The role of predicted spermidine family transporters in stress response and cell cycle in Schizosaccharomyces pombe

Abstract

Fission yeast Schizosaccharomyces pombe has a variety of stress-signaling proteins that protect cells against environmental or intracellular stress. These proteins help the cells to respond to stress conditions and regulate intracellular functions such as cell division or gene expression. Polyamines (spermidine, spermine, and putrescine) are known to be important in the regulation of stress response and cell division. In this study, we tried to experimentally characterize novel S. pombe genes that are involved in the polyamine pathway and understand their potential roles. Sequence analysis revealed four genes that code for (predicted) spermidine family transporters in S. pombe. In an attempt to characterize these (predicted) spermidine family transmembrane transporters and their possible roles, deletion mutants of these candidate genes were created. These mutants were exposed to different stress conditions, such as DNA-damaging agents and osmotic stress, to understand their significance in the stress response. Next, the mutants were analyzed in terms of cell size, growth rate, and spore formation to understand their contribution to cell cycle control. The results revealed that individual deletion of two of these genes, SPBC36.01c and SPBC36.02c, resulted in sensitivity to DNA-damaging agents, indicating their role in DNA damage response.