scholarly journals Does high-mobility-group non-histone protein HMG 1 interact specifically with histone H1 subfractions?

1979 ◽  
Vol 183 (3) ◽  
pp. 657-662 ◽  
Author(s):  
P D Cary ◽  
K V Shooter ◽  
G H Goodwin ◽  
E W Johns ◽  
J Y Olayemi ◽  
...  

The interaction of the non-histone chromosomal protein HMG (high-mobility group) 1 with histone H1 subfractions was investigated by equilibrium sedimentation and n.m.r. sectroscopy. In contrast with a previous report [Smerdon & Isenberg (1976) Biochemistry 15, 4242–4247], it was found, by using equilibrium-sedimentation analysis, that protein HMG 1 binds to all three histone H1 subfractions CTL1, CTL2, and CTL3, arguing against there being a specific interaction between protein HMG 1 and only two of the subfractions, CTL1 and CTL2. Raising the ionic strength of the solutions prevents binding of protein HMG 1 to total histone H1 and the three subfractions, suggesting that the binding in vitro is simply a non-specific ionic interaction between acidic regions of the non-histone protein and the basic regions of the histone. Protein HMG 1 binds to histone H5 also, supporting this view. The above conclusions are supported by n.m.r. studies of protein HMG 1/histone H1 subfraction mixtures. When the two proteins were mixed, there was little perturbation of the n.m.r. spectra and there was no evidence for specific interaction of protein HMG 1 with any of the subfractions. It therefore remains an open question as to whether protein HMG 1 and histone H1 are complexed together in chromatin.

ASAIO Journal ◽  
2010 ◽  
Vol 56 (3) ◽  
pp. 210-214 ◽  
Author(s):  
Koichi Suda ◽  
Hiroya Takeuchi ◽  
Tomoko Hagiwara ◽  
Taku Miyasho ◽  
Shingo Yamada ◽  
...  

1997 ◽  
Vol 137 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Luca Falciola ◽  
Fabio Spada ◽  
Sabina Calogero ◽  
Gernot Längst ◽  
Renate Voit ◽  
...  

High mobility group 1 (HMG1) protein is an abundant and conserved component of vertebrate nuclei and has been proposed to play a structural role in chromatin organization, possibly similar to that of histone H1. However, a high abundance of HMG1 had also been reported in the cytoplasm and on the surface of mammalian cells. We conclusively show that HMG1 is a nuclear protein, since several different anti-HMG1 antibodies stain the nucleoplasm of cultured cells, and epitope-tagged HMG1 is localized in the nucleus only. The protein is excluded from nucleoli and is not associated to specific nuclear structures but rather appears to be uniformly distributed. HMG1 can bind in vitro to reconstituted core nucleosomes but is not stably associated to chromatin in live cells. At metaphase, HMG1 is detached from condensed chromosomes, contrary to histone H1. During interphase, HMG1 readily diffuses out of nuclei after permeabilization of the nuclear membranes with detergents, whereas histone H1 remains associated to chromatin. These properties exclude a shared function for HMG1 and H1 in differentiated cells, in spite of their similar biochemical properties. HMG1 may be stably associated only to a very minor population of nucleosomes or may interact transiently with nucleosomes during dynamic processes of chromatin remodeling.


2018 ◽  
Vol 41 (4) ◽  
pp. 190-200
Author(s):  
Ryusuke Amemiya ◽  
Masahiro Shinoda ◽  
Masayuki Yamada ◽  
Yoshiyuki Ueno ◽  
Kaoru Shimada ◽  
...  

