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dc.contributor.authorOgunrinde, Adenikeen
dc.date2016-01-11 12:48:59.886
dc.date.accessioned2016-01-14T18:41:29Z
dc.date.issued2016-01-14
dc.identifier.urihttp://hdl.handle.net/1974/13927
dc.descriptionThesis (Master, Biology) -- Queen's University, 2016-01-11 12:48:59.886en
dc.description.abstractPlants, as sessile organisms, require rapid and efficient signalling pathways in order to respond to environmental stimuli and to coordinate developmental programs. Stimulus-specific transient elevations in free cytosolic calcium ([Ca2+]cyt ), otherwise referred to as calcium (Ca2+) signals, are known to encode information regarding external stressors or internal developmental cues, which can be interpreted by Ca2+-binding proteins (CBPs), termed Ca2+ sensors. Though much is known about Calmodulin (CaM), the most abundant Ca2+ sensor, relatively little is known about the CaM-like family of Ca2+ sensors (CMLs), which comprise a 50-member family in Arabidopsis thaliana (Arabidopsis). In order to understand how CMLs contribute to Ca2+ signalling, it is necessary to study their biochemistry and physiological roles. In this study, two paralogous CMLs of unknown function, CML15 and CML16, were studied through a combination of approaches including protein biochemistry, gene promoter-reporter analysis, and physiological assays. Promoter-reporter analysis demonstrated that the CML16 promoter is constitutively active across a range of Arabidopsis tissues, whereas CML15 promoter activity is restricted to the stamen. Among a range of environmental conditions tested, salinity stress was observed to inhibit CML16 promoter activity. Phenotypic analysis, across a range of growth stages, of gene-knockout transgenic plants lacking either CML15 or CML16 did not reveal any differences from wild-type plants. Biochemical characterization of CML15 and CML16 indicated that these CMLs possess properties consistent with their predicted roles as Ca2+ sensors. CML15 and CML16 were observed to undergo Ca2+-dependent conformational changes that expose hydrophobic residues, likely for interaction with unknown protein targets. Furthermore, both CMLs were found to bind magnesium (Mg2+) in the absence of Ca2+, but demonstrated high affinity Ca2+ binding in the presence of Mg2+. Putative protein targets for CML15 and CML16 were isolated by yeast two-hybrid screening although the physiological relevance of these as CML effectors remains unknown. Collectively, my data reveals that these CMLs behave biochemically like typical Ca2+ sensors, possess distinct and largely non-overlapping gene expression patterns, and do not appear to be critical for Arabidopsis growth and development under typical growth conditions.en
dc.language.isoengen
dc.relation.ispartofseriesCanadian thesesen
dc.rightsQueen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canadaen
dc.rightsProQuest PhD and Master's Theses International Dissemination Agreementen
dc.rightsIntellectual Property Guidelines at Queen's Universityen
dc.rightsCopying and Preserving Your Thesisen
dc.rightsThis publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.en
dc.subjectCa2+ Sensoren
dc.subjectArabidopsisen
dc.subjectCML15en
dc.subjectCa2+ signalingen
dc.subjectCML16en
dc.titleAn Investigation of the Biochemical Properties and Physiological Roles of the Arabidopsis Calmodulin-Like (CML) Genes CML15 and CML16en
dc.typethesisen
dc.description.restricted-thesisWe are looking to publish the data in this thesis in the near future. Consequently, we do not want it to be available to the public before this occurs.en
dc.description.degreeM.Sc.en
dc.contributor.supervisorSnedden, Wayne A.en
dc.contributor.departmentBiologyen
dc.embargo.terms1825en
dc.embargo.liftdate2021-01-12
dc.degree.grantorQueen's University at Kingstonen


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