The contribution of RNA to heterochromatin
Abstract/Contents
- Abstract
- Accurate chromosome segregation is essential for proper cell division and normal organismal development in all eukaryotes. Chromosome segregation errors generate aneuploid cells that cause human genetic disease and characterize most human cancers. Our long term goal is to understand the cellular mechanisms that ensure accurate chromosome segregation. During cell division, pairs of replicated chromosomes must remain linked until anaphase in order to properly segregate to daughter cells. The primary sites for cohesion between sister chromatids exist at the heterochromatic outer regions of the centromere, called pericentric heterochromatin. Disruption of this heterochromatin domain disturbs cohesion, resulting in chromosome segregation errors and aneuploidy. The concept of non-coding RNAs directing chromatin modifications is a growing paradigm in cell biology and substantial evidence implicates non-coding RNAs in the formation of human pericentric heterochromatin. Unraveling the RNA-dependent mechanisms of pericentric heterochromatin formation has clear implications in human disease; dysfunctional regulation of pericentric transcription characterizes numerous cancers in mouse and humans and is thought to contribute to genomic instability. We discovered that RNA remains physically attached to human mitotic chromosomes, and is enriched at pericentric regions. We found that SUV39H1 and SUV39H2, two histone methyltransferases critical for heterochromatin formation, directly bind RNA in vitro and associate with RNA transcribed from pericentric regions in vivo. We found that treatment of mitotic chromosomes with single-stranded ribonuclease decreases SUV39H1 localization to pericentric regions, suggesting an RNA-dependent mechanism for SUV39H1 targeting. To determine to role of direct RNA binding by SUV39H1, we mapped the minimal RNA binding domain of SUV39H1 to its chromodomain, and identified mutants that severely disrupt direct RNA binding in vitro. RNA binding-deficient SUV39H1 mutants display a marked impairment of localization to pericentric regions in vivo, and are generally less stably associated with chromatin. These results suggest a novel role for non-coding RNA in the targeting of SUV39H1 to pericentric heterochromatin. We propose a model in which both direct RNA binding, in addition to histone binding, differentially contribute to the affinity of SUV39H1 for pericentric heterochromatin, ensuring faithful heterochromatic silencing of a chromatin domain that is vital for proper chromosome segregation.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2015 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Yewdell, William T |
|---|---|
| Associated with | Stanford University, Department of Biochemistry. |
| Primary advisor | Straight, Aaron, 1966- |
| Thesis advisor | Straight, Aaron, 1966- |
| Thesis advisor | Das, Rhiju |
| Thesis advisor | Gozani, Or Pinchas |
| Thesis advisor | Pfeffer, Suzanne |
| Advisor | Das, Rhiju |
| Advisor | Gozani, Or Pinchas |
| Advisor | Pfeffer, Suzanne |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | William T. Yewdell. |
|---|---|
| Note | Submitted to the Department of Biochemistry. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2015. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2015 by William Theodore Yewdell
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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