{"id":{"repo_id":"denver","oai_identifier":"oai:digitalcommons.du.edu:etd-3208"},"canonical_url":"https://search.dev.ndltd.org/etd/denver/oai:digitalcommons.du.edu:etd-3208","repository":{"repo_id":"denver","name":"University of Denver","base_url":"https://digitalcommons.du.edu/do/oai/"},"display":{"title":"Developing Red Fluorescent Zn2+ Sensors and Characterizing Zn2+ Homeostasis in Mucolipidosis Type IV Disease","abstract":"<p>Zinc (Zn<sup>2+</sup>) is a divalent, redox-inert metal that plays a vital role in many cellular processes either by acting as a catalytic cofactor or a labile signaling molecule in the cytoplasm. Cytosolic Zn<sup>2+</sup> levels are tightly regulated to stay within a narrow window of concentrations, but fluctuations in Zn<sup>2+</sup> signals have been detected in a variety of cells. We developed a genetically encoded, single red fluorescent protein (RFP) based Zn<sup>2+</sup> sensor, RZnP1, that can be used alongside green-wavelength sensors for the simultaneous detection of different signaling molecules within the same cells or among different subcellular compartments. The excitation wavelength of many RFPs is less phototoxic than that of GFPs which extends imaging time. We demonstrate live cell multi-compartmental imaging of cytosolic and mitochondrial Zn<sup>2+</sup> dynamics using RZnP1 and mitochondria targeted GZnP2 and discovered that high concentrations of cytosolic Zn<sup>2+</sup> are not sequestered into mitochondria in healthy neurons.</p> <p>My second project aims to study Zn<sup>2+</sup> homeostasis in Mucolipidosis type IV (MLIV). MLIV is an inherited neurodevelopmental and neurodegenerative disorder, which has severe developmental delay, psychomotor deficits, and vision loss. It is caused by loss-function mutations in the lysosomal channel TRPML1. We assess the Zn<sup>2+</sup> and Ca<sup>2+</sup> permeability and localization of 10 different TRPML1 patient mutants. Furthermore, we quantify Zn<sup>2+</sup> concentrations in the cytosol, lysosomes, and mitochondria in MLIV patient fibroblasts. We found that mitochondrial Zn<sup>2+</sup> concentrations are significantly higher in MLIV cells. Next, we demonstrate that high lysosomal Zn<sup>2+</sup> can be imported into the mitochondria. Lastly, we assessed whether higher mitochondrial Zn<sup>2+</sup> in MLIV cells can affect mitochondrial morphology.</p>","abstract_html":"&lt;p&gt;Zinc (Zn&lt;sup&gt;2+&lt;/sup&gt;) is a divalent, redox-inert metal that plays a vital role in many cellular processes either by acting as a catalytic cofactor or a labile signaling molecule in the cytoplasm. Cytosolic Zn&lt;sup&gt;2+&lt;/sup&gt; levels are tightly regulated to stay within a narrow window of concentrations, but fluctuations in Zn&lt;sup&gt;2+&lt;/sup&gt; signals have been detected in a variety of cells. We developed a genetically encoded, single red fluorescent protein (RFP) based Zn&lt;sup&gt;2+&lt;/sup&gt; sensor, RZnP1, that can be used alongside green-wavelength sensors for the simultaneous detection of different signaling molecules within the same cells or among different subcellular compartments. The excitation wavelength of many RFPs is less phototoxic than that of GFPs which extends imaging time. We demonstrate live cell multi-compartmental imaging of cytosolic and mitochondrial Zn&lt;sup&gt;2+&lt;/sup&gt; dynamics using RZnP1 and mitochondria targeted GZnP2 and discovered that high concentrations of cytosolic Zn&lt;sup&gt;2+&lt;/sup&gt; are not sequestered into mitochondria in healthy neurons.