Characterization of centromere assembly machinery interactions in Xenopus laevis
Abstract/Contents
- Abstract
- Centromeres are specialized chromosomal regions that mediate chromosome segregation during mitosis by providing the assembly site for the mitotic kinetochore. Centromeres are epigenetically defined by the incorporation of the histone H3 variant, centromere protein A (CENP-A), into centromeric nucleosomes. In vertebrates, CENP-A nucleosome assembly is coupled to the exit from mitosis and requires the targeting of soluble CENP-A to the centromere in complex with its histone chaperone the holliday junction recognition protein (HJURP). Two centromere specific factors, centromere protein C (CENP-C) and the Mis18 complex (Mis18α, Mis18β, and M18BP1) are required for recruiting HJURP to centromeres. However, how these factors coordinate the cell cycle specific assembly of CENP-A at centromeres is poorly understood. Using a cell free system for centromere assembly in Xenopus laevis frog egg extracts, I discovered a mechanism for regulating the cell cycle dependent interaction between HJURP and CENP-C. Non-phosphorylatable mutations in HJURP serine 220 result in constitutive interaction between HJURP and CENP-C in metaphase yet do not trigger new CENP-A assembly, while phosphomimetic mutations prevent HJURP binding to CENP-C and inhibit new CENP-A assembly. I show that the inhibitory activity that prevents HJURP localization and new CENP-A assembly in metaphase is due to competition for HJURP's binding site on CENP-C by M18BP1.S. My results identify two important mechanisms for coupling CENP-A assembly to the cell cycle; negative regulation of HJURP-CENP-C interaction by mitotic phosphorylation and competitive inhibition of metaphase HJURP-CENP-C interaction by M18BP1.S.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2021; ©2021 |
| Publication date | 2021; 2021 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Flores Servin, Julio Cesar |
|---|---|
| Degree supervisor | Straight, Aaron, 1966- |
| Thesis advisor | Straight, Aaron, 1966- |
| Thesis advisor | Feldman, Jessica L |
| Thesis advisor | Gozani, Or Pinchas |
| Thesis advisor | Rohatgi, Rajat |
| Degree committee member | Feldman, Jessica L |
| Degree committee member | Gozani, Or Pinchas |
| Degree committee member | Rohatgi, Rajat |
| Associated with | Stanford University, Department of Biology |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Julio Cesar Flores Servin. |
|---|---|
| Note | Submitted to the Department of Biology. |
| Thesis | Thesis Ph.D. Stanford University 2021. |
| Location | https://purl.stanford.edu/mb458hk7037 |
Access conditions
- Copyright
- © 2021 by Julio Cesar Flores Servin
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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