Molecular characterization of GABA receptor subunits from the parasitic nematode Haemonchus contortus
| dc.contributor.advisor | Forrester, Sean | |
| dc.contributor.advisor | Bonetta, Dario | |
| dc.contributor.author | Siddiqui, Salma | |
| dc.date.accessioned | 2009-10-09T19:17:30Z | |
| dc.date.accessioned | 2022-03-29T17:06:26Z | |
| dc.date.available | 2009-10-09T19:17:30Z | |
| dc.date.available | 2022-03-29T17:06:26Z | |
| dc.date.issued | 2009-08-01 | |
| dc.degree.discipline | Applied Bioscience | en |
| dc.degree.level | Master of Science (MSc) | en |
| dc.description.abstract | Haemonchus contortus is a parasitic nematode that is controlled by several nematocides which target ion channels. We have identified two H. contortus ion channel genes, Hcounc- 49B and C that encode two GABA-gated chloride channel subunits. Electrophysiological analysis shows that the Hco-UNC-49B subunit forms a functional homomeric channel in Xenopus laevis oocytes that produces a robust response to GABA and is highly sensitive to picrotoxin. In contrast, Hco-UNC-49C alone does not respond to GABA but can assemble with Hco-UNC-49B to form a heteromeric channel with an increased sensitivity to GABA and a lower sensitivity to picrotoxin. To investigate the subunit requirements for high agonist sensitivity, we generated cross-assembled channels by co-expressing the H. contortus subunits with UNC-49 subunits from the nematode Caenorhabditis elegans (Cel-UNC-49). Co-expressing the Cel-UNC-49B with Hco- UNC-49C produced a heteromeric channel with a low sensitivity to GABA. In contrast, co-expressing Hco-UNC-49B with Cel-UNC-49C produced a heteromeric channel that was highly sensitive to GABA. These results suggest that the Hco-UNC-49B subunit is the key determinant for the high agonist sensitivity of heteromeric channels. | en |
| dc.description.sponsorship | University of Ontario Institute of Technology | en |
| dc.identifier.uri | https://hdl.handle.net/10155/31 | |
| dc.language.iso | en | en |
| dc.subject | GABA | en |
| dc.subject | Ligand-gated chloride channel | en |
| dc.subject | Electrophysiology | en |
| dc.subject | Homomeric channel | en |
| dc.subject | Haemonchus contortus | en |
| dc.subject | Heteromeric channel | en |
| dc.title | Molecular characterization of GABA receptor subunits from the parasitic nematode Haemonchus contortus | en |
| dc.type | Thesis | en |