scholarly journals Network of Dynamic Interactions between Histone H1 and High-Mobility-Group Proteins in Chromatin

2004 ◽  
Vol 24 (10) ◽  
pp. 4321-4328 ◽  
Author(s):  
Frédéric Catez ◽  
Huan Yang ◽  
Kevin J. Tracey ◽  
Raymond Reeves ◽  
Tom Misteli ◽  
...  
Keyword(s):  
Binding Sites ◽  
High Mobility ◽  
Histone H1 ◽  
Chromatin Fiber ◽  
High Mobility Group ◽  
Chromatin Binding ◽  
Hmg Proteins ◽  
Dynamic Interactions ◽  
Regulate Gene Expression ◽  
Regulatory Factors

ABSTRACT Histone H1 and the high-mobility group (HMG) proteins are chromatin binding proteins that regulate gene expression by modulating the compactness of the chromatin fiber and affecting the ability of regulatory factors to access their nucleosomal targets. Histone H1 stabilizes the higher-order chromatin structure and decreases nucleosomal access, while the HMG proteins decrease the compactness of the chromatin fiber and enhance the accessibility of chromatin targets to regulatory factors. Here we show that in living cells, each of the three families of HMG proteins weakens the binding of H1 to nucleosomes by dynamically competing for chromatin binding sites. The HMG families weaken H1 binding synergistically and do not compete among each other, suggesting that they affect distinct H1 binding sites. We suggest that a network of dynamic and competitive interactions involving HMG proteins and H1, and perhaps other structural proteins, constantly modulates nucleosome accessibility and the local structure of the chromatin fiber.

scholarly journals The dynamics of HMG protein–chromatin interactions in living cellsThis paper is one of a selection of papers published in this Special Issue, entitled CSBMCB’s 51st Annual Meeting – Epigenetics and Chromatin Dynamics, and has undergone the Journal’s usual peer review process.

2009 ◽  
Vol 87 (1) ◽  
pp. 127-137 ◽  
Author(s):  
Gabi Gerlitz ◽  
Robert Hock ◽  
Tetsuya Ueda ◽  
Michael Bustin
Keyword(s):  
Binding Sites ◽  
Binding Proteins ◽  
Peer Review Process ◽  
High Mobility ◽  
Structural Features ◽  
Chromatin Binding ◽  
Hmg Proteins ◽  
Chromatin Dynamics ◽  
Chromatin Interactions ◽  
Major Factors

The dynamic interaction between nuclear proteins and chromatin leads to the functional plasticity necessary to mount adequate responses to regulatory signals. Here, we review the factors regulating the chromatin interactions of the high mobility group proteins (HMGs), an abundant and ubiquitous superfamily of chromatin-binding proteins in living cells. HMGs are highly mobile and interact with the chromatin fiber in a highly dynamic fashion, as part of a protein network. The major factors that affect the binding of HMGs to chromatin are operative at the level of the single nucleosome. These factors include structural features of the HMGs, competition with other chromatin-binding proteins for nucleosome binding sites, complex formation with protein partners, and post-translational modifications in the protein or in the chromatin-binding sites. The versatile modulation of the interaction between HMG proteins and chromatin plays a role in processes that establish the cellular phenotype.

scholarly journals High-mobility-group (HMG) proteins and histone H1 subtypes expression in normal and tumor tissues of mouse

1993 ◽  
Vol 213 (2) ◽  
pp. 825-832 ◽  
Author(s):  
Vincenzo GIANCOTTI ◽  
Antonella BANDIERA ◽  
Lorenza CIANI ◽  
Daniela SANTORO ◽  
Colyn CRANE-ROBINSON ◽  
...  
Keyword(s):  
High Mobility ◽  
Histone H1 ◽  
High Mobility Group ◽  
Hmg Proteins ◽  
Tumor Tissues

scholarly journals Tetrahymena contain two distinct and unusual high mobility group (HMG)-like proteins.

