title: TBP-like protein (TLP) interferes with Taspase1-mediated processing of TFIIA and represses TATA box gene expression.
abstract: TBP-TFIIA interaction is involved in the potentiation of TATA box-driven promoters. TFIIA activates transcription through stabilization of TATA box-bound TBP. The precursor of TFIIA is subjected to Taspase1-directed processing to generate α and β subunits. Although this processing has been assumed to be required for the promoter activation function of TFIIA, little is known about how the processing is regulated. In this study, we found that TBP-like protein (TLP), which has the highest affinity to TFIIA among known proteins, affects Taspase1-driven processing of TFIIA. TLP interfered with TFIIA processing in vivo and in vitro, and direct binding of TLP to TFIIA was essential for inhibition of the processing. We also showed that TATA box promoters are specifically potentiated by processed TFIIA. Processed TFIIA, but not unprocessed TFIIA, associated with the TATA box. In a TLP-knocked-down condition, not only the amounts of TATA box-bound TFIIA but also those of chromatin-bound TBP were significantly increased, resulting in the stimulation of TATA box-mediated gene expression. Consequently, we suggest that TLP works as a negative regulator of the TFIIA processing and represses TFIIA-governed and TATA-dependent gene expression through preventing TFIIA maturation.
authors.affiliation: Department of Biology, Graduate School of Science, Chiba University, 1-33 Yayoicho, Inage-ku, Chiba 263-8522, Japan h.suzuki-0204@chiba-u.jp.
authors.forename: Hidefumi
authors.initials: H
authors.lastname: Suzuki
authors.affiliation: Department of Biology, Graduate School of Science, Chiba University, 1-33 Yayoicho, Inage-ku, Chiba 263-8522, Japan.
authors.forename: Momoko
authors.initials: M
authors.lastname: Isogai
authors.affiliation: Department of Biology, Graduate School of Science, Chiba University, 1-33 Yayoicho, Inage-ku, Chiba 263-8522, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Maeda
authors.affiliation: Department of Biology, Graduate School of Science, Chiba University, 1-33 Yayoicho, Inage-ku, Chiba 263-8522, Japan.
authors.forename: Kiyoe
authors.initials: K
authors.lastname: Ura
authors.affiliation: Department of Biology, Graduate School of Science, Chiba University, 1-33 Yayoicho, Inage-ku, Chiba 263-8522, Japan.
authors.forename: Taka-Aki
authors.initials: TA
authors.lastname: Tamura
mesh_terms: D002460:Cell Line; D002843:Chromatin / Q000378:metabolism; D010450:Endopeptidases / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D012097:Repressor Proteins / Q000378:metabolism*; D016385:TATA Box; D035182:TATA Box Binding Protein-Like Proteins / Q000378:metabolism*; D035181:TATA-Box Binding Protein / Q000378:metabolism; D035561:Transcription Factor TFIIA / Q000378:metabolism*; D015533:Transcriptional Activation
chemical_list: D002843:Chromatin; D012097:Repressor Proteins; D035182:TATA Box Binding Protein-Like Proteins; D035181:TATA-Box Binding Protein; D035561:Transcription Factor TFIIA; D010450:Endopeptidases; C480823:taspase1, human