Background: High-mobility-group box chromosomal protein 1 has been identified as an important mediator of various kinds of acute and chronic inflammation. In this study, we aimed to develop a column that effectively adsorbs high-mobility-group box chromosomal protein 1 by altering the pore size of the fiber. Materials and methods: First, we produced three types of porous polymethylmethacrylate fiber by altering the concentration of polymethylmethacrylate dissolved in dimethylsulfoxide. We then selected a fiber based on the results of an in vitro incubation test of high-mobility-group box chromosomal protein 1 adsorption. Using the selected fiber, we constructed a new column and tested its high-mobility-group box chromosomal protein 1 adsorption capacity during 4-h extracorporeal hemoperfusion in a swine acute liver failure model. Results: Electron microscope observation showed that the three types of fibers had different pore sizes on the surface and in cross section, which were dependent on the concentration of polymethylmethacrylate. In the in vitro incubation test, fiber with moderate-sized pores demonstrated the highest adsorption capacity. In the in vivo hemoperfusion study, the ratio of the high-mobility-group box chromosomal protein 1 concentration at the outlet versus the inlet of the column was significantly lower with the new column than with the control column during 4-h extracorporeal hemoperfusion. The normalized plasma level of high-mobility-group box chromosomal protein 1 at 12 h after the completion of hemoperfusion was significantly lower with the new column than with the control column. Conclusion: The newly developed polymethylmethacrylate column adsorbs high-mobility-group box chromosomal protein 1 during hemoperfusion in swine ALF model.


1989 ◽  
Vol 9 (5) ◽  
pp. 2114-2123
Author(s):  
K R Johnson ◽  
D A Lehn ◽  
R Reeves

The high-mobility-group protein HMG-I is a well-characterized nonhistone chromosomal protein that is preferentially expressed in rapidly dividing cells, binds to A. T-rich regions of DNA in vitro, and has been localized to particular regions of mammalian metaphase chromosomes. We isolated eight cDNA clones encoding HMG-I and its isoform HMG-Y from a human Raji cell cDNA library and detected blocks of nucleotide sequence rearrangements in the 5'-untranslated regions of these clones. In addition to this leader sequence variation, five of the eight cDNA clones had either a 33- or 36-base-pair in-frame deletion in their open reading frame (ORF); we found that this shortened ORF encodes the HMG-Y protein isoform. We present evidence that the 5'-untranslated-region and ORF heterogeneity of the cDNA clones is the result of alternative processing of RNA transcripts from a single functional gene. Several additional but probably nonfunctional HMG-I or HMG-Y gene copies exist in the human genome; we isolated and partially sequenced one of these pseudogenes and found that it is a processed HMG-Y retropseudogene.


1989 ◽  
Vol 9 (5) ◽  
pp. 2114-2123 ◽  
Author(s):  
K R Johnson ◽  
D A Lehn ◽  
R Reeves

The high-mobility-group protein HMG-I is a well-characterized nonhistone chromosomal protein that is preferentially expressed in rapidly dividing cells, binds to A. T-rich regions of DNA in vitro, and has been localized to particular regions of mammalian metaphase chromosomes. We isolated eight cDNA clones encoding HMG-I and its isoform HMG-Y from a human Raji cell cDNA library and detected blocks of nucleotide sequence rearrangements in the 5'-untranslated regions of these clones. In addition to this leader sequence variation, five of the eight cDNA clones had either a 33- or 36-base-pair in-frame deletion in their open reading frame (ORF); we found that this shortened ORF encodes the HMG-Y protein isoform. We present evidence that the 5'-untranslated-region and ORF heterogeneity of the cDNA clones is the result of alternative processing of RNA transcripts from a single functional gene. Several additional but probably nonfunctional HMG-I or HMG-Y gene copies exist in the human genome; we isolated and partially sequenced one of these pseudogenes and found that it is a processed HMG-Y retropseudogene.


