Biosynthesis of adrenodoxin in mouse adrenal tumor cells

ACTH and cAMP stimulate steroidogenesis and the mitochondrial electron transport system for steroid hydroxylation in cultured mouse adrenal cortex tumor cells. During this stimulation, the biosynthesis of adrenodoxin, a non-heme iron protein which is one of the electron transport enzymes, was examined. 14C-labeled adrenodoxin was isolated by employing a purified rabbit antibody to bovine adrenodoxin. The antibody-adrenodoxin precipitates were further purified by acrylamide gel electrophoresis. It was observed that the biosynthesis of adrenodoxin was stimulated in response to ACTH induction and that this stimulation was completely inhibited with cycloheximide and partially inhibited with chloramphenicol. As a result, it was concluded that adrenodoxin requires both mitochondrial and cytosol ribosomal activities for its synthesis and integration into adrenal mitochondria.