A new inducible protein expression system in fission yeast based on the glucose-repressed inv1 promoter

Studies of the fission yeast Schizosaccharomyces pombe have made major cont ributions towards understanding cell-cycle control and many other important aspects of cell biology. A series of pREP expression vectors that utilize the thiamine-repressible nmt1 promoter are used routinely to manipulate the expression of genes in fission yeast. A shortcoming of the nmt1 promoter i s that it is very slowly induced following removal of thiamine from the gro wth medium, requiring approx. 16 h for full induction. Invertase, an enzyme responsible for sucrose metabolism, is regulated transcriptionally by gluc ose derepression in S. pombe. Using the inv1 promoter, we have developed th e pINV1 set of inducible protein expression vectors. A shift from glucose t o sucrose-based culture medium leads to a very rapid induction of the inv1 promoter. Genes that are regulated by the inv1 promoter are fully induced w ithin Ih of the shift to sucrose-based medium. The pINV1 vectors utilize a simple induction protocol and enable studies in fission yeast requiring tig ht and rapid regulation of protein synthesis. (C) 1999 Elsevier Science B.V . All rights reserved.