Abstract
Expression of a 130 kDa protein from open reading frame 1 of the integrated form of the R2 mitochondrial plasmid in normal mitochondria of B37 and other inbred lines is described. The protein appears identical to that synthesized by the closely related S2 episome found in cytoplasmic male sterile maize of the S type. Protein was detected using antisera raised against a beta-galactosidase:ORF1 fusion product containing the most antigenic region of the ORF1 product. Detection of this protein is in contrast to previous reports that mitochondria of normal, male-fertile lines either do not contain this protein, or that there are 11 in-frame stop codons in the reading frame. The integrated R2 of B37N was cloned and this region sequenced, confirming that a continuous open reading frame existed. These results are discussed in relation to the possible role of the S-type episomes in causing cytoplasmic male sterility.
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- Braun C. J., Sisco P. H., Sederoff R. R., Levings C. S., 3rd Characterization of inverted repeats from plasmid-like DNAs and the maize mitochondrial genome. Curr Genet. 1986;10(8):625–630. doi: 10.1007/BF00418130. [DOI] [PubMed] [Google Scholar]
- Escote L. J., Gabay-Laughnan S. J., Laughnan J. R. Cytoplasmic reversion to fertility in cms-S maize need not involve loss of linear mitochondrial plasmids. Plasmid. 1985 Nov;14(3):264–267. doi: 10.1016/0147-619x(85)90011-3. [DOI] [PubMed] [Google Scholar]
- Hopp T. P., Woods K. R. Prediction of protein antigenic determinants from amino acid sequences. Proc Natl Acad Sci U S A. 1981 Jun;78(6):3824–3828. doi: 10.1073/pnas.78.6.3824. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kemble R. J., Gunn R. E., Flavell R. B. Classification of Normal and Male-Sterile Cytoplasms in Maize. II. Electrophoretic Analysis of DNA Species in Mitochondria. Genetics. 1980 Jun;95(2):451–458. doi: 10.1093/genetics/95.2.451. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kemble R. J., Mans R. J. Examination of the mitochondrial genome of revertant progeny from S cms maize with cloned S-1 and S-2 hybridization probes. J Mol Appl Genet. 1983;2(2):161–171. [PubMed] [Google Scholar]
- Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
- Laughnan J. R., Gabay-Laughnan S. Cytoplasmic male sterility in maize. Annu Rev Genet. 1983;17:27–48. doi: 10.1146/annurev.ge.17.120183.000331. [DOI] [PubMed] [Google Scholar]
- Leaver C. J., Hack E., Forde B. G. Protein synthesis by isolated plant mitochondria. Methods Enzymol. 1983;97:476–484. doi: 10.1016/0076-6879(83)97156-2. [DOI] [PubMed] [Google Scholar]
- Levings C. S., 3rd, Kim B. D., Pring D. R., Conde M. F., Mans R. J., Laughnan J. R., Gabay-Laughnan S. J. Cytoplasmic Reversion of cms-S in Maize: Association with a Transpositional Event. Science. 1980 Aug 29;209(4460):1021–1023. doi: 10.1126/science.209.4460.1021. [DOI] [PubMed] [Google Scholar]
- Levings C. S., Sederoff R. R. Nucleotide sequence of the S-2 mitochondrial DNA from the S cytoplasm of maize. Proc Natl Acad Sci U S A. 1983 Jul;80(13):4055–4059. doi: 10.1073/pnas.80.13.4055. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lonsdale D. M., Thompson R. D., Hodge T. P. The integrated forms of the S1 and S2 DNA elements of maize male sterile mitochondrial DNA are flanked by a large repeated sequence. Nucleic Acids Res. 1981 Aug 11;9(15):3657–3669. doi: 10.1093/nar/9.15.3657. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Manson J. C., Liddell A. D., Leaver C. J., Murray K. A protein specific to mitochondria from S-type male-sterile cytoplasm of maize is encoded by an episomal DNA. EMBO J. 1986 Nov;5(11):2775–2780. doi: 10.1002/j.1460-2075.1986.tb04567.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Peterson G. L. A simplification of the protein assay method of Lowry et al. which is more generally applicable. Anal Biochem. 1977 Dec;83(2):346–356. doi: 10.1016/0003-2697(77)90043-4. [DOI] [PubMed] [Google Scholar]
- Pring D. R., Levings C. S., Hu W. W., Timothy D. H. Unique DNA associated with mitochondria in the "S"-type cytoplasm of male-sterile maize. Proc Natl Acad Sci U S A. 1977 Jul;74(7):2904–2908. doi: 10.1073/pnas.74.7.2904. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rüther U., Müller-Hill B. Easy identification of cDNA clones. EMBO J. 1983;2(10):1791–1794. doi: 10.1002/j.1460-2075.1983.tb01659.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schardl C. L., Pring D. R., Lonsdale D. M. Mitochondrial DNA rearrangements associated with fertile revertants of S-type male-sterile maize. Cell. 1985 Nov;43(1):361–368. doi: 10.1016/0092-8674(85)90041-8. [DOI] [PubMed] [Google Scholar]
- Towbin H., Staehelin T., Gordon J. Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications. Proc Natl Acad Sci U S A. 1979 Sep;76(9):4350–4354. doi: 10.1073/pnas.76.9.4350. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ullmann A. One-step purification of hybrid proteins which have beta-galactosidase activity. Gene. 1984 Jul-Aug;29(1-2):27–31. doi: 10.1016/0378-1119(84)90162-8. [DOI] [PubMed] [Google Scholar]
- Zabala G., O'brien-Vedder C., Walbot V. S2 episome of maize mitochondria encodes a 130-kilodalton protein found in male sterile and fertile plants. Proc Natl Acad Sci U S A. 1987 Nov;84(22):7861–7865. doi: 10.1073/pnas.84.22.7861. [DOI] [PMC free article] [PubMed] [Google Scholar]




