrated stress response when forced into stressful conditions.
Our findings can be applied to the role that the cell cycle and cell differentiation plays in
the development of cancer and neurodegenerative disease.
References:
1. Costa-Mattioli, M., & Walter, P. (2020). The integrated stress response: From
mechanism to disease. Science (New York, N.Y.), 368(6489).
2. English, A. M., Green, K. M., & Moon, S. L. (2022). A (dis)integrated stress response:
Genetic diseases of eIF2α regulators. Wiley interdisciplinary reviews. RNA,
13(3), e1689.
3. Spencer, S. L., Cappell, S. D., Tsai, F. C., Overton, K. W., Wang, C. L., & Meyer, T.
(2013). The proliferation-quiescence decision is controlled by a bifurcation in
CDK2 activity at mitotic exit. Cell, 155(2), 369–383.
4. Vance, C., Rogelj, B., Hortobágyi, T., De Vos, K. J., Nishimura, A. L., Sreedharan, J.,
… Shaw, C. E. (2009). Mutations in FUS, an RNA processing protein, cause
familial amyotrophic lateral sclerosis type 6. Science (New York, N.Y.),
323(5918), 1208–1211.
Keywords: integrated stress response, translation, neurodegenerative