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Silvia Moleri Giuseppe Cappellano Germano Gaudenzi Solei Cermenati Franco Cotelli David S. Horner Monica Beltrame 《Gene expression patterns : GEP》2011,11(1-2):3-11
The High-Mobility Group Box (HMGB) proteins are highly abundant proteins with both nuclear and extracellular roles in key biological processes. In mammals, three family members are present: HMGB1, HMGB2 and HMGB3. We characterized the HMGB family in zebrafish and report a detailed phylogenetic analysis of HMGB proteins. The B1, B2, and B3 subfamilies are present in cartilaginous fish, bony fish, and tetrapods, while jawless fish sequences emerge as basal to the gene family expansion. Two co-orthologs of each mammalian HMGB gene are present in zebrafish. All six zebrafish hmgb genes are maternally expressed, but huge differences in expression levels exist during embryonic development. The hmgb2a/hmgb2b genes are the most highly expressed, while hmgb3b is expressed at the lowest level. Remarkably, hmgb3 genes are not present in fugu, medaka, Tetraodon and stickleback. Our analysis highlights substantial overlaps, but also subtle differences and specificities in the expression patterns of the zebrafish hmgb genes. 相似文献
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Homeodomain proteins and the regulation of gene expression 总被引:21,自引:0,他引:21
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Qinqin Zhuang Hugh Smallman Stanley J. Lambert Sirirath S. Sodngam Colin D. Reynolds Katie Evans Mark J. Dickman John P. Baldwin Christopher M. Wood 《Analytical biochemistry》2014
An effective and flexible method is presented that can be used to investigate cofractionation of groups of nuclear proteins. The method was used to analyze chromatin-related proteins, of which high-mobility group B (HMGB) proteins consistently cofractionated by cation-exchange chromatography with the histone dimer (H2A–H2B). This led to the hypothesis that the two form a complex, further suggested by gel filtration, in which the HMGBs with core histones eluted as a defined high-molecular-weight peak. A necessary requirement for further studying protein interactions is that the constituents are of the highest possible purity and the pure histone dimers and tetramers used in this study were derived from pure histone octamers with their native marks. There is a growing interest in protein–protein interactions and an increasing focus on protein-interaction domains: most frequently, pull-down assays are used to examine these. The technology presented here can provide an effective system that complements pull-down assays. 相似文献
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Cytoplasmic Ca2+ is an universal intracellular messenger that activates cellular responses over a broad temporal range, from neurotransmitter release to cell growth and proliferation.1,2 Inherent to the use of the multifarious Ca2+ signal is the question of specificity: how can some Ca2+-dependent responses be activated in a cell and not others? A rise in cytoplasmic Ca2+ can evoke a response either by binding directly to the target (as occurs with certain Ca2+-activated K+ and Cl− channels, for example) or through recruitment of intermediary proteins, such as calmodulin and troponin C. A substantial body of evidence has now established that Ca2+-binding proteins differ both in their affinities for Ca2+ and in their on- and off-rates for Ca2+ binding/unbinding. Furthermore, different Ca2+-binding proteins often occupy distinct locations within the cell. Therefore, the size, kinetics and spatial profile of a cytoplasmic Ca2+ signal are all important in determining which Ca2+-dependent response will be activated, when and for how long.3 相似文献
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Jingyun Zhang Micah J. McCauley L. James Maher III Mark C. Williams N. E. Israeloff 《Nucleic acids research》2009,37(4):1107-1114
The mechanism by which sequence non-specific DNA-binding proteins enhance DNA flexibility is studied by examining complexes of double-stranded DNA with the high mobility group type B proteins HMGB2 (Box A) and HMGB1 (Box A+B) using atomic force microscopy. DNA end-to-end distances and local DNA bend angle distributions are analyzed for protein complexes deposited on a mica surface. For HMGB2 (Box A) binding we find a mean induced DNA bend angle of 78°, with a standard error of 1.3° and a SD of 23°, while HMGB1 (Box A+B) binding gives a mean bend angle of 67°, with a standard error of 1.3° and a SD of 21°. These results are consistent with analysis of the observed global persistence length changes derived from end-to-end distance measurements, and with results of DNA-stretching experiments. The moderately broad distributions of bend angles induced by both proteins are inconsistent with either a static kink model, or a purely flexible hinge model for DNA distortion by protein binding. Therefore, the mechanism by which HMGB proteins enhance the flexibility of DNA must differ from that of the Escherichia coli HU protein, which in previous studies showed a flat angle distribution consistent with a flexible hinge model. 相似文献
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HMGB1 expression and release by bone cells 总被引:5,自引:0,他引:5
Charoonpatrapong K Shah R Robling AG Alvarez M Clapp DW Chen S Kopp RP Pavalko FM Yu J Bidwell JP 《Journal of cellular physiology》2006,207(2):480-490
Immune and bone cells are functionally coupled by pro-inflammatory cytokine intercellular signaling networks common to both tissues and their crosstalk may contribute to the etiologies of some immune-associated bone pathologies. For example, the receptor activator of NF-kappaB ligand (RANKL)/osteoprotegerin (OPG)/receptor activator of NF-kappaB (RANK) signaling axis plays a critical role in dendritic cell (DC) function as well as bone remodeling. The expression of RANKL by immune cells may contribute to bone loss in periodontitis, arthritis, and multiple myeloma. A recent discovery reveals that DCs release the chromatin protein high mobility group box 1 (HMGB1) as a potent immunomodulatory cytokine mediating the interaction between DCs and T-cells, via HMGB1 binding to the membrane receptor for advanced glycation end products (RAGE). To determine whether osteoblasts or osteoclasts express and/or release HMGB1 into the bone microenvironment, we analyzed tissue, cells, and culture media for the presence of this molecule. Our immunohistochemical and immunocytochemical analyses demonstrate HMGB1 expression in primary osteoblasts and osteoclasts and that both cells express RAGE. HMGB1 is recoverable in the media of primary osteoblast cultures and cultures of isolated osteoclast precursors and osteoclasts. Parathyroid hormone (PTH), a regulator of bone remodeling, attenuates HMGB1 release in cultures of primary osteoblasts and MC3T3-E1 osteoblast-like cells but augments this release in the rat osteosarcoma cell line UMR 106-01, both responses primarily via activation of adenylyl cyclase. PTH-induced HMGB1 discharge by UMR cells exhibits similar release kinetics as reported for activated macrophages. These data confirm the presence of the HMGB1/RAGE signaling axis in bone. 相似文献
