Objetivo
Microbial systems are particularly suited for the production of recombinant proteins. Among them yeasts have often been successful where bacterial systems failed. Whilst many attempts have been made with the classical baker's yeast Saccharomyces cerevisiae, the most significant achievements in the production of mammalian proteins have been obtained by the use of a few non-Saccharomyces yeasts. Especially, the dairy yeast Kluyveromyces lactis has been shown to be capable of grams-perlitre scale production. The particularity of this proposal is to exploit the natural genetic reservoir present in the large variety of yeast species. Two approaches are taken:
(1) Model systems.
Two established systems to which advanced genetic analysis can be applied, namely, Kluyveromyces lactis and Yarrowia lipolytica, will be used to examine the host parameters that determine the performance of protein production. At present, the control of host conditions, rather than further manipulation of individual gene expression cassettes, is considered to be determinant to improve the production process. The host parameters concern the provision of substrates (carbon and energy metabolism), the protein synthesising process itself (transcription and translation) and the product sorting (protein traffic and secretion).
These parameters will be examined under the stress conditions created by the forced synthesis of heterologous proteins. The proposal will include extensive fermentor-level studies. The project is expected to strengthen the leading position of the EC in this field established through the successive biotehnology programmes.
(2) Development of new hosts and novel genetic resources.
Parallel to the studies on model organismes, new host systems will be explored in two ways. One is the use of new species with distinct physiological properties as a production host. Another is the transspecific transfer of such characteristics to the model systems. There is possibility of a large-scale interspecific exchange of specific physiological traits, ultimately leading to the creation of novel host organisms. The test target is the transfer of stress- tolerance characters known in some yeast species, especially osmo- and acid tolerance of several food associated yeasts in which genetic and molecular approaches are possible. Improvement of protein expression capacity will also be searched by random mutations introduced by heterospecific genome shuffling.
Ámbito científico
Tema(s)
Convocatoria de propuestas
Data not availableRégimen de financiación
CSC - Cost-sharing contractsCoordinador
75248 PARIS
Francia