Abstract
The intracellular site of synthesis of mitochondrial ribosomal proteins (MRP) in Neurospora crassa has been investigated using three complementary approaches. (a) Mitochondrial protein synthesis in vitro: Tritium-labeled proteins made by isolated mitochondria were compared to 14C-labeled marker MRP by cofractionation in a two-step procedure involving isoelectric focusing and polyacrylamide gel electrophoresis. Examination of the electrophoretic profiles showed that essentially none of the peaks of in vitro product corresponded exactly to any of the MRP marker peaks. (b) Sensitivity of in vivo MRP synthesis to chloramphenicol: Cells were labeled with leucine-3H in the presence of chloramphenicol, mitochondrial ribosomal subunits were subsequently isolated, and their proteins fractionated by isoelectric focusing followed by gel electrophoresis. The labeling of every single MRP was found to be insensitive to chloramphenicol, a selective inhibitor of mitochondrial protein synthesis. (c) Sensitivity of in vivo MRP synthesis to anisomycin: We have found this antibiotic to be a good selective inhibitor of cytoplasmic protein synthesis in Neurospora. In the presence of anisomycin the labeling of virtually all MRP is inhibited to the same extent as the labeling of cytoplasmic ribosomal proteins. On the basis of these three types of studies we conclude that most if not all 53 structural proteins of mitochondrial ribosomal subunits in Neurospora are synthesized by cytoplasmic ribosomes.
Full Text
The Full Text of this article is available as a PDF (1.5 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Blobel G., Sabatini D. Dissociation of mammalian polyribosomes into subunits by puromycin. Proc Natl Acad Sci U S A. 1971 Feb;68(2):390–394. doi: 10.1073/pnas.68.2.390. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Davey P. J., Yu R., Linnane A. W. The intracellular site of formation of the mitochondrial protein synthetic system. Biochem Biophys Res Commun. 1969 Jul 7;36(1):30–34. doi: 10.1016/0006-291x(69)90644-5. [DOI] [PubMed] [Google Scholar]
- Grollman A. P. Inhibitors of protein biosynthesis. II. Mode of action of anisomycin. J Biol Chem. 1967 Jul 10;242(13):3226–3233. [PubMed] [Google Scholar]
- Hawley E. S., Greenawalt J. W. An assessment of in vivo mitochondrial protein synthesis in Neurospora crassa. J Biol Chem. 1970 Jul 25;245(14):3574–3583. [PubMed] [Google Scholar]
- Küntzel H., Noll H. Mitochondrial and cytoplasmic polysomes from Neurospora crassa. Nature. 1967 Sep 23;215(5108):1340–1345. doi: 10.1038/2151340a0. [DOI] [PubMed] [Google Scholar]
- LEBOY P. S., COX E. C., FLAKS J. G. THE CHROMOSOMAL SITE SPECIFYING A RIBOSOMAL PROTEIN IN ESCHERICHIA COLI. Proc Natl Acad Sci U S A. 1964 Dec;52:1367–1374. doi: 10.1073/pnas.52.6.1367. [DOI] [PMC free article] [PubMed] [Google Scholar]
- LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
- LUCK D. J., REICH E. DNA IN MITOCHONDRIA OF NEUROSPORA CRASSA. Proc Natl Acad Sci U S A. 1964 Oct;52:931–938. doi: 10.1073/pnas.52.4.931. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lai C. J., Weisblum B. Altered methylation of ribosomal RNA in an erythromycin-resistant strain of Staphylococcus aureus. Proc Natl Acad Sci U S A. 1971 Apr;68(4):856–860. doi: 10.1073/pnas.68.4.856. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Leon S. A., Mahler H. R. Isolation and properties of mitochondrial RNA from yeast. Arch Biochem Biophys. 1968 Jul;126(1):305–319. doi: 10.1016/0003-9861(68)90587-0. [DOI] [PubMed] [Google Scholar]
- Linnane A. W., Lamb A. J., Christodoulou C., Lukins H. B. The biogenesis of mitochondria, VI. Biochemical basis of the resistance of Saccharomyces cerevisiae toward antibiotics which specifically inhibit mitochondrial protein synthesis. Proc Natl Acad Sci U S A. 1968 Apr;59(4):1288–1293. doi: 10.1073/pnas.59.4.1288. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Linnane A. W., Saunders G. W., Gingold E. B., Lukins H. B. The biogenesis of mitochondria. V. Cytoplasmic inheritance of erythromycin resistance in Saccharomyces cerevisiae. Proc Natl Acad Sci U S A. 1968 Mar;59(3):903–910. doi: 10.1073/pnas.59.3.903. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lizardi P. M., Luck D. J. Absence of a 5S RNA complnent in the mitochondrial ribosomes of Neurospora crassa. Nat New Biol. 1971 Feb 3;229(5):140–142. doi: 10.1038/newbio229140a0. [DOI] [PubMed] [Google Scholar]
- Neth R., Monro R. E., Heller G., Battaner E., Vazquez D. Catalysis of peptidyl transfer by human tonsil ribosomes and effects of some antibiotics. FEBS Lett. 1970 Feb 16;6(3):198–202. doi: 10.1016/0014-5793(70)80056-4. [DOI] [PubMed] [Google Scholar]
- Neupert W., Sebald W., Schwab A. J., Massinger P., Bücher T. Incorporation in vivo of 14C-labelled amino acids into the proteins of mitochondrial ribosomes from Neurospora crassa sensitive to cycloheximide and insensitive to Chloramphenicol. Eur J Biochem. 1969 Oct;10(3):589–591. doi: 10.1111/j.1432-1033.1969.tb00730.x. [DOI] [PubMed] [Google Scholar]
- Neupert W., Sebald W., Schwab A. J., Pfaller A., Bücher T. Puromycin sensitivity of ribosomal label after incorporation of 14C-labelled amino acids into isolated mitochondria from Neurospora crassa. Eur J Biochem. 1969 Oct;10(3):585–588. doi: 10.1111/j.1432-1033.1969.tb00729.x. [DOI] [PubMed] [Google Scholar]
- Rifkin M. R., Luck D. J. Defective production of mitochondrial ribosomes in the poky mutant of Neurospora crassa. Proc Natl Acad Sci U S A. 1971 Feb;68(2):287–290. doi: 10.1073/pnas.68.2.287. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rifkin M. R., Wood D. D., Luck D. J. Ribosomal RNA and ribosomes from mitochondria of Neurospora crassa. Proc Natl Acad Sci U S A. 1967 Sep;58(3):1025–1032. doi: 10.1073/pnas.58.3.1025. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sebald W., Schwab A. J., Bücher T. Cycloheximide resistant amino acid incorporation into mitochondrial protein from Neurospora crassa in vivo. FEBS Lett. 1969 Aug;4(3):243–246. doi: 10.1016/0014-5793(69)80245-0. [DOI] [PubMed] [Google Scholar]
- Wood D. D., Luck D. J. Hybridization of mitochondrial ribosomal RNA. J Mol Biol. 1969 Apr;41(2):211–224. doi: 10.1016/0022-2836(69)90386-6. [DOI] [PubMed] [Google Scholar]