&lt;/p&gt; &lt;p&gt;My second project aims to study Zn&lt;sup&gt;2+&lt;/sup&gt; homeostasis in Mucolipidosis type IV (MLIV). MLIV is an inherited neurodevelopmental and neurodegenerative disorder, which has severe developmental delay, psychomotor deficits, and vision loss. It is caused by loss-function mutations in the lysosomal channel TRPML1. We assess the Zn&lt;sup&gt;2+&lt;/sup&gt; and Ca&lt;sup&gt;2+&lt;/sup&gt; permeability and localization of 10 different TRPML1 patient mutants. Furthermore, we quantify Zn&lt;sup&gt;2+&lt;/sup&gt; concentrations in the cytosol, lysosomes, and mitochondria in MLIV patient fibroblasts. We found that mitochondrial Zn&lt;sup&gt;2+&lt;/sup&gt; concentrations are significantly higher in MLIV cells. Next, we demonstrate that high lysosomal Zn&lt;sup&gt;2+&lt;/sup&gt; can be imported into the mitochondria. Lastly, we assessed whether higher mitochondrial Zn&lt;sup&gt;2+&lt;/sup&gt; in MLIV cells can affect mitochondrial morphology.&lt;/p&gt;","abstract_has_math":false,"creators":["Dischler, Anna M."],"institution":null,"degree_name":"M.S.","degree_level":"Masters Thesis","degree_discipline":null,"degree_department":null,"school":null,"contributors":["Yan Qin","Martin Margittai","Scott Barbee","Dan Linseman"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2023,"date_issued":"2023-01-01T08:00:00Z","date_published":"2023-01-01T08:00:00Z","updated_at":"2026-07-24T02:02:38Z","subjects":["Fluorescence","Lysosomes","Mucolipidosis","Neurodegenerative","Zinc","Biochemistry, Biophysics, and Structural Biology","Cell and Developmental Biology","Cell Biology","Life Sciences","Molecular Biology"],"languages":["en"],"rights":["<p>Copyright is held by the author. User is responsible for all copyright compliance.</p>"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://digitalcommons.du.edu/etd/2220","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Yan Qin","Martin Margittai","Scott Barbee","Dan Linseman"]},{"key":"dc:creator","label":"Author","values":["Dischler, Anna M."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2025-08-01T07:00:00Z"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Masters Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Fluorescence","Lysosomes","Mucolipidosis","Neurodegenerative","Zinc","Biochemistry, Biophysics, and Structural Biology","Cell and Developmental Biology","Cell Biology","Life Sciences","Molecular Biology"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["<p>Copyright is held by the author. User is responsible for all copyright compliance.</p>"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://digitalcommons.du.edu/etd/2220"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["<p>Zinc (Zn<sup>2+</sup>) is a divalent, redox-inert metal that plays a vital role in many cellular processes either by acting as a catalytic cofactor or a labile signaling molecule in the cytoplasm. Cytosolic Zn<sup>2+</sup> levels are tightly regulated to stay within a narrow window of concentrations, but fluctuations in Zn<sup>2+</sup> signals have been detected in a variety of cells. We developed a genetically encoded, single red fluorescent protein (RFP) based Zn<sup>2+</sup> sensor, RZnP1, that can be used alongside green-wavelength sensors for the simultaneous detection of different signaling molecules within the same cells or among different subcellular compartments. The excitation wavelength of many RFPs is less phototoxic than that of GFPs which extends imaging time. We demonstrate live cell multi-compartmental imaging of cytosolic and mitochondrial Zn<sup>2+</sup> dynamics using RZnP1 and mitochondria targeted GZnP2 and discovered that high concentrations of cytosolic Zn<sup>2+</sup> are not sequestered into mitochondria in healthy neurons.