61 research outputs found
Un variant clair du Mouflon Corsico-Sarde (Ovis musimon) dû à un allèle au locus B (Brun)
International audienc
Hybridation entre un Mouflon de Corse (Ovis ammon musimon Schreber, 1872) et des brebis de divers génotypes: gènes pour la coloration pigmentaire
International audienc
Hypotrichose congénitale en race bovine normande. I. – Étude descriptive
International audienc
Dynamic Regulation of Tgf-B Signaling by Tif1Îł: A Computational Approach
TIF1Îł (Transcriptional Intermediary Factor 1 Îł) has been implicated in
Smad-dependent signaling by Transforming Growth Factor beta (TGF-β).
Paradoxically, TIF1Îł functions both as a transcriptional repressor or as an
alternative transcription factor that promotes TGF-β signaling. Using
ordinary differential-equation models, we have investigated the effect of
TIF1γ on the dynamics of TGF-β signaling. An integrative model that
includes the formation of transient TIF1Îł-Smad2-Smad4 ternary complexes is
the only one that can account for TGF-β signaling compatible with the
different observations reported for TIF1Îł. In addition, our model predicts
that varying TIF1Îł/Smad4 ratios play a critical role in the modulation of
the transcriptional signal induced by TGF-β, especially for short
stimulation times that mediate higher threshold responses. Chromatin
immunoprecipitation analyses and quantification of the expression of TGF-β
target genes as a function TIF1Îł/Smad4 ratios fully validate this
hypothesis. Our integrative model, which successfully unifies the seemingly
opposite roles of TIF1Îł, also reveals how changing TIF1Îł/Smad4 ratios
affect the cellular response to stimulation by TGF-β, accounting for a
highly graded determination of cell fate
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