Open AccessRegulation of mitochondrial protein synthesis by cytoplasmic proteins.
Author(s) -
Robert O. Poyton,
Jeanne Kavanagh
Publication year - 1976
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.73.11.3947
Subject(s) - cytoplasm , mitochondrion , protein biosynthesis , cytochrome c oxidase , biochemistry , biology , microbiology and biotechnology
Isolated yeast mitochondria, which synthesize identifiable polypeptides identical to those made in vivo, have been used in an invitro system to study cytoplasmic control of mitochondrial protein synthesis. It has been found that protein synthesis in isolated mitochondria is dependent on an endogenous pool of cytoplasmically synthesized proteins present within mitochondria at the time of isolation, that protein synthesis ceases apparently when this pool of proteins is depleted, and that a cytoplasmic extract can restore protein synthesis in depleted mitochondria. By use of depleted mitochondria to assay for stimulatory factors it has been found that the bulk of the stimulatory activity in the cytoplasm is of a protein nature and resides predominantly in the postpolysomal supernatant. At least one cytoplasmic stimulatory protein appears to exert a specific effect on the synthesis of subunits I-III of cytochrome c oxidase (ferrocytochrome c:oxygen oxidoreductase; EC 1.9.3.1).