FIG. 2.

Interactions between the Pdr pathway and sphingolipid biosynthesis. An outline of the biosynthetic pathway producing sphingolipids is depicted. Arrows indicate enzymatic reactions. Genes encoding proteins involved in selected pathway reactions are shown. The black boxes denote genes that are believed to be regulated by Pdr1p and/or Pdr3p. Rsb1p can transport both DHS and PHS (56). M(IP)₂C is mannosyl diinositolphospho-ceramide (31), the final product of the sphingolipid pathway in S. cerevisiae.