Two cytoplasmically inherited oligomycin-resistant Chinese hamster cell lines exhibit an altered mitochondrial translation product

Abstract

Mitochondria from two different cytoplasmically inherited oligomycin-resistant Chinese hamster ovary cell lines synthesize an altered polypeptide compared to mitochondria from wild-type cells. For example, mitochondria from both oligomycin-resistant cell lines synthesize a polypeptide with a molecular weight of approximately 20,500, which is present in very low amounts in wild-type cells. In contrast, mitochondria from wild-type cells synthesize a polypeptide with a molecular weight of approximately 19,500, which is present in very low amounts in one of the oligomycin-resistant mutants and in reduced amounts in the other mutant. The gene which encodes this altered polypeptide is cytoplasmically transferred together with the oligomycin-resistant phenotype. This is the first example in mammalian cells where an altered mitochondrial gene product is shown to be associated with the cytoplasmic transfer of oligomycin resistance.

Coordinate reciprocal trends in glycolytic and mitochondrial transcript accumulations during the in vitro differentiation of human myoblasts

“…In patients with a maternally inherited neuromuscular disease, the ratio of the ATPase6 and COIII polypeptides changes reciprocally relative to controls . The same phenomenon was observed in a Chinese hamster cell line with a n ATPase6 mutation resulting in oligomycin resistance (Shew and Breen, 1985). Since ATPase6 and COIII are key functional components of the ATP synthase, which synthesizes ATP, and cytochrome c oxidase, which is the terminal electron carrier, it is possible that differential processing of the ATPase8 + 6 COIII transcript might permit coordination between electron transport and ATP synthesis.…”