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Chromatin Regulation (chromatin + regulation)
Selected AbstractsMRG15, a component of HAT and HDAC complexes, is essential for proliferation and differentiation of neural precursor cellsJOURNAL OF NEUROSCIENCE RESEARCH, Issue 7 2009Meizhen Chen Abstract Neurogenesis during development depends on the coordinated regulation of self-renewal and differentiation of neural precursor cells (NPCs). Chromatin regulation is a key step in self-renewal activity and fate decision of NPCs. However, the molecular mechanism or mechanisms of this regulation is not fully understood. Here, we demonstrate for the first time that MRG15, a chromatin regulator, is important for proliferation and neural fate decision of NPCs. Neuroepithelia from Mrg15 -deficient embryonic brain are much thinner than those from control, and apoptotic cells increase in this region. We isolated NPCs from Mrg15 -deficient and wild-type embryonic whole brains and produced neurospheres to measure the self-renewal and differentiation abilities of these cells in vitro. Neurospheres culture from Mrg15 -deficient embryo grew less efficiently than those from wild type. Measurement of proliferation by means of BrdU (bromodeoxyuridine) incorporation revealed that Mrg15 -deficient NPCs have reduced proliferation ability and apoptotic cells do not increase during in vitro culture. The reduced proliferation of Mrg15 -deficient NPCs most likely accounts for the thinner neuroepithelia in Mrg15 -deficient embryonic brain. Moreover, we also demonstrate Mrg15 -deficient NPCs are defective in differentiation into neurons in vitro. Our results demonstrate that MRG15 has more than one function in neurogenesis and defines a novel role for this chromatin regulator that integrates proliferation and cell-fate determination in neurogenesis during development. © 2008 Wiley-Liss, Inc. [source] Single-molecule analysis of chromatin: Changing the view of genomes one molecule at a timeJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2008Santhi Pondugula Abstract Wrapping DNA into chromatin provides a wealth of regulatory mechanisms that ensure normal growth and development in eukaryotes. Our understanding of chromatin structure, including nucleosomes and non-histone protein,DNA interactions, has benefited immensely from nuclease and chemical digestion techniques. DNA-bound proteins, such as histones or site-specific factors, protect DNA against nuclease cleavage and generate large nucleosomal or small regulatory factor footprints. Chromatin subject to distinct modes of regulation often coincides with sites of nuclease hypersensitivity or nucleosome positioning. An inherent limitation of cleavage-based analyses has been the inability to reliably analyze regions of interest when levels of digestion depart from single-hit kinetics. Moreover, cleavage-based techniques provide views that are averaged over all the molecules in a sample population. Therefore, in cases of occupancy of multiple regulatory elements by factors, one cannot define whether the factors are bound to the same or different molecules in the population. The recent development of DNA methyltransferase-based, single-molecule MAP-IT technology overcomes limitations of ensemble approaches and has opened numerous new avenues in chromatin research. Here, we review the strengths, limitations, applications and future prospects of MAP-IT ranging from structural issues to mechanistic questions in eukaryotic chromatin regulation. J. Cell. Biochem. 105: 330,337, 2008. © 2008 Wiley-Liss, Inc. [source] Chromatin regulation functions in plant abiotic stress responsesPLANT CELL & ENVIRONMENT, Issue 4 2010JONG-MYONG KIM ABSTRACT Plants respond and adapt to drought, cold and high-salinity stress in order to survive. Molecular and genomic studies have revealed that many stress-inducible genes with various functions and signalling factors, such as transcription factors, protein kinases and protein phosphatases, are involved in the stress responses. Recent studies have revealed the coordination of the gene expression and chromatin regulation in response to the environmental stresses. Several histone modifications are dramatically altered on the stress-responsive gene regions under drought stress conditions. Several chromatin-related proteins such as histone modification enzymes, linker histone H1 and components of chromatin remodeling complex influence the gene regulation in the stress responses. This review briefly describes chromatin regulation in response to drought, cold and high-salinity stress. [source] Immune subversion by chromatin manipulation: a ,new face' of host,bacterial pathogen interactionCELLULAR MICROBIOLOGY, Issue 8 2008Laurence Arbibe Summary Bacterial pathogens have evolved various strategies to avoid immune surveillance, depending of their in vivo,lifestyle'. The identification of few bacterial effectors capable to enter the nucleus and modifying chromatin structure in host raises the fascinating questions of how pathogens modulate chromatin structure and why. Chromatin is a dynamic structure that maintains the stability and accessibility of the host DNA genome to the transcription machinery. This review describes the various strategies used by pathogens to interface with host chromatin. In some cases, chromatin injury can be a strategy to take control of major cellular functions, such as the cell cycle. In other cases, manipulation of chromatin structure at specific genomic locations by modulating epigenetic information provides a way for the pathogen to impose its own transcriptional signature onto host cells. This emerging field should strongly influence our understanding of chromatin regulation at interphase nucleus and may provide invaluable openings to the control of immune gene expression in inflammatory and infectious diseases. [source] | ||||||||||