{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/87239"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/87239","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"The Calcium Channel Gamma6 Subunit Analysis of Function and Determination of a Sequence Motif Critical for Its Effect","abstract":"The auxiliary gamma6 subunit of voltage dependent calcium channels is known to decrease calcium current density when co-expressed with the pore forming Cav3.1 subunit. In this study, I showed that Cav3.1 calcium channels are a major pathway for calcium influx at resting membrane potential, and that the gamma6 subunit is a modulator of this LVA window current in HEK-Cav3.1 cells by employing a calcium imaging technique. Further, I demonstrated that co-expression of gamma6 subunit decreases Cav2.3 dependent calcium current density. Previous studies using chimeric gamma subunits indicate that the N-terminal region, including the first transmembrane domain (TM1), is critical for the inhibitory function of the gamma6 subunit. In this study, I have investigated the functional properties of the gamma6 TM1 and identified critical motifs and residues in this region. Calcium current density in HEK-Cav3.1 cells was monitored following transfection with plasmids containing either gamma 6 TM1 or various mutants of this peptide. The gamma6 TM1 significantly inhibits the expression of Cav3.1 current suggesting that gamma 6 TM1 is both necessary and sufficient to inhibit Cav3.1 calcium current. Co-immunoprecipitation experiments indicate the presence of a gamma 6/alpha1 subunit complex when the two proteins are co-expressed. We identified two adjacent GxxxA motifs (G42xxxA46xxG 49xxxA53) in the gamma6 TM1 which are predicted to produce a long groove on one face of the helix due to the short side chains of the glycine and alanine residues. GxxxA and related motifs are thought to be important for promoting and stabilizing helix-helix interactions. Therefore we performed site directed mutagenesis of these specific residues in TM1 replacing the G and A residues with amino acids containing large side chains. The G42L and A46I mutants are no longer inhibitory while the G49L mutant retained the inhibitory function of the wild type. Our results suggest that the first GxxxA motif within TM1 of gamma6 is critical for its ability to inhibit Cav3.1 calcium current. Overall, my study enhances our understanding of the function and structure of the gamma6 subunit, and provides a basic approach to design novel therapeutic agents to target calcium channels.","abstract_html":"The auxiliary gamma6 subunit of voltage dependent calcium channels is known to decrease calcium current density when co-expressed with the pore forming Cav3.1 subunit. In this study, I showed that Cav3.1 calcium channels are a major pathway for calcium influx at resting membrane potential, and that the gamma6 subunit is a modulator of this LVA window current in HEK-Cav3.1 cells by employing a calcium imaging technique. Further, I demonstrated that co-expression of gamma6 subunit decreases Cav2.3 dependent calcium current density. Previous studies using chimeric gamma subunits indicate that the N-terminal region, including the first transmembrane domain (TM1), is critical for the inhibitory function of the gamma6 subunit. In this study, I have investigated the functional properties of the gamma6 TM1 and identified critical motifs and residues in this region. Calcium current density in HEK-Cav3.1 cells was monitored following transfection with plasmids containing either gamma 6 TM1 or various mutants of this peptide. The gamma6 TM1 significantly inhibits the expression of Cav3.1 current suggesting that gamma 6 TM1 is both necessary and sufficient to inhibit Cav3.1 calcium current. Co-immunoprecipitation experiments indicate the presence of a gamma 6/alpha1 subunit complex when the two proteins are co-expressed. We identified two adjacent GxxxA motifs (G42xxxA46xxG 49xxxA53) in the gamma6 TM1 which are predicted to produce a long groove on one face of the helix due to the short side chains of the glycine and alanine residues. GxxxA and related motifs are thought to be important for promoting and stabilizing helix-helix interactions. Therefore we performed site directed mutagenesis of these specific residues in TM1 replacing the G and A residues with amino acids containing large side chains. The G42L and A46I mutants are no longer inhibitory while the G49L mutant retained the inhibitory function of the wild type. Our results suggest that the first GxxxA motif within TM1 of gamma6 is critical for its ability to inhibit Cav3.1 calcium current. Overall, my study enhances our understanding of the function and structure of the gamma6 subunit, and provides a basic approach to design novel therapeutic agents to target calcium channels.","abstract_has_math":false,"creators":["Lin, Zuojun"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Molecular and Integrative Physiology","degree_department":null,"school":null,"contributors":["Philip Best"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-09-28T15:50:11Z","date_published":"2015-09-28T15:50:11Z","updated_at":"2026-07-22T22:26:28Z","subjects":["Biophysics, General"],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(MiAaPQ)AAI3202130"],"render_values":[{"text":"(MiAaPQ)AAI3202130","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/87239","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Philip Best"]},{"key":"dc:creator","label":"Author","values":["Lin, Zuojun"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2015-09-28T15:50:11Z","10000-01-01","2005"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Molecular and Integrative Physiology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Biophysics, General"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/87239","(MiAaPQ)AAI3202130"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The auxiliary gamma6 subunit of