Identification of the minimal repression domain of SUPERMAN shows that the DLELRL hexapeptide is both necessary and sufficient for repression of transcription in Arabidopsis.
We reported previously that the carboxy-terminal 30 amino acids of SUPERMAN (SUPRD) function as a repression domain in Arabidopsis. In this study, we identified the peptide sequences in SUPRD that is both necessary and sufficient for repression of transcription. To our surprise, the hexapeptide DLELRL was sufficient, by itself, to confer the ability to repress transcription on a DNA-binding domain. A database search revealed that there are 32 TFIIIA-type zinc finger proteins in the Arabidopsis genome that contain a hexapeptide sequence similar or identical to that of DLELRL. These peptides acted as repression domains, suggesting that these zinc finger proteins might function as active repressors. Further mutational analysis within DLELRL revealed that an amphiphilic motif composed of six amino acids (XLxLXL) with preferences at the first and fifth positions is necessary and sufficient for strong repression. An assay of positional effects suggested that GAL4DB-DLELRL might function as a short-range repressor. A possible mechanism of the DLELRL-mediated repression is discussed.
Hiratsu
Keiichiro
K
Gene Function Research Center, National Institute of Advanced Industrial Technology and Science, Central 4, Tsukuba 305-8562, Japan.
Mitsuda
Nobutaka
N
Matsui
Kyoko
K
Ohme-Takagi
Masaru
M
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000378:metabolism*; D017930:Genes, Reporter; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry / Q000378:metabolism*; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism*; D030821:Plants, Genetically Modified; D012097:Repressor Proteins / Q000378:metabolism; D016385:TATA Box / Q000235:genetics; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*; D014158:Transcription, Genetic / Q000502:physiology*; D016335:Zinc Fingers
D029681:Arabidopsis Proteins; D009842:Oligopeptides; D010446:Peptide Fragments; D012097:Repressor Proteins; D014157:Transcription Factors; C096661:superman protein, Arabidopsis; D008156:Luciferases