Identification of functional domains in the maize transcriptional activator C1: comparison of wild-type and dominant inhibitor proteins

S A Goff, K C Cone, M E Fromm
1991 Genes & Development  
Genes encoding fusions between the maize regulatory protein CI and the yeast transcriptional activator GAL4 and mutant CI proteins were assayed for their ability to trans-activate anthocyanin biosynthetic genes in intact maize tissues. The putative DNA-binding region of CI fused to the transcriptional activation domain of GAL4 activated transcription of anthocyanin structural gene promoters in cl aleurones, cl Rscm2 embryos, and cl r embryogenic callus. Cells receiving these constructs
more » ... ed purple anthocyanin pigments. The Cl acidic region fused to the GAL4 DNA-binding domain activated transcription of a GAL4-regulated promoter. An internal deletion of Cl also induced pigmentation; however, frameshifts in either the amino-terminal basic or carboxy-terminal acidic region blocked tra/is-activation, and the latter generated a dominant inhibitory protein. Fusion constructs between the wild-type Cl cDNA and the dominant inhibitor allele Cl-I cDNA were used to identify the amino acid changes in Cl responsible for the Cl-I inhibitory phenotype. Results from these studies establish that amino acids within the myb-homologous domain are critical for transcriptional activation.
doi:10.1101/gad.5.2.298 pmid:1995419 fatcat:qcwl5a3tszgz5lljwp3hz45ypi