Abstract
The role of heme in regulation of the synthesis of cytochrome oxidase, a mitochondrial hemoprotein, was studied in fetal rat liver. A functional association between heme levels and the synthesis of cytochrome oxidase in vivo is suggested by the rapid decline in the rate of incorporation of [3H]δ-aminolevulinic acid and, subsequently, [14C]leucine into cytochrome oxidase following selective inhibition of heme biosynthesis with CoCl2. Both the functional activity and the rate of [14C]leucine incorporation into fetal cytochrome oxidase are stimulated when heme is administered 30 min after CoCl2 is given. In contrast, heme does not stimulate [14C]leucine incorporation or enhance the functional activity of cytochrome oxidase following selective inhibition of cytoribosomal protein synthesis with cycloheximide. Thus it is suggested that heme stimulates the synthesis of apocytochrome oxidase de novo and mediates the formation of the functional cytochrome in fetal rat liver.
ACKNOWLEDGMENTS The author acknowledges the excellent technical assistance of Mrs. Geraldine Carver in the performance of these studies.
- Copyright © 1977 by Academic Press, Inc.
MolPharm articles become freely available 12 months after publication, and remain freely available for 5 years.Non-open access articles that fall outside this five year window are available only to institutional subscribers and current ASPET members, or through the article purchase feature at the bottom of the page.
|