</p> <p>My second project aims to study Zn<sup>2+</sup> homeostasis in Mucolipidosis type IV (MLIV). MLIV is an inherited neurodevelopmental and neurodegenerative disorder, which has severe developmental delay, psychomotor deficits, and vision loss. It is caused by loss-function mutations in the lysosomal channel TRPML1. We assess the Zn<sup>2+</sup> and Ca<sup>2+</sup> permeability and localization of 10 different TRPML1 patient mutants. Furthermore, we quantify Zn<sup>2+</sup> concentrations in the cytosol, lysosomes, and mitochondria in MLIV patient fibroblasts. We found that mitochondrial Zn<sup>2+</sup> concentrations are significantly higher in MLIV cells. Next, we demonstrate that high lysosomal Zn<sup>2+</sup> can be imported into the mitochondria. Lastly, we assessed whether higher mitochondrial Zn<sup>2+</sup> in MLIV cells can affect mitochondrial morphology.</p>"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Developing Red Fluorescent Zn2+ Sensors and Characterizing Zn2+ Homeostasis in Mucolipidosis Type IV Disease"]}]}],"canonical_facts":{"dc:contributor":["Yan Qin","Martin Margittai","Scott Barbee","Dan Linseman"],"dc:creator":["Dischler, Anna M."],"dc:date.available":["2025-08-01T07:00:00Z"],"dc:description.abstract":["<p>Zinc (Zn<sup>2+</sup>) is a divalent, redox-inert metal that plays a vital role in many cellular processes either by acting as a catalytic cofactor or a labile signaling molecule in the cytoplasm. Cytosolic Zn<sup>2+</sup> levels are tightly regulated to stay within a narrow window of concentrations, but fluctuations in Zn<sup>2+</sup> signals have been detected in a variety of cells. We developed a genetically encoded, single red fluorescent protein (RFP) based Zn<sup>2+</sup> sensor, RZnP1, that can be used alongside green-wavelength sensors for the simultaneous detection of different signaling molecules within the same cells or among different subcellular compartments. The excitation wavelength of many RFPs is less phototoxic than that of GFPs which extends imaging time. We demonstrate live cell multi-compartmental imaging of cytosolic and mitochondrial Zn<sup>2+</sup> dynamics using RZnP1 and mitochondria targeted GZnP2 and discovered that high concentrations of cytosolic Zn<sup>2+</sup> are not sequestered into mitochondria in healthy neurons.</p> <p>My second project aims to study Zn<sup>2+</sup> homeostasis in Mucolipidosis type IV (MLIV). MLIV is an inherited neurodevelopmental and neurodegenerative disorder, which has severe developmental delay, psychomotor deficits, and vision loss. It is caused by loss-function mutations in the lysosomal channel TRPML1. We assess the Zn<sup>2+</sup> and Ca<sup>2+</sup> permeability and localization of 10 different TRPML1 patient mutants. Furthermore, we quantify Zn<sup>2+</sup> concentrations in the cytosol, lysosomes, and mitochondria in MLIV patient fibroblasts. We found that mitochondrial Zn<sup>2+</sup> concentrations are significantly higher in MLIV cells. Next, we demonstrate that high lysosomal Zn<sup>2+</sup> can be imported into the mitochondria. Lastly, we assessed whether higher mitochondrial Zn<sup>2+</sup> in MLIV cells can affect mitochondrial morphology.</p>"],"dc:format":["application/pdf"],"dc:identifier":["https://digitalcommons.du.edu/etd/2220"],"dc:language":["en"],"dc:rights":["<p>Copyright is held by the author. User is responsible for all copyright compliance.</p>"],"dc:subject":["Fluorescence","Lysosomes","Mucolipidosis","Neurodegenerative","Zinc","Biochemistry, Biophysics, and Structural Biology","Cell and Developmental Biology","Cell Biology","Life Sciences","Molecular Biology"],"dc:title":["Developing Red Fluorescent Zn2+ Sensors and Characterizing Zn2+ Homeostasis in Mucolipidosis Type IV Disease"],"thesis:degree_level":["Masters Thesis"],"thesis:degree_name":["M.S."]},"updated_at":"2026-07-24T02:02:38Z"}