Interaction of a GATA factor with cis-acting elements involved in light regulation of nuclear genes encoding chloroplast glyceraldehyde-3-phosphate dehydrogenase in Arabidopsis.
We have previously identified a cis-acting element, named the XXIII box, that is essential for light-regulated expression of the nuclear gene GAPB, which encodes the B subunit of chloroplast glyceraldehyde-3-phosphate dehydrogenase from Arabidopsis thaliana. Examination of the sequences indicated that there are two GATA motifs within the XXIII box. Based on the degree of the amino-acid sequence identity in the DNA binding domains, we divided the 25 GATA factors encoded in the Arabidopsis genome into three classes. We chose GATA-1 and GATA-20 from Class I and Class II, which include the majority of GATA factors, for overexpression in an Escherichia coli expression system. Gel mobility shift assays showed that GATA-1, but not GATA-20, binds specifically to the two GATA motifs within the XXIII fragment. In addition, we showed that GATA-1 could also bind specifically to a cis-acting element in the promoter of the GAPA gene, which is coordinately regulated by light with the GAPB gene. Based on these results, we propose that light controls the expression of GAPA and GAPB genes in part by regulating the binding of the same transcription factor at their GATA motifs.
Jeong
Mi-Jeong
MJ
Department of Biological Sciences, 204 Chemistry Building, University of Iowa, Iowa City, IA 52242, USA.
Jeong
Me-Jeong
MJ
Shih
Ming-Che
MC
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D001483:Base Sequence; D002467:Cell Nucleus / Q000235:genetics; D002736:Chloroplasts / Q000201:enzymology; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D004790:Enzyme Induction; D050981:Erythroid-Specific DNA-Binding Factors; D004926:Escherichia coli / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics*; D008027:Light; D020218:Response Elements; D016415:Sequence Alignment; D014157:Transcription Factors / Q000737:chemistry / Q000145:classification / Q000378:metabolism*; D015533:Transcriptional Activation
D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D014157:Transcription Factors; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases