otub-3 is a Novel Regulator of Centriole Biogenesis

dc.contributor.advisorTarailo-Graovac, Maja
dc.contributor.authorNickel, Kyle
dc.contributor.committeememberGrewal, Savraj
dc.contributor.committeememberGuo, Jiami
dc.date.accessioned2024-09-11T14:08:01Z
dc.date.available2024-09-11T14:08:01Z
dc.date.issued2024-09-06
dc.description.abstractCentrioles are organelles in eukaryotic cells with essential functions including organizing the microtubule cytoskeleton and orchestrating mitotic spindle formation. Proper control of centriole number is crucial, as deviations have deleterious consequences. Centriole duplication in Caenorhabditis elegans is initiated in S-phase by the ZYG-1 kinase. Disruption of zyg-1 results in embryonic arrest, as centrioles fail to duplicate. Many negative regulators of centriole biogenesis are suppressors of zyg-1 and can rescue centriole biogenesis and viability in worms carrying a hypomorphic zyg-1 allele. In this thesis, I characterize the role of otub-3, a novel suppressor of zyg-1 identified in a high-throughput genetic screen of zyg-1 in the Tarailo-Graovac lab. I demonstrate that loss of otub-3 rescues viability and centriole duplication in a zyg-1 mutant background without causing centriole amplification in a wildtype background. otub-3 encodes a functional deubiquitinase enzyme and disrupting the catalytic function of OTUB-3 is sufficient to suppress zyg-1. Additionally, loss of otub-3 suppresses spd-2 and zyg-1, but not sas-6, demonstrating genetic relationships with early regulators of centriole biogenesis. A deletion mutant for otub-3 displays normal mitotic timing, suggesting that the interaction between otub-3 and the centriole is independent of the APC/C pathway. OTUB-3 is cytoplasmic and excluded from the nucleus, indicating a potential role in post-translational regulation of centriole regulators. Loss of otub-3 reduces brood size but does not cause embryonic lethality, indicating otub-3 is non-essential and implicated in fertility. Immunoprecipitation followed by mass-spectrometry revealed a physical interaction between OTUB-3 and KIN-3, a known negative regulator of centriole biogenesis. Genetic experiments revealed a genetic interaction between otub-3 and kin-3 as well, positioning otub-3 within a regulatory network functioning to regulate C. elegans centriole biogenesis. This study establishes OTUB-3 as the first deubiquitinase implicated in centriole biogenesis in C. elegans. In addition, this work provides insight into the etiology of human disease. OTUD6B, the human ortholog of otub-3, is linked via an unknown mechanism with primary microcephaly, a genetic disorder commonly caused by centriolar defects. This thesis is the first work to demonstrate a link between an ortholog of OTUD6B and centriole biogenesis, giving a possible mechanism for OTUD6B-linked microcephaly.
dc.identifier.citationNickel, K. (2024). otub-3 is a novel regulator of centriole biogenesis (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.
dc.identifier.urihttps://hdl.handle.net/1880/119644
dc.language.isoen
dc.publisher.facultyArts
dc.publisher.institutionUniversity of Calgary
dc.rightsUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subjectCentriole
dc.subjectForward Genetic Screen
dc.subjectGenetic Modifier
dc.subjectSuppressor
dc.subjectDeubiquitinase
dc.subjectUbiquitin Biology
dc.subjectMicrocephaly
dc.subject.classificationBiology--Cell
dc.subject.classificationBiology--Molecular
dc.subject.classificationGenetics
dc.titleotub-3 is a Novel Regulator of Centriole Biogenesis
dc.typemaster thesis
thesis.degree.disciplineMedicine – Biochemistry and Molecular Biology
thesis.degree.grantorUniversity of Calgary
thesis.degree.nameMaster of Science (MSc)
ucalgary.thesis.accesssetbystudentI require a thesis withhold – I need to delay the release of my thesis due to a patent application, and other reasons outlined in the link above. I have/will need to submit a thesis withhold application.
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