Induction of 6-Aminolevulinic Acid Dehydratase in Mouse Friend Virus-Transformed Erythroleukemia Cells During Erythroid Differentiation

The activity of S-aminolevulinic acid (ALA) dehydratase. an enzyme involved in heme biosynthesis. has been shown to increase in Friend virus-transformed murine erythroleukemia (MEL) cells during erythroid differentiation. In this study. the nature of the increase in ALA dehydratase activity in MEL cells was examined using a monospecific antibody directed to the enzyme. A sevenfold increase in ALA dehydratase activity was observed after cells had been treated with 1 .5% Me2SO for 5 days. Ouchterlony double immunodiffusion analysis showed that lysates from untreated and Me2SO-treated MEL cells formed a single precipitin line with rabbit lgG directed to the normal mouse liver ALA dehydratase. A single arc of identity was also observed with the lysates from normal mouse erythrocytes, spleen. liver. and lysates from both uninduced and induced MEL cells. Rocket immunoelectrophoresis demonstrated that lysates from both uninduced and induced cells formed rockets with the lgG and that the peak height of the rocket was proportional to the ALA dehydratase activity