Expression of cDNA clones of the M1 double-stranded RNA killer preprotoxin coding region in Saccharomyces cerevisiae successfully directed the synthesis of secreted active toxin. Transformants harbouring these expression plasmids also displayed a K1 specific immunity phenotype. Immunoprecipitation of intracellular proteins with antitoxin antiserum showed that these transformants synthesize a 42kd glycosylated preprotoxin precursor. Two smaller unglycosylated immunoreactive species could also be resolved. These toxin precursor species were characterized by using secretory-defective hosts, by comparative electrophoretic mobilities, and by tunicamycin susceptibility. Such studies indicate that these protein species represent intermediates generated by signal cleavage of the preprotoxin and its subsequent glycosylation and provide evidence that these events occur post-translationally. Mutational analysis of the 44 amino acid preprotoxin N-terminal leader indicated that it is functionally bipartite, consisting of an N-terminal signal sequence and a C-terminal pro-sequence. Deletion of the leader perturbed but did not eliminate secretion of toxin.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.75435 |
| Date | January 1987 |
| Creators | Lolle, Susan Janne |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Biology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 000554134, proquestno: AAINL44310, Theses scanned by UMI/ProQuest. |
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