Identification of Gene Products Involved in Glycerophosphoinositol Metabolism in Saccharomyces cerevisiae

Phosphatidylinositol deacylation by gene products encoded by PLB1,2,3 results in the formation of glycerophosphoinositol (GroPIns) in Saccharomyces cerevisiae. Both internal and external GroPIns are formed as a result of phospholipids turnover in S. cerevisiae. Under conditions of phosphate starvation, GroPIns is transported into the cell via the Git1p transporter, coded by the GIT1 gene. Once inside the cell, GroPIns undergo hydrolysis to provide the cell with crucial nutrients such as inositol and phosphate. Here, I report the identification of some gene products that might be involved in GroPIns metabolism. Viable yeast knock-out (YKO) set was screened for mutants defective in their utilization of GroPIns as a sole phosphate source. Next, studies were performed on the expression of GIT1, and Git1p activity via chloroamphenicol acetyl transferase (CAT) assay and GroPIns transport assay, respectively. This study led to the identification of some gene products whose deletion led to alterations in GIT1 promoter-driven CAT activity and GroPIns transport in the mutants