Dimerization of multiple maize ADHs studied in vivo and in vitro
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Anaerobically induced primary roots simultaneously express two alcohol dehydrogenase (Adh) genes which specify three types of electrophoretically separable dimers: Set I, II, and III ADH. The S inbred line yields a particular activity ratio among these three sets. By use of an Adh1 null mutant allele and in vitro chemical dissociation and reassociation of ADH dimers, these studies extrapolate from an ADH activity ratio to the actual ratio of ADH protein. Conclusions are that (1) ADH1 and ADH2 promoters dimerize randomly in vivo and in vitro, (2) the heterodimeric isozyme (Set II) is approximately the enzymological sum of its subunits under these assay conditions, and (3) ADH-2 subunits are from 10 to 20% as active as ADH1 subunits under these assay conditions. These conclusions imply that the unlinked Adh genes are coordinately regulated and reconfirm the two-gene-three-dimer model for the maize ADH isozymes.
Key wordsmaize alcohol dehydrogenase dissociation-reassociation dimerization gene regulation
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- Felder, M. R., Scandalios, J. G., and Liu, E. H. (1973). Purification and partial characterization of two genetically defined alcohol dehydrogenase isozymes in maize. Biochim. Biophys. Acta 318149.Google Scholar
- Fischer, M., and Schwartz, D. (1973). Dissociation and reassociation of maize alcohol dehydrogenase: Allelic differences in requirement of zinc. Mol. Gen. Genet. 12733.Google Scholar
- Freeling, M. (1973). Simultaneous induction by anaerobiosis or 2,4-D of multiple enzymes specified by two unlinked genes: Differential Adh 1 –Adh 2 expression in maize. Mol. Gen. Genet. 127215.Google Scholar
- Freeling, M., and Schwartz, D. (1973). Genetic relationships between the multiple alcohol dehydrogenases of maize. Biochem. Genet. 827.Google Scholar
- Hageman, R. H., and Flesher, D. (1960). The effect of an anaerobic environment on the activity of alcohol dehydrogenase and other enzymes of corn seedlings. Arch. Biochem. Biophys. 87203.Google Scholar
- Hart, G. E. (1971). Alcohol dehydrogenase isozymes in Triticum: Dissociation and recombination of subunits. Mol. Gen. Genet. 11161.Google Scholar
- Markert, C. L. (1963). Lactate dehydrogenase isozymes: Dissociation and recombination of subunits. Science 1401329.Google Scholar
- Scandalios, J. G. (1965). Subunit dissociation and recombination of catalase isozymes. Proc. Natl. Acad. Sci. 531035.Google Scholar
- Scandalios, J. G. (1969). Alcohol dehydrogenase in maize: Genetic basis for isozymes. Science 166623.Google Scholar
- Schwartz, D. (1966). The genetic control of alcohol dehydrogenase in maize: Gene duplication and repression. Proc. Natl. Acad. Sci. 561431.Google Scholar
- Schwartz, D. (1971). Dimerization mutants of alcohol dehydrogenase of maize. Proc. Natl. Acad. Sci. 68145.Google Scholar