{"id":{"repo_id":"toronto-retro","oai_identifier":"oai:utoronto.scholaris.ca:1807/42519"},"canonical_url":"https://search.dev.ndltd.org/etd/toronto-retro/oai:utoronto.scholaris.ca:1807/42519","repository":{"repo_id":"toronto-retro","name":"University of Toronto","base_url":"https://utoronto.scholaris.ca/server/oai/request"},"display":{"title":"The Characterization of Nemadipine and Migrazole as Small Molecule Tools for Use in the Nematode Caenorhabditis elegans","abstract":"Small molecules are powerful reagents for biological investigation. They provide an alternative to genetic perturbation and may offer more control over a target’s activity. C. elegans has recently gained prominence as a platform to discover new chemical tools. Through large-scale screens for compounds that induce phenotypes consistent with the disruption of conserved pathways, we identified two previously uncharacterized molecules of interest that we named nemadipine and migrazole. Here, I describe my efforts to understand their mechanism of action. Nemadipine is structurally analogous to 1,4-dihydropyridines (DHPs), which target the Cav1 calcium channel and are used clinically to lower blood pressure. Phenotypic and genetic evidence suggest that nemadipine targets the worm Cav1 channel, EGL-19. To identify the target of nemadipine in an unbiased manner, I performed a forward genetic screen for mutants resistant to its effects. The majority of the mutants from my screen had polymorphisms in EGL-19, providing additional evidence that it is the target of nemadipine. I also found that nemadipine is the only DHP that robustly elicits phenotypes in the worm. Therefore, I used this unique chemical to investigate the in vivo interactions between DHPs and the Cav1 channel. I identified residues in EGL-19 important for DHP-sensitivity in worms and showed that some of these residues are also important for mammalian DHP-interaction. Other labs have since exploited nemadipine’s in vivo properties to demonstrate new biological insights for EGL-19. Chemical genetic analyses indicated that migrazole disrupts multiple signal transduction pathways. This, together with experiments that I performed in yeast, suggests that migrazole may affect multiple pathways by perturbation of protein transport. To identify migrazole’s target, I performed a forward genetic screen for mutants resistant to migrazole’s effects. However, I was unable to identify the target of migrazole through analysis of the mutants I isolated. This result illustrates that while forward genetic screens can be very successful for target identification, their effectiveness is likely dependent on the nature of the compound-target interaction. My work shows that all aspects of developing a small molecule into a tool for biological analysis, from its discovery to its characterization, can be accomplished using C. elegans.","abstract_html":"Small molecules are powerful reagents for biological investigation. They provide an alternative to genetic perturbation and may offer more control over a target’s activity. C. elegans has recently gained prominence as a platform to discover new chemical tools. Through large-scale screens for compounds that induce phenotypes consistent with the disruption of conserved pathways, we identified two previously uncharacterized molecules of interest that we named nemadipine and migrazole. Here, I describe my efforts to understand their mechanism of action. Nemadipine is structurally analogous to 1,4-dihydropyridines (DHPs), which target the Cav1 calcium channel and are used clinically to lower blood pressure. Phenotypic and genetic evidence suggest that nemadipine targets the worm Cav1 channel, EGL-19. To identify the target of nemadipine in an unbiased manner, I performed a forward genetic screen for mutants resistant to its effects. The majority of the mutants from my screen had polymorphisms in EGL-19, providing additional evidence that it is the target of nemadipine. I also found that nemadipine is the only DHP that robustly elicits phenotypes in the worm. Therefore, I used this unique chemical to investigate the in vivo interactions between DHPs and the Cav1 channel. I identified residues in EGL-19 important for DHP-sensitivity in worms and showed that some of these residues are also important for mammalian DHP-interaction. Other labs have since exploited nemadipine’s in vivo properties to demonstrate new biological insights for EGL-19. Chemical genetic analyses indicated that migrazole disrupts multiple signal transduction pathways. This, together with experiments that I performed in yeast, suggests that migrazole may affect multiple pathways by perturbation of protein transport. To identify migrazole’s target, I performed a forward genetic screen for mutants resistant to migrazole’s effects. However, I was unable to identify the target of migrazole through analysis of the mutants I isolated. This result illustrates that while forward genetic screens can be very successful for target identification, their effectiveness is likely dependent on the nature of the compound-target interaction. My work shows that all aspects of developing a small molecule into a tool for biological analysis, from its discovery to its characterization, can be accomplished using C. elegans.","abstract_has_math":false,"creators":["Kwok, Trevor"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":"Molecular and Medical Genetics","school":null,"contributors":[],"advisors":["Roy, Peter John"],"committee_chairs":[],"committee_members":[],"year":2012,"date_issued":"2012-03","date_published":"2012-03","updated_at":"2026-07-27T21:28:09Z","subjects":["small molecules","C. elegans","nemadipine","migrazole"],"languages":["en_ca"],"rights":["Attribution 3.0 Unported"],"rights_urls":["http://creativecommons.org/licenses/by/3.0/"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/1807/42519","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Roy, Peter John"]},{"key":"dc:contributor.department","label":"Department","values":["Molecular and Medical Genetics"]},{"key":"dc:creator","label":"Author","values":["Kwok, Trevor"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2012-03"]},{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2013-11-19T18:12:16Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["WITHHELD_ONE_YEAR","2013-11-19T18:12:16Z"]},{"key":"dc:date.issued","label":"Date","values":["2012-03"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["small molecules","C. elegans","nemadipine","migrazole"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en_ca"]},{"key":"dc:rights","label":"Dc Rights","values":["Attribution 3.0 Unported"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://creativecommons.org/licenses/by/3.