PROTEIN PRENYLATION IN TETRAHYMENA

Tetrahymena vorax V2S and Tetrahymena pyriformis GL were examined for the presence of proteins covalently modified with mevalonate-derived l ipids. Radiolabeling of cells using [H-3]mevalonolactone, [H-3]mevalon ate, [H-3]farnesyl pyrophosphate or [H-3]geranylgeranyl pyrophosphate resulted in the appearance of protein-associated radioactivity followi ng protein delipidation in acetone. Sodium dodecyl sulfate-polyacrylam ide gel electrophoresis of labeled protein revealed radioactive polype ptides ranging in molecular mass from 123 to 14 kDa following scintill ation counting of gel slices or fluorography. Methyl iodide cleavage o f total labeled protein followed by HPLC analysis and scintillation co unting of the released prenyl alcohols showed radioactive peaks that c o-chromatographed with commercially obtained farnesol (C-15) and geran ylgeraniol (C-20).