Molt4–1D10 and CHOPA10.14 cells are defective in PIG-W. (A) Rat PIG-W cDNA restored the surface expression of CD59 on Molt4–1D10 and CHOPA10.14 cells. 1D10 mutant transfected with an empty vector (a) or PIG-W (b) and CHOPA10.14 mutant transfected with an empty vector (c) or PIG-W (d) were stained 2 d after transfection. Solid lines, transfectants; dotted lines, wild-type cells. (B) Normalized GPI biosynthesis in 1D10 cells transfected with PIG-W cDNA. Wild-type Molt4 (lane 1), 1D10 mutant (lane 2), 1D10 transfected with rat PIG-W cDNA (lane 3), and 1D10 mutant transfected with an empty vector (lane 4) were labeled with [3H]mannose and lipids analyzed by TLC.