Deletion of Autophagy gene ATG1 and F-box motif encoding gene YDR131C together leads to Synthetic Growth Defects and Flocculation behaviour in Saccharomyces cerevisiae

Abstract

F-box motif encoding YDR131C is functionally uncharacterized gene which forms the complex with the SCF-E3 ligase. The F-box motif containing proteins are involved in substrate recruitment for the ubiquitination and subsequent degradation through 26S proteasome. Autophagy gene, ATG1 (ULK1in human) is a well conserved serine-threonine kinase, required for vesicle formation and cytoplasm to vacuole targeting pathway. Atg1p forms the complex with Atg13p and Atg17p during autophagy. The understanding of crosstalk between ubiquitin and autophagy pathways is crucial for synthetic lethality screen and drug targeting. Here we have conducted the study for genetic interaction between uncharacterized YDR131C and ATG1 gene representing both specific and non-specific protein degradation pathways. The single and double gene knockout strains of YDR131Cand ATG1 genes were constructed in the BY4741 genetic background and analysed for growth fitness. The strains were also evaluated for cellular growth response in presence of hydroxyurea (HU), methyl methane sulfonate (MMS), and hydrogen peroxide (H2O2) stress causing agents by spot assay. The ydr131c{Delta}atg1{Delta} showed the synthetic growth defect phenotype with floc formation in rich medium which showed floc disruption in presence of EDTA. The ydr131c{Delta}atg1{Delta} cells showed the sensitivity to stress agents HU, MMS, and H2O2 when compared with ydr131c{Delta}, atg1{Delta}, and WT cells.. Based on the observations, we report that YDR131C and ATG1 functions in parallel pathways for growth fitness and cellular growth response to stress agents. Interestingly this study also revealed the crosstalk between ubiquitination and autophagy pathways. The defects in both the pathways could lead to synthetic growth defects which may have implication for the precision medicine initiatives.