1999 ◽  
Vol 19 (4) ◽  
pp. 2803-2816 ◽  
Author(s):  
Eliette Bonnefoy ◽  
Marie-Thérèse Bandu ◽  
Janine Doly

ABSTRACT The high-mobility-group I (HMGI) protein is a nonhistone component of active chromatin. In this work, we demonstrate that HMGI protein specifically binds to the AT-rich region of the murine beta interferon (IFN-β) promoter localized upstream of the murine virus-responsive element (VRE). Contrary to what has been described for the human promoter, HMGI protein did not specifically bind to the VRE of the murine IFN-β promoter. Stably transfected promoters carrying mutations on this HMGI binding site displayed delayed virus-induced kinetics of transcription. When integrated into chromatin, the mutated promoter remained repressed and never reached normal transcriptional activity. Such a phenomenon was not observed with transiently transfected promoters upon which chromatin was only partially reconstituted. Using UV footprinting, we show that the upstream AT-rich sequences of the murine IFN-β promoter constitute a preferential binding region for histone H1. Transfection with a plasmid carrying scaffold attachment regions as well as incubation with distamycin led to the derepression of the IFN-β promoter stably integrated into chromatin. In vitro, HMGI protein was able to displace histone H1 from the upstream AT-rich region of the wild-type promoter but not from the promoter carrying mutations on the upstream high-affinity HMGI binding site. Our results suggest that the binding of histone H1 to the upstream AT-rich region of the promoter might be partly responsible for the constitutive repression of the promoter. The displacement by HMGI protein of histone H1 could help to convert the IFN-β promoter from a repressed to an active state.


2021 ◽  
pp. 194589242199814
Author(s):  
Soo-Hyung Lee ◽  
Jae Hoon Cho ◽  
Joo-Hoo Park ◽  
Jung-Sun Cho ◽  
Heung-Man Lee

Background Chronic rhinosinusitis is involved in myofibroblast differentiation and extracellular matrix (ECM) accumulation. High mobility group box chromosomal protein 1 (HMGB-1) is known to stimulate lung fibroblast to produce ECM in lung fibrosis. The aim of this study was to investigate whether HMGB-1 induces myofibroblast differentiation and ECM production in nasal fibroblasts and to identify the signal pathway. Methods Human nasal fibroblasts were cultured. After stimulation with HMGB-1, expressions of α-smooth muscle actin (α-SMA) and fibronectin were determined by real-time PCR and western blot. Total collagen was measured by Sircol assay. To investigate signal pathway, various signal inhibitors and RAGE siRNA were used. Results HMGB-1 increased α-SMA and fibronectin in mRNA and protein levels. It also increased collagen production. RAGE siRNA inhibited HMGB-1-induced α-SMA and fibronectin, and production of collagen. Furthermore, the inhibitors of RAGE downstream molecules such as p38, JNK and AP-1 also blocked the HMGB-1-induced effects. Conclusions HMGB-1 induces myofibroblast differentiation and ECM production in nasal fibroblast, which is mediated by RAGE, p38, JNK and AP-1 signal pathway. These results suggest that HMGB-1 may play an important role in tissue remodeling during chronic rhinosinusitis progression.


2021 ◽  
Vol 14 (6) ◽  
pp. 558
Author(s):  
Verena Peek ◽  
Lois M. Harden ◽  
Jelena Damm ◽  
Ferial Aslani ◽  
Stephan Leisengang ◽  
...  

High mobility group box (HMGB)1 action contributes to late phases of sepsis, but the effects of increased endogenous plasma HMGB1 levels on brain cells during inflammation are unclear. Here, we aimed to further investigate the role of HMGB1 in the brain during septic-like lipopolysaccharide-induced inflammation in rats (LPS, 10 mg/kg, i.p.). HMGB-1 mRNA expression and release were measured in the periphery/brain by RT-PCR, immunohistochemistry and ELISA. In vitro experiments with disulfide-HMGB1 in primary neuro-glial cell cultures of the area postrema (AP), a circumventricular organ with a leaky blood–brain barrier and direct access to circulating mediators like HMGB1 and LPS, were performed to determine the direct influence of HMGB1 on this pivotal brain structure for immune-to-brain communication. Indeed, HMGB1 plasma levels stayed elevated after LPS injection. Immunohistochemistry of brains and AP cultures confirmed LPS-stimulated cytoplasmatic translocation of HMGB1 indicative of local HMGB1 release. Moreover, disulfide-HMGB1 stimulation induced nuclear factor (NF)-κB activation and a significant release of interleukin-6, but not tumor necrosis factor α, into AP culture supernatants. However, only a few AP cells directly responded to HMGB1 with increased intracellular calcium concentration. Interestingly, priming with LPS induced a seven-fold higher percentage of responsive cells to HMGB1. We conclude that, as a humoral and local mediator, HMGB1 enhances brain inflammatory responses, after LPS priming, linked to sustained sepsis symptoms.