1987 ◽  
Vol 104 (6) ◽  
pp. 1485-1494 ◽  
Author(s):  
I G Schulman ◽  
R G Cook ◽  
R Richman ◽  
C D Allis
Keyword(s):  
Polyclonal Antibodies ◽  
High Mobility ◽  
Histone H1 ◽  
High Mobility Group ◽  
Hmg Proteins ◽  
Terminal Sequence ◽  
Amino Terminal ◽  
Calf Thymus ◽  
Specific Induction ◽  
Amino Terminal Sequence

Previous studies have described the existence of high mobility group (HMG)-like proteins in macronuclei of the ciliated protozoan, Tetrahymena thermophila (Hamana, K., and K. Iwai, 1979, J. Biochem. [Tokyo], 69:1097-1111; Levy-Wilson, B., M. S. Denker, and E. Ito, 1983, Biochemistry, 22:1715-1721). In this report, two of these proteins, LG-1 and LG-2, have been further characterized. Polyclonal antibodies raised against LG-1 and LG-2 fail to cross react with each other or any other macronuclear polypeptide in immunoblotting analyses. As well, LG-1 and LG-2 antibodies do not react with calf thymus, chicken, or yeast HMG proteins. Consistent with these results, a 47 amino-terminal sequence of LG-1 has been determined that shows limited homology to both calf thymus HMGs 1 and 2 and HMGs 14 and 17. Two internal sequences of V8 protease-generated peptides from LG-2 have been determined, and these do not share any homology to the LG-1 sequence or any other sequenced HMG proteins. Comparison of the partial sequences of LG-1 and LG-2 with the complete amino acid sequence of the Tetrahymena histone H1 (Wu, M., C. D. Allis, R. Richman, R. G. Cook, and M. A. Gorovsky, 1986, Proc. Natl. Acad. Sci. USA, 83:8674-8678) rules out the possibility that LG-1 and LG-2 are proteolytically derived from H1, the other major macronuclear perchloric acid-soluble protein. Interestingly, however, both LG-1 and LG-2 are efficiently extracted from macronuclei by elutive intercalation (Schröter, H., G. Maier, H. Ponsting, and A. Nordheim, 1985, Embo (Eur. Mol. Biol. Organ.) J., 4:3867-3872), suggesting that both may share yet undetermined properties with HMGs 14 and 17 of higher eukaryotes. Examination of the pattern of LG-1 and LG-2 synthesis during the sexual phase of the life cycle, conjugation, demonstrates that the synthesis of LG-1 and LG-2 is coordinately increased from basal levels during the differentiation of new macronuclei (7-13 h), suggesting that both of these proteins play a role in determining a macronuclear phenotype. However, a specific induction of LG-2 synthesis is detected in early stages of conjugation (meiotic prophase, 1-4 h), leading to maximal synthesis of LG-2 at 3 h. Interestingly, the early induction of LG-2 synthesis closely parallels the hyperphosphorylation of histone H1. Taken together, these data suggest that LG-1 and LG-2 are not strongly related to each other or to higher eukaryotic HMG proteins.(ABSTRACT TRUNCATED AT 400 WORDS)

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 ◽  
...  
Keyword(s):  
Specific Interaction ◽  
High Mobility ◽  
Histone H1 ◽  
High Mobility Group ◽  
Chromosomal Protein ◽  
Histone Protein ◽  
Total Histone ◽  
Equilibrium Sedimentation ◽  
Histone H5

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.

scholarly journals Phosphorylation of high mobility group 1 protein by phospholipid-sensitive Ca2+-dependent protein kinase from pig testis

1985 ◽  
Vol 227 (1) ◽  
pp. 271-276 ◽  
Author(s):  
K Kimura ◽  
N Katoh ◽  
K Sakurada ◽  
S Kubo
Keyword(s):  
Protein Kinase ◽  
High Mobility ◽  
Particulate Fraction ◽  
High Mobility Group ◽  
Hmg Proteins ◽  
Dependent Protein Kinase ◽  
Histone Proteins ◽  
Km Value ◽  
Dependent Protein ◽  
Group 1

Phospholipid-sensitive Ca2+-dependent protein kinase was partially purified from total particulate fraction of pig testis. The enzyme phosphorylated high mobility group 1 protein (HMG 1), one of the major chromatin-associated non-histone proteins. Other HMG proteins (HMG 2, 14 and 17) were not phosphorylated by the enzyme. Exhaustive phosphorylation of HMG 1 revealed that 1 mol of phosphate was incorporated/mol of HMG 1. The apparent Km value for HMG 1 was 3.66 microM. 1,3-Diolein stimulated the phosphorylation at 10 microM-Ca2+ in the presence of phosphatidylserine. The phosphorylation of HMG 1 was inhibited by adriamycin, an inhibitor of spermatogenesis.

scholarly journals Concentrations of high-mobility-group proteins in the nucleus and cytoplasm of several rat tissues.

