TY - JOUR
T1 - Mapping and mutagenesis of the amino-terminal transcriptional repression domain of the Drosophila Kruppel protein
AU - Licht, J. D.
AU - Hanna-Rose, W.
AU - Reddy, J. C.
AU - English, M. A.
AU - Ro, M.
AU - Grossel, M.
AU - Shaknovich, R.
AU - Hansen, U.
PY - 1994
Y1 - 1994
N2 - We previously demonstrated that the Drosophila Kruppel protein is a transcriptional repressor with separable DNA-binding and transcriptional repression activities. In this study, the minimal amino (N)-terminal repression region of the Kruppel protein was defined by transferring regions of the Kruppel protein to a heterologous DNA-binding protein, the lacI protein. Fusion of a predicted α-helical region from amino acids 62 to 92 in the N terminus of the Kruppel protein was sufficient to transfer repression activity. This putative α-helix has several hydrophobic surfaces, as well as a glutamine-rich surface. Mutants containing multiple amino acid substitutions of the glutamine residues demonstrated that this putative α- helical region is essential for repression activity of a Kruppel protein containing the entire N-terminal and DNA-binding regions. Furthermore, one point mutant with only a single glutamine on this surface altered to lysine abolished the ability of the Kruppel protein to repress, indicating the importance of the amino acid at residue 86 for repression. The N terminus also contained an adjacent activation region localized between amino acids 86 and 117. Finally, in accordance with predictions from primary amino acid sequence similarity, a repression region from the Drosophila even-skipped protein, which was six times more potent than that of the Kruppel protein in the mammalian cells, was characterized. This segment included a hydrophobic stretch of 11 consecutive alanine residues and a proline-rich region.
AB - We previously demonstrated that the Drosophila Kruppel protein is a transcriptional repressor with separable DNA-binding and transcriptional repression activities. In this study, the minimal amino (N)-terminal repression region of the Kruppel protein was defined by transferring regions of the Kruppel protein to a heterologous DNA-binding protein, the lacI protein. Fusion of a predicted α-helical region from amino acids 62 to 92 in the N terminus of the Kruppel protein was sufficient to transfer repression activity. This putative α-helix has several hydrophobic surfaces, as well as a glutamine-rich surface. Mutants containing multiple amino acid substitutions of the glutamine residues demonstrated that this putative α- helical region is essential for repression activity of a Kruppel protein containing the entire N-terminal and DNA-binding regions. Furthermore, one point mutant with only a single glutamine on this surface altered to lysine abolished the ability of the Kruppel protein to repress, indicating the importance of the amino acid at residue 86 for repression. The N terminus also contained an adjacent activation region localized between amino acids 86 and 117. Finally, in accordance with predictions from primary amino acid sequence similarity, a repression region from the Drosophila even-skipped protein, which was six times more potent than that of the Kruppel protein in the mammalian cells, was characterized. This segment included a hydrophobic stretch of 11 consecutive alanine residues and a proline-rich region.
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U2 - 10.1128/mcb.14.6.4057
DO - 10.1128/mcb.14.6.4057
M3 - Article
C2 - 8196644
AN - SCOPUS:0028336737
VL - 14
SP - 4057
EP - 4066
JO - Molecular and Cellular Biology
JF - Molecular and Cellular Biology
SN - 0270-7306
IS - 6
ER -