A chemical compound for controlled expression of nmt1-driven gene in the fission yeast Schizosaccharomyces pombe

Abstract

The fission yeast Schizosaccharomyces pombe is a useful model organism for studying a variety of eukaryotic cellular events such as the cell cycle control mechanisms. For inducible expression of exogenous genes in S. pombe, vectors carrying the nmt1 ( no message in thiamine 1) promoter are most commonly used. Although nmt1 is a potent promoter, its transcription activity is drastically repressed in the presence of a low concentration of thiamine. Therefore, a combination of thiamine and nmt1 promoter is convenient for regulating gene expression in an all-or-none fashion. However, it has been difficult to adjust the nmt1 promoter activity in a controlled manner. Here we describe a chemical compound, designated as YAM2, whose repressive activity on the nmt1 promoter has a wider linear range than thiamine. Expression of exogenous proteins, such as human immunodeficiency virus type 1 Vpr and jellyfish green fluorescent protein, driven by the nmt1 promoter is gradually repressed by YAM2 in a dose-dependent manner. YAM2 does not exhibit a detectable level of cytotoxicity at a concentration required to fully repress the nmt1 promoter. The compound may serve as a useful tool for controlled expression of the nmt1-driven gene in S. pombe.