Poster abstracts

Poster number 19 submitted by Shivang Bhaskar

Effect of nucleolar stress on the localization of SNUL-1 ncRNA

Shivang Bhaskar (Department of Cell and Developmental Biology, University of Illinois Urbana-Champaign), Minxue Liu (Department of Cell and Developmental Biology, University of Illinois Urbana-Champaign), Oraya J. Zinder (Department of Cell and Developmental Biology, University of Illinois Urbana-Champaign), Supriya G. Prasanth (Department of Cell and Developmental Biology, University of Illinois Urbana-Champaign), Kannanganattu V. Prasanth (Department of Cell and Developmental Biology, University of Illinois Urbana-Champaign)

Abstract:
Nucleoli are membraneless nuclear substructures that form around tandem repeats of ribosomal RNA (rRNA) genes found on the 5 acrocentric chromosomes in humans (13, 14, 15, 21, and 22). As the site of rRNA transcription and processing and ribosome maturation, the nucleolus plays an integral role in ribosome biogenesis. In addition to harboring rDNA, nucleoli have been shown to enact distinct responses to various cellular stressors1. Nucleolar stress induces a range of reactions in nucleoli, including morphological changes and translocation of nucleolar proteins to the nucleoplasm. Nucleolar non-coding RNAs (ncRNAs), such as rIGSRNA2, have also been demonstrated to contribute to the nucleolar stress response. We have previously demonstrated that the nucleolar ncRNA SNUL-1, part of the SNUL family of ncRNAs, regulates rRNA expression. SNUL-1 localizes in a single nucleolus in diploid human cell lines. However, the effect of nucleolar stress on the localization of SNUL-1 has not been characterized. In the present study, several cellular stressors have been utilized in the human pseudo-diploid cell line RPE1 to investigate changes to the localization of the SNUL-1 ncRNA under nucleolar stress conditions. Results from the study have revealed that SNUL-1 localization is altered in response to certain nucleolar stressors but maintains its typical single-nucleolus association under other stress conditions. Furthermore, in response to certain nucleolar stress conditions (including treatment with camptothecin or flavopiridol), SNUL-1 ncRNA adopts ring-like structures around the nucleolar peripheries. These findings demonstrate that SNUL-1’s localization under nucleolar stress is stressor-dependent and provide the basis for further understanding of how SNUL-1 participates in the nucleolar stress response.

References:
1. Yang K., Yang J., Yi J. (2018). Nucleolar Stress: hallmarks, sensing mechanism and diseases. Cell Stress, 2(6), 125-140. 10.15698/cst2018.06.139
2. Wang, M., Tao, X., Jacob, M. D., et al. (2018). Stress-Induced Low Complexity RNA Activates Physiological Amyloidogenesis. Cell Reports, 24, 1713-1721. https://doi.org/10.1016/j.celrep.2018.07.040

Keywords: Nucleolar Stress, rRNA, Nucleolus