2005 ◽  
Vol 19 (7) ◽  
pp. 1884-1892 ◽  
Author(s):  
Helena Sim ◽  
Kieran Rimmer ◽  
Sabine Kelly ◽  
Louisa M. Ludbrook ◽  
Andrew H. A. Clayton ◽  
...  

Abstract The sex-determining region of the Y chromosome (SRY) plays a key role in human sex determination, as mutations in SRY can cause XY sex reversal. Although some SRY missense mutations affect DNA binding and bending activities, it is unclear how others contribute to disease. The high mobility group domain of SRY has two nuclear localization signals (NLS). Sex-reversing mutations in the NLSs affect nuclear import in some patients, associated with defective importin-β binding to the C-terminal NLS (c-NLS), whereas in others, importin-β recognition is normal, suggesting the existence of an importin-β-independent nuclear import pathway. The SRY N-terminal NLS (n-NLS) binds calmodulin (CaM) in vitro, and here we show that this protein interaction is reduced in vivo by calmidazolium, a CaM antagonist. In calmidazolium-treated cells, the dramatic reduction in nuclear entry of SRY and an SRY-c-NLS mutant was not observed for two SRY-n-NLS mutants. Fluorescence spectroscopy studies reveal an unusual conformation of SRY.CaM complexes formed by the two n-NLS mutants. Thus, CaM may be involved directly in SRY nuclear import during gonadal development, and disruption of SRY.CaM recognition could underlie XY sex reversal. Given that the CaM-binding region of SRY is well-conserved among high mobility group box proteins, CaM-dependent nuclear import may underlie additional disease states.


2010 ◽  
Vol 37 (4) ◽  
pp. 766-775 ◽  
Author(s):  
JIE LI ◽  
HONGFU XIE ◽  
TING WEN ◽  
HONGBO LIU ◽  
WU ZHU ◽  
...  

Objective.To compare the expression of high mobility group box chromosomal protein 1 (HMGB1) and the modulating effects on its downstream cytokines in patients with systemic lupus erythematosus (SLE) and healthy controls.Methods.HMGB1 concentrations in serum from SLE patients and controls were measured by immunoblot analysis. HMGB1 messenger RNA (mRNA) expression in peripheral blood mononuclear cells (PBMC) was detected by real-time reverse transcription–polymerase chain reaction. Immunofluorescence assay was employed to examine the translocation of HMGB1 in monocytes after endotoxin stimulation. Release of tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6) by PBMC after rHMGB1 stimulation was also measured.Results.Serum HMGB1 levels and HMGB1 mRNA expressions in PBMC were elevated in SLE patients compared with controls. A positive correlation was demonstrated between HMGB1 concentrations and SLE Disease Activity Index. There was an inverse correlation between HMGB1 levels and C4 and C3 concentrations in SLE patients. HMGB1 concentrations were higher in patients with vasculitis and myositis. Lipopolysaccharide stimulated a temporarily elevated release of HMGB1 in SLE patients compared with controls. The pattern and localization of HMGB1 staining in monocytes were similar in both groups. After stimulation with rHMGB1, TNF-α level decreased but IL-6 level increased in SLE patients compared with controls.Conclusion.Our findings suggest that increased serum levels of HMGB1 in SLE may be associated with lupus disease activity. The altered production of TNF-α and IL-6 in response to rHMGB1 stimulation may participate in the disruption of cytokine homeostasis in SLE.


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