A novel HSP70 gene of Schizosaccharomyces pombe that confers K-252a resistance.

Abstract A new gene encoding a heat shock protein 70 family protein of Schizosaccharomyces pombe ( Sp ), named sks2 + , was cloned as a weak suppressor for the K-252a-sensitive mutation, ucm1 . The nucleotide sequence of sks2 + revealed an open reading frame of a 613-amino-acid (aa) protein. The deduced aa sequence of sks2 + showed significant homology with Saccharomyces cerevisiae ( Sc ) Ssb1p and Ssb2p responsible for protein synthesis by non-organelle-localized ribosomes, as well as with other proteins of the HSP70 family. The cells lacking the functional sks2 + gene were viable and showed no increased sensitivity to K-252a but grew slowly with an elongated morphology. These results suggest that the sks2 + gene product plays a role in the cell cycle progression and is able to confer drug resistance in a multicopy state.