The Biosynthesis of Mitochondrial Proteins

How mitochondria import proteins from the cytoplasm

“…Yeast F, consists of five non-identical subunits which are coded by nuclear genes. synthesized on extramitochondria1 60 S ribosomes and transported across both mitochondrial membranes to the matrix-side of the mitochondrial inner membrane [2,12]. Yeast F, has been studied in our laboratory for many years and monospecific antisera against the enzyme and its three largest subunits were already available [ 133.…”

“…these include three subunits of cytochrome c oxidase, the apoprotein of cytochrome h, at least two subunits of the oligomycin-sensitive ATPase complex and a polypeptlde (termed VII I) associated with the small Fubunit of mitochondrial ribosotnes [2,3].…”

Regulation of mitochondrial protein synthesis by cytoplasmic proteins.

“…In contrast, studies on the effect of cytoplasmic protein synthesis on mitochondrial protein synthesis have revealed that some cytoplasmically made proteins appear to exert a positive effect on the synthesis of mitochondrial translation products (1,2). As yet, the identity of these stimulatory proteins has not been established.…”

“…It is now clear that the biogenesis of a functional mitochondrion results from the collaborative effort of two physically separated and functionally distinct protein synthetic systems, mitochondrial and cytoplasmic (1,2). While the extramitochondrial, cytoplasmic protein synthetic system contributes the majority of both soluble and membrane-bound mitochondrial proteins, the role of the mitochondrial protein synthetic system appears to be limited to the production of [10][11][12][13][14][15] polypeptides that are hydrophobic and reside in the inner mitochondrial membrane (2)(3)(4).…”

Genetics of the mammalian oxidative phosphorylation system: characterization of a new oligomycin-resistant Chinese hamster ovary cell line.

“…Several components of the mitochondrial oxidative phosphorylation system (e.g., the ATPase, cytochrome c oxidase, and coenzyme QH2-cytochrome c reductase) require the synthesis and assembly of gene products coded by both the nuclear and the mitochondrial genomes (1,5,41,43,49). Mutations affecting various components of the oxidative phosphorylation system in lower eucaryotes and bacteria have contributed to our understanding of the synthesis and assembly of these gene products and have permitted mapping the genes for several of these products (for reviews, see references 5,15,41,49). These mutants have also been useful in studying the transmission, recombination, and segregation of genes coded by the mitochondrial DNA (for reviews, see references 3, 23).…”