| title: | Elaboration of new microbial systems for the expression of foreign proteins¿¿¿¿¿ |
|---|---|
| reg no: | ETF5676 |
| project type: | Estonian Science Foundation research grant |
| subject: |
1.9. Genetics, Physiology and Microbiology 2.7. Biotechnology, Food and Drink Technology |
| status: | accepted |
| institution: | TU Faculty of Biology and Geography |
| head of project: | Tiina Alamäe |
| duration: | 01.01.2004 - 31.12.2007 |
| description: | The aim of the present grant proposal is to study different yeast strains (mainly methylotrophic Hansenula polymorpha) and their promoters to elaborate novel expression systems of heterologous proteins. Methylotrophic yeasts (Hansenula polymorpha, Pichia pastoris) are actively used as a host in biotechnology to produce recombinant enzymes, vaccines (against hepatitis B) and other products (hirudin, phytase). Mostly strong methanol-regulated promoters (alcohol oxidase promoter) are used to drive the expression of a foreign gene. We have described the H. polymorpha maltase gene promoter that is biotechnologically highly attractive: it has perfect expression in not only in yeasts (Hansenula and S. cerevisiae) but also in E. coli. We will carry out a detailed study of the maltase promoter in order to evaluate and optimize its application in the expression cassettes for the production of biotechnological products of interest in yeasts and in bacteria. Expression of the promoter in different wild-type and mutant strains will be studied. The performance of the maltase promoter will be compared to that of the alcohol oxidase, TEF and hexokinase promoters. We will design the wide host-range expression plasmid that can replicate in three different hosts: H. polymorpha, S. cerevisiae and E. coli using the maltase gene promoter as a transcription controlling element. The role of sugar kinases in glucose repression signaling in H. polymorpha studied using expression of heterologous hexokinases in H. polymorpha double kinase-negative mutant and study of the sugar repression phenotype of the transformants. The homologue of the S. cerevisiae MIG1 gene (a key mediator of glucose repression) will be disrupted in H. polymorpha in order to genenerate a attractive host for the expression of heterlogous proteins from the glucose-repressed promoters. |
| project group | ||||
|---|---|---|---|---|
| no | name | institution | position | |
| 1. | Tiina Alamäe | TU Faculty of Biology and Geography | Docent | |
| 2. | Helen Karp | MRI | ||
| 3. | Katrin Viigand | MRI | ||