voltage dependent calcium channels is known to decrease calcium current density when co-expressed with the pore forming Cav3.1 subunit. In this study, I showed that Cav3.1 calcium channels are a major pathway for calcium influx at resting membrane potential, and that the gamma6 subunit is a modulator of this LVA window current in HEK-Cav3.1 cells by employing a calcium imaging technique. Further, I demonstrated that co-expression of gamma6 subunit decreases Cav2.3 dependent calcium current density. Previous studies using chimeric gamma subunits indicate that the N-terminal region, including the first transmembrane domain (TM1), is critical for the inhibitory function of the gamma6 subunit. In this study, I have investigated the functional properties of the gamma6 TM1 and identified critical motifs and residues in this region. Calcium current density in HEK-Cav3.1 cells was monitored following transfection with plasmids containing either gamma 6 TM1 or various mutants of this peptide. The gamma6 TM1 significantly inhibits the expression of Cav3.1 current suggesting that gamma 6 TM1 is both necessary and sufficient to inhibit Cav3.1 calcium current. Co-immunoprecipitation experiments indicate the presence of a gamma 6/alpha1 subunit complex when the two proteins are co-expressed. We identified two adjacent GxxxA motifs (G42xxxA46xxG 49xxxA53) in the gamma6 TM1 which are predicted to produce a long groove on one face of the helix due to the short side chains of the glycine and alanine residues. GxxxA and related motifs are thought to be important for promoting and stabilizing helix-helix interactions. Therefore we performed site directed mutagenesis of these specific residues in TM1 replacing the G and A residues with amino acids containing large side chains. The G42L and A46I mutants are no longer inhibitory while the G49L mutant retained the inhibitory function of the wild type. Our results suggest that the first GxxxA motif within TM1 of gamma6 is critical for its ability to inhibit Cav3.1 calcium current. Overall, my study enhances our understanding of the function and structure of the gamma6 subunit, and provides a basic approach to design novel therapeutic agents to target calcium channels.","Made available in DSpace on 2015-09-28T15:50:11Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 3202130.pdf: 2077116 bytes, checksum: 31a94daf26818a29e3361f4ed5a4df45 (MD5) Previous issue date: 2005","Embargo set by: Seth Robbins for item 88520 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","106 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2005."]},{"key":"dc:title","label":"Title","values":["The Calcium Channel Gamma6 Subunit Analysis of Function and Determination of a Sequence Motif Critical for Its Effect"]}]}],"canonical_facts":{"dc:contributor":["Philip Best"],"dc:creator":["Lin, Zuojun"],"dc:date":["2015-09-28T15:50:11Z","10000-01-01","2005"],"dc:description":["The auxiliary gamma6 subunit of voltage dependent calcium channels is known to decrease calcium current density when co-expressed with the pore forming Cav3.1 subunit. In this study, I showed that Cav3.1 calcium channels are a major pathway for calcium influx at resting membrane potential, and that the gamma6 subunit is a modulator of this LVA window current in HEK-Cav3.1 cells by employing a calcium imaging technique. Further, I demonstrated that co-expression of gamma6 subunit decreases Cav2.3 dependent calcium current density. Previous studies using chimeric gamma subunits indicate that the N-terminal region, including the first transmembrane domain (TM1), is critical for the inhibitory function of the gamma6 subunit. In this study, I have investigated the functional properties of the gamma6 TM1 and identified critical motifs and residues in this region. Calcium current density in HEK-Cav3.1 cells was monitored following transfection with plasmids containing either gamma 6 TM1 or various mutants of this peptide. The gamma6 TM1 significantly inhibits the expression of Cav3.1 current suggesting that gamma 6 TM1 is both necessary and sufficient to inhibit Cav3.1 calcium current. Co-immunoprecipitation experiments indicate the presence of a gamma 6/alpha1 subunit complex when the two proteins are co-expressed. We identified two adjacent GxxxA motifs (G42xxxA46xxG 49xxxA53) in the gamma6 TM1 which are predicted to produce a long groove on one face of the helix due to the short side chains of the glycine and alanine residues. GxxxA and related motifs are thought to be important for promoting and stabilizing helix-helix interactions. Therefore we performed site directed mutagenesis of these specific residues in TM1 replacing the G and A residues with amino acids containing large side chains. The G42L and A46I mutants are no longer inhibitory while the G49L mutant retained the inhibitory function of the wild type. Our results suggest that the first GxxxA motif within TM1 of gamma6 is critical for its ability to inhibit Cav3.1 calcium current. Overall, my study enhances our understanding of the function and structure of the gamma6 subunit, and provides a basic approach to design novel therapeutic agents to target calcium channels.","Made available in DSpace on 2015-09-28T15:50:11Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 3202130.pdf: 2077116 bytes, checksum: 31a94daf26818a29e3361f4ed5a4df45 (MD5) Previous issue date: 2005","Embargo set by: Seth Robbins for item 88520 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","106 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2005."],"dc:identifier":["http://hdl.handle.net/2142/87239","(MiAaPQ)AAI3202130"],"dc:language":["eng"],"dc:subject":["Biophysics, General"],"dc:title":["The Calcium Channel Gamma6 Subunit Analysis of Function and Determination of a Sequence Motif Critical for Its Effect"],"dc:type":["text"],"thesis:degree_discipline":["Molecular and Integrative Physiology"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:26:28Z"}