14 research outputs found
The X-inactivation trans-activator Rnf12 is negatively regulated by pluripotency factors in embryonic stem cells
X-inactivation, the molecular mechanism enabling dosage compensation in mammals, is tightly controlled during mouse early embryogenesis. In the morula, X-inactivation is imprinted with exclusive silencing of the paternally inherited X-chromosome. In contrast, in the post-implantation epiblast, X-inactivation affects randomly either the paternal or the maternal X-chromosome. The transition from imprinted to random X-inactivation takes place in the inner cell mass (ICM) of the blastocyst from which embryonic stem (ES) cells are derived. The trigger of X-inactivation, Xist, is specifically downregulated in the pluripotent cells of the ICM, thereby ensuring the reactivation of the inactive paternal X-chromosome and the transient presence of two active X-chromosomes. Moreover, Tsix, a critical cis-repressor of Xist, is upregulated in the ICM and in ES cells where it imposes a particular chromatin state at the Xist promoter that ensures the establishment of random X-inactivation upon differentiation. Recently, we have shown that key transcription factors supporting pluripotency directly repress Xist and activate Tsix and thus couple Xist/Tsix control to pluripotency. In this manuscript, we report that Rnf12, a third X-linked gene critical for the regulation of X-inactivation, is under the control of Nanog, Oct4 and Sox2, the three factors lying at the heart of the pluripotency network. We conclude that in mouse ES cells the pluripotency-associated machinery exerts an exhaustive control of X-inactivation by taking over the regulation of all three major regulators of X-inactivation: Xist, Tsix, and Rnf12
Role of the P6−P3‘ Region of the Serpin Reactive Loop in the Formation and Breakdown of the Inhibitory Complex â€
Heterogeneity in Serpin−Protease Complexes As Demonstrated by Differences in the Mechanism of Complex Breakdown â€
Mast Cell Chymase Modifies Cell-Matrix Interactions and Inhibits Mitogen-Induced Proliferation of Human Airway Smooth Muscle Cells
Topographic Heterogeneity Plays a Crucial Role for Grasshopper Diversity in a Southern African Megabiodiversity Hotspot
Economic Analysis of a Multi-Site Prevention Program: Assessment of Program Costs and Characterizing Site-level Variability
Public Opinion and Dynamic Representation in the American States: The Case of Environmental Attitudes
We investigate causal processes linking environmental conditions, attitudes, and policies in the American states: Is public opinion about ecology shaped by environmental conditions? Are state policymakers responsive to environmental opinions? Does public opinion respond to policy adoption? Copyright (c) 2005 by the Southwestern Social Science Association.