The invention provides the LCB1 and LCB2 genes of the yeast Saccharomyces cerevisiae that encode subunits of the enzyme serine palmitoyltransferase (SPT), the first enzyme leading to synthesis of the long-base component of the sphingolipids. The present specification describes the isolation of the LCB1 and LCB2 genes. The invention further relates to methods of using these genes to either inhibit SPT activity or to inhibit synthesis of the enzyme. Furthermore, the invention relates to methods for constructing strains of S. cerevisiae or other organisms that can be used to select and to test for compounds that either inhibit SPT activity or to inhibit synthesis of the enzyme
