Abstract:
RLM1 gene encodes for the MADS box transcription factor and involved in the cell wall integrity checkpoint in S. cerevisiae. RLM1p protein is phosphorylated and activated by the MAP-kinase Slt2p. RLM1 has been reported as activating transcription factor during stress. Nutrient limitation stress leads to situation where yeast cells enter into the quiescence state. During this stress the quiescence state promoting factor SAF1 gene product which constitutes the SCF E-3 ligase complex, recruits adenine deaminase factor Aah1p for ubquitination and subsequent degradation by 26S proteasome in S. cerevisiae. Here we investigated the association between RLM1 and SAF1 gene at transcriptional level for regulation during stress to understand the mechanism of cell cycle transition from active division to quiescence state in response to stress stimuli. For this we analyzed the expression profiling database (GEO) and yeast stress expression database ((http://www.ystrexdb.com) of S.cerevisiae cells for expression status of the RLM1, SAF1 genes in stress conditions. We observed that in variety of stress conditions (drug, pH, temperature, microbial toxin, inorganic compound) the RLM1 and SAF1 was constitutively over expressed at log2FC>1 and adjusted p-value < 0.05 setting in comparison to control cells. Further we analysed the association matrix between SAF1 gene and RLM1 using yeastextract (http://www.yeastract.com/) web tool for the association between genes and transcription factors. The analysis predicted the regulation of SAF1 gene by RLM1 transcription factor during stress conditions. Based on analysis we hypothesized that double knockout of saf1 and rlm1 genes cells may be resistant to stress condition which need to be tested experimentally.
(Acknowledgement: The authors acknowledge the support of Department of Biotechnology, GOI).