A human promyelocyte mRNA transiently induced by TPA is homologous to yeast IPP isomerase.

A cDNA clone was isolated from HL60 human promyelocyte cells on the basis of the induction of its cognate mRNA by the phorbol ester TPA (12-O-tetradecanoyl phorbol-13-acetate) in the presence of cycloheximide. Northern analysis showed a peak of induction of a 1.9-kb mRNA at 3-6 h after TPA addition. Sequence analysis revealed that this cDNA was likely a human homolog of yeast isopentenyl diphosphate:dimethylallyl diphosphate isomerase, an enzyme important for isoprenoid synthesis and the prenylation of proteins such as ras p21.