Identification and characterization of four novel peptide motifs that recognize distinct regions of the transcription factor CP2.
Although ubiquitously expressed, the transcriptional factor CP2 also exhibits some tissue- or stage-specific activation toward certain genes such as globin in red blood cells and interleukin-4 in T helper cells. Because this specificity may be achieved by interaction with other proteins, we screened a peptide display library and identified four consensus motifs in numerous CP2-binding peptides: HXPR, PHL, ASR and PXHXH. Protein-database searching revealed that RE-1 silencing factor (REST), Yin-Yang1 (YY1) and five other proteins have one or two of these CP2-binding motifs. Glutathione S-transferase pull-down and coimmunoprecipitation assays showed that two HXPR motif-containing proteins REST and YY1 indeed were able to bind CP2. Importantly, this binding to CP2 was almost abolished when a double amino acid substitution was made on the HXPR sequence of REST and YY1 proteins. The suppressing effect of YY1 on CP2's transcriptional activity was lost by this point mutation on the HXPR sequence of YY1 and reduced by an HXPR-containing peptide, further supporting the interaction between CP2 and YY1 via the HXPR sequence. Mapping the sites on CP2 for interaction with the four distinct CP2-binding motifs revealed at least three different regions on CP2. This suggests that CP2 recognizes several distinct binding motifs by virtue of employing different regions, thus being able to interact with and regulate many cellular partners.
Kang
Ho Chul
HC
Department of Life Science, Hanyang University, Korea.
Chung
Bo Mee
BM
Chae
Ji Hyung
JH
Yang
Sung-Il
SI
Kim
Chan Gil
CG
Kim
Chul Geun
CG
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D002478:Cells, Cultured; D004247:DNA / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D050981:Erythroid-Specific DNA-Binding Factors; D005786:Gene Expression Regulation; D006801:Humans; D047468:Immunoprecipitation; D008156:Luciferases; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019151:Peptide Library; D017354:Point Mutation; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D050986:YY1 Transcription Factor; D016335:Zinc Fingers; D000099229:RE1-Silencing Transcription Factor
D004247:DNA; D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D008156:Luciferases; D010446:Peptide Fragments; D019151:Peptide Library; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; D050986:YY1 Transcription Factor; D000099229:RE1-Silencing Transcription Factor; C501906:TFCP2 protein, human; C494698:YY1 protein, human