The Silencing of Septin 1 via Synthetic siRNAs in Schizosaccharomyces pombe

Septins are evolutionary conserved GTP-binding proteins and form heterooligomers in cells to interact with cytoskeleton. The main roles of septins in cell are cytokines, membrane interactions, vesicle trafficking and microtubule and actin organization. Non-coding RNAs are key players of gene expression regulation. Small-interfering RNAs (siRNAs) belong to non-coding RNAs, are characterized by sequence complementarity to their target mRNAs. siRNAs silence their targets via mRNA degradation or inhibition of translation. In S. pombe siRNAs can also propagate heterochromatin to silence genes located in centromeric regions. In this study, the aim was understanding the results of extrinsically induced siRNA silencing in S. pombe by using synthetic siRNAs specific to Septin 1 gene. siRNAs were introduced to cells by lipid-based vesicles and the alterations in Septin 1 expressions were monitored with qPCR. Septin 1 expression was reduced dramatically via direct siRNA introduction to cells. The interactions between cell morphology and the reduced level of Septin 1 were observed after accomplishing the silencing of Septin 1 gene. In this study, it is shown that the morphology of the cells is affected by the reduced levels of Septin 1 expression and the cells form long and chain-like structures. This study constitutes an important example in understanding the results of inducing siRNA silencing extrinsically in S. pombe.