Rat liver L-glutamate dehydrogenase, malate dehydrogenase, D-beta-hydroxybutyrate dehydrogenase, and sulfite oxidase are each synthesized as larger precursors by cytoplasmic free polysomes.

Published

Journal Article

Four cytoplasmically synthesized rat liver mitochondrial enzymes, located either as soluble enzymes in the mitochondrial matrix (L-glutamate dehydrogenase and malate dehydrogenase or in the intermembrane space (sulfite oxidase) or as an integral membrane protein located on the matrix face of the inner mitochondrial membrane (D-beta-hydroxybutyrate dehydrogenase), were all shown to be synthesized as precursors larger than their mature counterparts by 1000-6000 daltons. These larger forms were detected in vitro, in a cell-free protein synthesizing system programmed with either total rat liver RNA or with RNA isolated from free polysomes or with free polysomes, and in vivo, in the two cases that were investigated (L-glutamate dehydrogenase and D-beta-hydroxybutyrate dehydrogenase), by pulse labeling of Buffalo rat liver cells in culture. The intracellular site of synthesis of all four mitochondrial enzymes was shown to be primarily on free polysomes and not on membrane-bound polysomes.

Full Text

Duke Authors

Cited Authors

  • Mihara, K; Omura, T; Harano, T; Brenner, S; Fleischer, S; Rajagopalan, KV; Blobel, G

Published Date

  • April 1982

Published In

Volume / Issue

  • 257 / 7

Start / End Page

  • 3355 - 3358

PubMed ID

  • 7061482

Pubmed Central ID

  • 7061482

Electronic International Standard Serial Number (EISSN)

  • 1083-351X

International Standard Serial Number (ISSN)

  • 0021-9258

Language

  • eng