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Identification of the polypeptides encoded in the unassigned reading frames 2, 4, 4L, and 5 of human mitochondrial DNA

Mariottini, Paolo and Chomyn, Anne and Riley, Marcia and Cottrell, Barbara and Doolittle, Russell F. and Attardi, Giuseppe (1986) Identification of the polypeptides encoded in the unassigned reading frames 2, 4, 4L, and 5 of human mitochondrial DNA. Proceedings of the National Academy of Sciences of the United States of America, 83 (6). pp. 1563-1567. ISSN 0027-8424. PMCID PMC323123. doi:10.1073/pnas.83.6.1563.

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In previous work, antibodies prepared against chemically synthesized peptides predicted from the DNA sequence were used to identify the polypeptides encoded in three of the eight unassigned reading frames (URFs) of human mitochondrial DNA (mtDNA). In the present study, this approach has been extended to other human mtDNA URFs. In particular, antibodies directed against the NH2-terminal octapeptide of the putative URF2 product specifically precipitated component 11 of the HeLa cell mitochondrial translation products, the reaction being inhibited by the specific peptide. Similarly, antibodies directed against the COOH-terminal nonapeptide of the putative URF4 product reacted specifically with components 4 and 5, and antibodies against a COOH-terminal heptapeptide of the presumptive URF4L product reacted specifically with component 26. Antibodies against the NH2-terminal heptapeptide of the putative product of URF5 reacted with component 1, but only to a marginal extent; however, the results of a trypsin fingerprinting analysis of component 1 point strongly to this component as being the authentic product of URF5. The polypeptide assignments to the mtDNA URFs analyzed here are supported by the relative electrophoretic mobilities of proteins 11, 4-5, 26, and 1, which are those expected for the molecular weights predicted from the DNA sequence for the products of URF2, URF4, URF4L, and URF5, respectively. With the present assignment, seven of the eight human mtDNA URFs have been shown to be expressed in HeLa cells.

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Additional Information:© 1986 by the National Academy of Sciences. Contributed by Giuseppe Attardi, October 21, 1985. The technical assistance of Ms. Doris Finch and Ms. Arger Drew is gratefully acknowledged. These investigations were supported by National Institutes of Health Grants GM-11726 (to G.A.) and National Science Foundation grant PCM-8118172 to R.F.D. The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.
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Subject Keywords:HeLa cells, synthetic peptides, antibodies, mitochondrial translation products
Issue or Number:6
PubMed Central ID:PMC323123
Record Number:CaltechAUTHORS:MARpnas86b
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:1137
Deposited By: Tony Diaz
Deposited On:22 Dec 2005
Last Modified:08 Nov 2021 19:07

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