Brachyury-related transcription factor Tbx2 and repression of the melanocyte-specific TRP-1 promoter

dc.citation.epage5108en_US
dc.citation.issueNumber9en_US
dc.citation.spage5099en_US
dc.citation.volumeNumber18en_US
dc.contributor.authorCarreira, S.en_US
dc.contributor.authorDexter, T. J.en_US
dc.contributor.authorYavuzer, U.en_US
dc.contributor.authorEasty, D. J.en_US
dc.contributor.authorGoding, C. R.en_US
dc.date.accessioned2016-02-08T10:44:26Z
dc.date.available2016-02-08T10:44:26Z
dc.date.issued1998en_US
dc.departmentDepartment of Molecular Biology and Geneticsen_US
dc.description.abstractPrevious work has demonstrated that two key melanocyte-specific elements termed the MSEu and MSEi play critical roles in the expression of the melanocyte-specific tyrosinase-related protein 1 (TRP-1) promoter. Both the MSEu and MSEi, located at position -237 and at the initiator, respectively, bind a melanocyte-specific factor termed MSF but are also recognized by a previously uncharacterized repressor, since mutations affecting either of these elements result in strong up-regulation of TRP-1 promoter activity in melanoma cells. Here we demonstrate that repression mediated by the MSEu and MSEi also operates in melanocytes. We also report that both the MSEu and MSEi are recognized by the brachyury-related transcription factor Tbx2, a member of the recently described T-box family, and that Tbx2 is expressed in melanocyte and melanoblast cell lines but not in melanoblast precursor cells. Although Tbx2 and MSF each recognize the TRP-1 MSEu and MSEi motifs, it is binding by Tbx-2, not binding by MSF, that correlates with repression. Several lines of evidence tend to point to the brachyury-related transcription factor Tbx2 as being the repressor of TRP-1 expression: both the MSEu and MSEi bind Tbx2, and mutations in either element that result in derepression of the TRP-1 promoter diminish binding by Tbx2; the TRP-1 promoter, but not the tyrosinase, microphthalmia, or glyceraldehyde-3- phosphate dehydrogenase (G3PDH) promoter, is repressed by Tbx2 in cotransfection assays; a high-affinity consensus brachyury/Tbx2-binding site is able to constitutively repress expression of the heterologous IE110 promoter; and a low-affinity brachyury/Tbx2 binding site is able to mediate Tbx2-dependent repression of the G3PDH promoter. Although we cannot rule out the presence of an additional, as yet unidentified factor playing a role in the negative regulation of TRP-1 in vivo, the evidence presented here suggests that Tbx2 most likely is the previously unidentified repressor of TRP-1 expression and as such is likely to represent the first example of transcriptional repression by a T-box family member.en_US
dc.description.provenanceMade available in DSpace on 2016-02-08T10:44:26Z (GMT). No. of bitstreams: 1 bilkent-research-paper.pdf: 70227 bytes, checksum: 26e812c6f5156f83f0e77b261a471b5a (MD5) Previous issue date: 1998en
dc.identifier.issn0270-7306
dc.identifier.urihttp://hdl.handle.net/11693/25421
dc.language.isoEnglishen_US
dc.source.titleMolecular and Cellular Biologyen_US
dc.subjectTranscription factoren_US
dc.subjectAnimal cellen_US
dc.subjectGene expression regulationen_US
dc.subjectGene repressionen_US
dc.subjectGene structureen_US
dc.subjectMelanocyteen_US
dc.titleBrachyury-related transcription factor Tbx2 and repression of the melanocyte-specific TRP-1 promoteren_US
dc.typeArticleen_US

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