Publication Date
2022
Document Type
Dissertation
Committee Members
Paula Bubulya, Ph.D. (Advisor); Quan Zhong, Ph.D. (Committee Member); Labib Rouhana, Ph.D. (Committee Member); Weiwen Long, Ph.D. (Committee Member); Michael Leffak, Ph.D. (Committee Member)
Degree Name
Doctor of Philosophy (PhD)
Abstract
Gene expression in mammalian cells requires complex nuclear choreography, and there is increasing evidence that spatiotemporal organization of chromatin and nuclear compartments plays an important role in gene expression. In this dissertation, I examined the function of SON, a splicing factor with a known role in nuclear organization, in chromatin-mediated gene expression. SON association with a transcriptionally inactive U2OS 2-6-3 reporter gene array provided a useful model to study SON’s chromatin dynamics. I demonstrated that SON associates with the inactive but not the activated array, and that SON’s RNA binding domains are not necessary for that association. Second, I discovered a new role for SON in maintaining chromatin condensation. Whereas chromatin decondensation is typically correlated with transcription activation, I have demonstrated that reporter transcripts are not produced at decondensed SON-depleted U2OS 2-6-3 reporter gene loci, and that SON-depleted loci contain histone H3 that is trimethylated on lysine 9, a marker for transcriptionally silent chromatin. We found that SON depleted reporter loci are still transcriptionally activatable, and that inhibiting transcription elongation is not sufficient to condense the enlarged SON depleted reporter locus. These findings suggest that higher order chromatin structure and transcription activation are functionally distinct mechanisms of gene regulation that can be uncoupled. Finally, I investigated SON’s role in genome-wide chromatin organization. SON-depleted cells are more susceptible to DNase digestion, implicating SON in the maintenance of chromatin stability globally. In conclusion, this study demonstrates a new function for the splicing factor SON in maintaining chromatin organization.
Page Count
188
Department or Program
Biomedical Sciences
Year Degree Awarded
2022
Copyright
Copyright 2022, all rights reserved. My ETD will be available under the "Fair Use" terms of copyright law.
ORCID ID
0000-0002-5016-1086
