Isolation of a cDNA encoding an Arabidopsis galactokinase by functional expression in yeast
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A cDNA clone encoding Arabidopsis thaliana galactokinase was fortuitously isolated during the course of a screen for plant homologues of a Saccharomyces cerevisiae peroxisome assembly gene, PAS9. Clones were sought which restored the ability of pas9 cells to grow on oleate as a sole carbon source, as oleate metabolism requires peroxisomal β-oxidation and therefore functional peroxisomes. Subsequent experiments showed that high level expression of the galactokinase cDNA did not complement the peroxisomal assembly defect, but instead permitted the cells to grow on agar plates in the absence of an external carbon source. Agar plates were shown to contain a small amount of galactose released from the agar as a result of autoclaving. The galactokinase clone was shown to be functional, as it could complement a S. cerevisiae galactokinase mutant. Galactokinase is a single copy gene in Arabidopsis, which has been designated AGK1, and is expressed in all the major organs of the plant.
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- 3.Basehore SL, Hansen C, Braman J: Prime-It® RmT random primer labelling kit: stable at room temperature. Strat Mol Biol (Stratagene) 6: 13-14 (1993).Google Scholar
- 7.Cranshaw LA, Reid JSG: Changes in cell-wall polysaccharides in relation to seedling development and the mobilisation of reserves in the cotyledons of Lupinus angustifoliuscv Unicrop. Plant Physiol 160: 449-454 (1984).Google Scholar
- 12.Inouhe M, Yamamoto R, Masuda Y: Inhibition of IAA-induced cell elongation in Avenacoleoptile segments by galactose: its effect on UDP-glucose formation. Physiol Plant 66: 370-376 (1986).Google Scholar
- 15.Maretzki A, Thom M: Characteristics of a galactose adapted sugar cane cell line grown in suspension culture. Plant Physiol 61: 544-548 (1978).Google Scholar
- 18.Mori T: Seaweed polysaccharides. Adv. Carbohyd Chem 8: 317-328 (1953).Google Scholar
- 20.Ordin L, Bonner J: Effect of galactose on growth and metabolism of Avenacoleoptile sections. Plant Physiol 32: 212-215 (1957).Google Scholar
- 21.Roberts RM, Heishman A, Wicklin C: Growth inhibition and metabolite pool levels in plant tissues fed D-glucosamine and D-galactose. Plant Physiol 48: 36-42 (1971).Google Scholar
- 22.Sambrook J, Fritsch EF, Maniatis T: Molecular Cloning: A Laboratory Manual. Cold Spring Harbor Laboratory Press, Cold Spring Harbor (1989).Google Scholar