title: MIDA1, an Id-associating protein, has two distinct DNA binding activities that are converted by the association with Id1: a novel function of Id protein.
abstract: Id proteins not only regulate cell differentiation negatively, but they also promote growth, immortalization, and apoptosis. To know the mechanism of how Id regulates cell fate, we previously isolated an Id-associating protein, MIDA1, which positively regulates cell growth (1). Its predicted amino acid sequence consists of a Zuotin (a Z-DNA binding protein in yeast) homology region and tryptophan-mediated repeats (Tryp-med repeats). MIDA1 exhibits a sequence-specific DNA binding activity through the Tryp-med repeats (manuscript in preparation). In this study, we revealed that, like Zuotin, MIDA1 can specifically bind to Z-DNA. This suggested that MIDA is a novel DNA binding protein that has two different DNA binding activities. Furthermore, association of Id1 with MIDA1 stimulated the sequence-specific DNA binding activity, while it inhibited the Z-DNA binding activity. Therefore, we concluded that MIDA1 may act as a mediator of the growth-promoting function of Id, by switching the two DNA binding activities of MIDA1.
authors.affiliation: Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryomachi, Aoba-ku, Sendai, 980-8575, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Inoue
authors.forename: W
authors.initials: W
authors.lastname: Shoji
authors.forename: M
authors.initials: M
authors.lastname: Obinata
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D016384:Consensus Sequence / Q000235:genetics; D004247:DNA / Q000235:genetics / Q000378:metabolism*; D015342:DNA Probes / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism; D051798:Inhibitor of Differentiation Protein 1; D051379:Mice; D018832:Molecular Chaperones; D011993:Recombinant Fusion Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020449:Repetitive Sequences, Amino Acid / Q000235:genetics; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D017384:Sequence Deletion / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014364:Tryptophan / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D015342:DNA Probes; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C497455:Idb1 protein, mouse; D051798:Inhibitor of Differentiation Protein 1; D018832:Molecular Chaperones; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C077019:ZUO1 protein, S cerevisiae; C096145:Zrf2 protein, mouse; D014364:Tryptophan; D004247:DNA