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Polycomb group (PcG) complexes maintain epigenetically repressed states that need to be reprogrammed when cells become committed to differentiation. In contrast to the previously held belief that PcG complexes regulate only a few selected genes, recent efforts have revealed hundreds of potential PcG targets in mammals, insects and plants. These results have changed our perception about PcG recruitment and function on chromatin. Both in animals and plants, evolutionarily conserved PcG complexes mark the chromatin of their target genes by methylation at histone H3 lysine 27. Surprisingly, however, both the proteins recognizing this mark and the mechanisms causing gene repression differ between both kingdoms. This suggests that different developmental strategies used in plant and animal development entailed the evolution of different repressive maintenance mechanisms. 相似文献
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Polianichko AM Leonenko ZV Kramb D Vieser G Vorob'ev VI Chikhirzhina EV 《Biofizika》2008,53(3):407-416
The interaction between DNA and the nonhistone proteins HMGB1 and HMGB1-(A+B) has been studied using circular dichroism and scanning force microscopy. The recombinant protein HMGB1-(A+B) has no negatively charged C-terminal domain characteristic for HMGB1. Our earlier suggestion about the structural interaction of tandem HMGB1-domains of the recombinant protein with DNA was confirmed. It was shown that the C-terminal part modulates the interactions of HMGB1-domains with DNA. Without the C-terminal sequence, the HMGB1-(A+B) protein forms DNA-protein complexes with the ordered supramolecular structure. 相似文献
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Association of chromatin proteins high mobility group box (HMGB) 1 and HMGB2 with mitotic chromosomes 总被引:8,自引:0,他引:8
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Pallier C Scaffidi P Chopineau-Proust S Agresti A Nordmann P Bianchi ME Marechal V 《Molecular biology of the cell》2003,14(8):3414-3426
High mobility group box (HMGB) 1 and 2 are two abundant nonhistone nuclear proteins that have been found in association with chromatin. Previous studies based on immunofluorescence analysis indicated that HMGB1 dissociates from chromosomes during mitosis. In the present work, HMGB1 and 2 subcellular localization was reinvestigated in living cells by using enhanced green fluorescent protein- and Discosome sp. red fluorescent protein-tagged proteins. Contrary to previous reports, HMGB1 and 2 were shown to be present under two forms in mitotic cells, i.e., free and associated with the condensed chromatin, which rapidly exchange. A detailed analysis of HMGB2 interaction with mitotic chromosomes indicated that two sites encompassing HMG-box A and B are responsible for binding. Importantly, this interaction was rapidly inactivated when cells were permeabilized or exposed to chemical fixatives that are widely used in immunodetection techniques. A comparable behavior was also observed for two proteins of the HMG-nucleosome binding (HMGN) group, namely, HMGN1 and HMGN2. 相似文献
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Histone-like proteins in bacteria contribute to the control of gene expression, as well as participating in other DNA transactions such as recombination and DNA replication. They have also been described, somewhat vaguely, as contributors to the organization of the bacterial nucleoid. Our view of how these proteins act in the cell is becoming clearer, particularly in the cases of Fis, H-NS and HU, three of the most intensively studied members of the group. Especially helpful have been studies of the contributions of these proteins to the regulation of specific genes such as the gal operon, and genes coding for stable RNA species, topoisomerases, and the histone-like proteins themselves. Recent advances have also been assisted by insights into the effects the histone-like proteins exert on DNA structure not only at specific promoters but throughout the genome. 相似文献
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《Gene》1998,221(2):279-285
The regulation of gene expression by the tetracycline system has attracted a high level of interest in the recent past. However, expression of secreted proteins has not been evaluated precisely. In this study, we constructed two versions of a one-plasmid system containing the elements necessary for the regulation of gene expression. The regulatable elements and the selectable marker (Neor) were set up in two different configurations, pTRIN31 and pTRIN76. With these two regulatable versions, the levels of protein expression after transfection into the NIH/3T3 cell line were measured by insertion of three different genes encoding the secreted proteins (hGH, ApoE3, hGM-CSF). The maximum levels of gene expression obtained with the pTRIN76-derived plasmids were 100 ng/24 h/106 cells for hGH, 427 ng/24 h/106 cells for ApoE3 and 108 ng/24 h/106 cells for hGM-CSF. For the pTRIN31-derived plasmids the maximum levels were 2.7 ng/24 h/106 cells for hGH and 47 ng/24 h/106 for ApoE3. Both plasmids give rise to an expression of the transfected gene that can be tightly regulated by three different molecules: tetracycline, minocycline and doxycycline. The levels of the secreted proteins are below the detectable level when the reporter genes are repressed. This repression is reversible within 48 h after the regulator has been removed from the medium. 相似文献