Pit-1β reduces transcription and CREB-binding protein recruitment in a DNA context-dependent manner
| Autor: | K Brodsky, J C Bailey, C J Hoon, M D Jonsen, A L Ferry, A Gutierrez-Hartmann, D M Locasto, Scott E. Diamond, L B Meszaros |
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| Rok vydání: | 2005 |
| Předmět: |
Transcription
Genetic Endocrinology Diabetes and Metabolism Blotting Western Response element CREB Histones Transactivation Endocrinology Sp3 transcription factor Pituitary Gland Anterior Cell Line Tumor Animals Immunoprecipitation Protein Isoforms Pituitary Neoplasms CREB-binding protein Promoter Regions Genetic Transcription factor biology Nuclear Proteins Acetylation Promoter CREB-Binding Protein Molecular biology Chromatin Prolactin Rats DNA-Binding Proteins Electroporation Gene Expression Regulation Growth Hormone Trans-Activators biology.protein Transcription Factor Pit-1 CREB1 Transcription Factors |
| Zdroj: | Journal of Endocrinology. 185:173-185 |
| ISSN: | 1479-6805 0022-0795 |
| Popis: | Many transcription factors are expressed as multiple isoforms with distinct effects on the regulation of gene expression, and the functional consequences of structural differences between transcription factor isoforms may allow for precise control of gene expression. The pituitary transcription factor isoforms Pit-1 and Pit-1beta differentially regulate anterior pituitary hormone gene expression. Pit-1 is required for the development of and appropriate hormone expression by anterior pituitary somatotrophs and lactotrophs. Pit-1beta differs structurally from Pit-1 by the splice-insertion of the 26-residue beta-domain in the trans-activation domain, and it differs functionally from Pit-1 in that it represses expression of the prolactin promoter in a cell-type specific manner. In order to identify signal and promoter context requirements for repression by Pit-1beta, we examined its function in the presence of physiological regulatory signals as well as wild-type and mutant Pit-1-dependent target promoters. Here, we demonstrate that Pit-1beta impairs recruitment of cAMP response element-binding protein (CREB)-binding protein to the promoters that it represses. In addition, we show that repression of target promoter activity, reduction in promoter histone acetylation, and decrease of CREB-binding protein recruitment all depend on promoter context. These findings provide a mechanism for promoter-specific repression by Pit-1beta. |
| Databáze: | OpenAIRE |
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