Project description:Transcriptional regulators are crucial in adipocyte differentiation. We now show that the homeodomain-containing transcription factor Prep1 is a repressor of adipogenic differentiation since its down-regulation (DR) in both ex vivo bone marrow-derived mesenchymal stromal cells (MSC) and in vitro 3T3-L1 pre-adipocytes significantly increases their adipogenic differentiation ability. Prep1 acts at a stage preceding the activation of the differentiation machinery because its DR makes cells more prone to adipogenic differentiation even in the absence of the adipogenic inducers. Prep1 DR expands the DNA binding landscape of C/EBPß(CAAT enhancer binding protein ß) without affecting its expression or activation. The data indicate that Prep1 normally acts by restricting DNA binding of transcription factors to adipogenic enhancers, in particular C/EBPß.
Project description:Transcriptional regulators are crucial in adipocyte differentiation. We now show that the homeodomain-containing transcription factor Prep1 is a repressor of adipogenic differentiation since its down-regulation (DR) in both ex vivo bone marrow-derived mesenchymal stromal cells (MSC) and in vitro 3T3-L1 pre-adipocytes significantly increases their adipogenic differentiation ability. Prep1 acts at a stage preceding the activation of the differentiation machinery because its DR makes cells more prone to adipogenic differentiation even in the absence of the adipogenic inducers. Prep1 DR expands the DNA binding landscape of C/EBP(CAAT enhancer binding protein ) without affecting its expression or activation. The data indicate that Prep1 normally acts by restricting DNA binding of transcription factors to adipogenic enhancers, in particular C/EBP.
Project description:Prep1 is a tumor-suppressor, whereas Meis1 is an oncogene. We show that to perform these activities in MEFs both proteins competitively hetero-dimerize with Pbx1. Meis1 alone transforms Prep1-deficient fibroblasts while Prep1 overexpression inhibits Meis1 tumorigenicity. Pbx1 can therefore alternatively act as oncogene or tumor-suppressor. Prep1 post-translationally controls the level of Meis1 decreasing its stability by sequestering Pbx1. The different levels of Meis1 and the presence of Prep1 are followed at the transcriptional level by the induction of specific transcriptional signatures. The decrease of Meis1 prevents Meis1 interaction with Ddx3x and Ddx5, which are essential for Meis1 tumorigenesis, and modifies the growth promoting DNA binding landscape of Meis1 to the growth controlling landscape of Prep1. Hence the key feature of Prep1 tumor inhibiting activity is the control of Meis1 stability. Examination of Prep1 and Meis1 in three cell type
Project description:Prep1 is a tumor-suppressor, whereas Meis1 is an oncogene. We show that to perform these activities in MEFs both proteins competitively hetero-dimerize with Pbx1. Meis1 alone transforms Prep1-deficient fibroblasts while Prep1 overexpression inhibits Meis1 tumorigenicity. Pbx1 can therefore alternatively act as oncogene or tumor-suppressor. Prep1 post-translationally controls the level of Meis1 decreasing its stability by sequestering Pbx1. The different levels of Meis1 and the presence of Prep1 are followed at the transcriptional level by the induction of specific transcriptional signatures. The decrease of Meis1 prevents Meis1 interaction with Ddx3x and Ddx5, which are essential for Meis1 tumorigenesis, and modifies the growth promoting DNA binding landscape of Meis1 to the growth controlling landscape of Prep1. Hence the key feature of Prep1 tumor inhibiting activity is the control of Meis1 stability. Examination of Prep1 and Meis1 in two cell types
Project description:Prep1 is a tumor-suppressor, whereas Meis1 is an oncogene. We show that to perform these activities in MEFs both proteins competitively hetero-dimerize with Pbx1. Meis1 alone transforms Prep1-deficient fibroblasts while Prep1 overexpression inhibits Meis1 tumorigenicity. Pbx1 can therefore alternatively act as oncogene or tumor-suppressor. Prep1 post-translationally controls the level of Meis1 decreasing its stability by sequestering Pbx1. The different levels of Meis1 and the presence of Prep1 are followed at the transcriptional level by the induction of specific transcriptional signatures. The decrease of Meis1 prevents Meis1 interaction with Ddx3x and Ddx5, which are essential for Meis1 tumorigenesis, and modifies the growth promoting DNA binding landscape of Meis1 to the growth controlling landscape of Prep1. Hence the key feature of Prep1 tumor inhibiting activity is the control of Meis1 stability.
Project description:Prep1 is a tumor-suppressor, whereas Meis1 is an oncogene. We show that to perform these activities in MEFs both proteins competitively hetero-dimerize with Pbx1. Meis1 alone transforms Prep1-deficient fibroblasts while Prep1 overexpression inhibits Meis1 tumorigenicity. Pbx1 can therefore alternatively act as oncogene or tumor-suppressor. Prep1 post-translationally controls the level of Meis1 decreasing its stability by sequestering Pbx1. The different levels of Meis1 and the presence of Prep1 are followed at the transcriptional level by the induction of specific transcriptional signatures. The decrease of Meis1 prevents Meis1 interaction with Ddx3x and Ddx5, which are essential for Meis1 tumorigenesis, and modifies the growth promoting DNA binding landscape of Meis1 to the growth controlling landscape of Prep1. Hence the key feature of Prep1 tumor inhibiting activity is the control of Meis1 stability.