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/1807/42519"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Small molecules are powerful reagents for biological investigation. They provide an alternative to genetic perturbation and may offer more control over a target’s activity. C. elegans has recently gained prominence as a platform to discover new chemical tools. Through large-scale screens for compounds that induce phenotypes consistent with the disruption of conserved pathways, we identified two previously uncharacterized molecules of interest that we named nemadipine and migrazole. Here, I describe my efforts to understand their mechanism of action. Nemadipine is structurally analogous to 1,4-dihydropyridines (DHPs), which target the Cav1 calcium channel and are used clinically to lower blood pressure. Phenotypic and genetic evidence suggest that nemadipine targets the worm Cav1 channel, EGL-19. To identify the target of nemadipine in an unbiased manner, I performed a forward genetic screen for mutants resistant to its effects. The majority of the mutants from my screen had polymorphisms in EGL-19, providing additional evidence that it is the target of nemadipine. I also found that nemadipine is the only DHP that robustly elicits phenotypes in the worm. Therefore, I used this unique chemical to investigate the in vivo interactions between DHPs and the Cav1 channel. I identified residues in EGL-19 important for DHP-sensitivity in worms and showed that some of these residues are also important for mammalian DHP-interaction. Other labs have since exploited nemadipine’s in vivo properties to demonstrate new biological insights for EGL-19. Chemical genetic analyses indicated that migrazole disrupts multiple signal transduction pathways. This, together with experiments that I performed in yeast, suggests that migrazole may affect multiple pathways by perturbation of protein transport. To identify migrazole’s target, I performed a forward genetic screen for mutants resistant to migrazole’s effects. However, I was unable to identify the target of migrazole through analysis of the mutants I isolated. This result illustrates that while forward genetic screens can be very successful for target identification, their effectiveness is likely dependent on the nature of the compound-target interaction. My work shows that all aspects of developing a small molecule into a tool for biological analysis, from its discovery to its characterization, can be accomplished using C. elegans."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["PhD"]},{"key":"dc:title","label":"Title","values":["The Characterization of Nemadipine and Migrazole as Small Molecule Tools for Use in the Nematode Caenorhabditis elegans"]}]}],"canonical_facts":{"dc:contributor.advisor":["Roy, Peter John"],"dc:contributor.department":["Molecular and Medical Genetics"],"dc:creator":["Kwok, Trevor"],"dc:date":["2012-03"],"dc:date.accessioned":["2013-11-19T18:12:16Z"],"dc:date.available":["WITHHELD_ONE_YEAR","2013-11-19T18:12:16Z"],"dc:date.issued":["2012-03"],"dc:description.abstract":["Small molecules are powerful reagents for biological investigation. They provide an alternative to genetic perturbation and may offer more control over a target’s activity. C. elegans has recently gained prominence as a platform to discover new chemical tools. Through large-scale screens for compounds that induce phenotypes consistent with the disruption of conserved pathways, we identified two previously uncharacterized molecules of interest that we named nemadipine and migrazole. Here, I describe my efforts to understand their mechanism of action. Nemadipine is structurally analogous to 1,4-dihydropyridines (DHPs), which target the Cav1 calcium channel and are used clinically to lower blood pressure. Phenotypic and genetic evidence suggest that nemadipine targets the worm Cav1 channel, EGL-19. To identify the target of nemadipine in an unbiased manner, I performed a forward genetic screen for mutants resistant to its effects. The majority of the mutants from my screen had polymorphisms in EGL-19, providing additional evidence that it is the target of nemadipine. I also found that nemadipine is the only DHP that robustly elicits phenotypes in the worm. Therefore, I used this unique chemical to investigate the in vivo interactions between DHPs and the Cav1 channel. I identified residues in EGL-19 important for DHP-sensitivity in worms and showed that some of these residues are also important for mammalian DHP-interaction. Other labs have since exploited nemadipine’s in vivo properties to demonstrate new biological insights for EGL-19. Chemical genetic analyses indicated that migrazole disrupts multiple signal transduction pathways. This, together with experiments that I performed in yeast, suggests that migrazole may affect multiple pathways by perturbation of protein transport. To identify migrazole’s target, I performed a forward genetic screen for mutants resistant to migrazole’s effects. However, I was unable to identify the target of migrazole through analysis of the mutants I isolated. This result illustrates that while forward genetic screens can be very successful for target identification, their effectiveness is likely dependent on the nature of the compound-target interaction. My work shows that all aspects of developing a small molecule into a tool for biological analysis, from its discovery to its characterization, can be accomplished using C. elegans."],"dc:description.degree":["PhD"],"dc:identifier.uri":["http://hdl.handle.net/1807/42519"],"dc:language.iso":["en_ca"],"dc:rights":["Attribution 3.0 Unported"],"dc:rights.uri":["http://creativecommons.org/licenses/by/3.0/"],"dc:subject":["small molecules","C. elegans","nemadipine","migrazole"],"dc:title":["The Characterization of Nemadipine and Migrazole as Small Molecule Tools for Use in the Nematode Caenorhabditis elegans"],"dc:type":["Thesis"]},"updated_at":"2026-07-27T21:28:09Z"}