1984 ◽  
Vol 99 (2) ◽  
pp. 648-654 ◽  
Author(s):  
L Kuehl ◽  
B Salmond ◽  
L Tran
Keyword(s):  
High Mobility ◽  
High Mobility Group ◽  
Rat Tissues ◽  
Two Dimensional ◽  
Hmg Proteins ◽  
High Mobility Group Proteins

Nuclear and cytoplasmic fractions were isolated from various tissues of the rat by a nonaqueous technique. The high-mobility-group (HMG) proteins were extracted from these fractions with acid and separated by one- and two-dimensional PAGE. The concentrations of high-mobility-group proteins HMG1, HMG2, and HMG17 in the nucleus and cytoplasm were then estimated from the staining intensities of the electrophoretic bands. The cytoplasmic concentrations of these proteins were very low--usually less than 1/30 of those present in the corresponding nuclear fractions. For the tissues studied (liver, kidney, heart, and lung), the concentrations of HMG proteins in the nucleus did not differ significantly from one tissue to another. Averaged over the four tissues investigated, there were 0.28 molecule of HMG1, 0.18 molecule of HMG2, and 0.46 molecule of HMG17 per nucleosome. These values are considerably higher than those that have been reported previously.

scholarly journals High mobility group proteins of amphibian oocytes: a large storage pool of a soluble high mobility group-1-like protein and involvement in transcriptional events.

1983 ◽  
Vol 97 (3) ◽  
pp. 838-848 ◽  
Author(s):  
J A Kleinschmidt ◽  
U Scheer ◽  
M C Dabauvalle ◽  
M Bustin ◽  
W W Franke
Keyword(s):  
Rana Temporaria ◽  
Peptide Mapping ◽  
Gradient Centrifugation ◽  
High Mobility ◽  
High Mobility Group ◽  
Monomeric Form ◽  
Hmg Proteins ◽  
Amphibian Species ◽  
Large Oocyte ◽  
Calf Thymus

Oocytes of several amphibian species (Xenopus laevis, Rana temporaria, and Pleurodeles waltlii) contained a relatively large pool of nonchromatin-bound, soluble high mobility group (HMG) protein with properties similar to those of calf thymus proteins HMG-1 and HMG-2 (protein HMG-A; A, amphibian). About half of this soluble HMG-A was located in the nuclear sap, the other half was recovered in enucleated ooplasms. This protein was identified by its mobility on one- and two-dimensional gel electrophoresis, by binding of antibodies to calf thymus HMG-1 to polypeptides electrophoretically separated and blotted on nitrocellulose paper, and by tryptic peptide mapping of radioiodinated polypeptides. Most, if not all, of the HMG-A in the soluble nuclear protein fraction, preparatively defined as supernatant obtained after centrifugation at 100,000 g for 1 h, was in free monomeric form, apparently not bound to other proteins. On gel filtration it eluted with a mean peak corresponding to an apparent molecular weight of approximately 25,000; on sucrose gradient centrifugation it appeared with a very low S value (2-3 S), and on isoelectric focusing it appeared in fractions ranging from pH approximately 7 to 9. This soluble HMG-A was retained on DEAE-Sephacel but could be eluted already at moderate salt concentrations (0.2 M KCl). In oocytes of various stages of oogenesis HMG-A was accumulated in the nucleus up to concentrations of approximately 14 ng per nucleus (in Xenopus), corresponding to approximately 0.2 mg/ml, similar to those of the nucleosomal core histones. This nuclear concentration is also demonstrated using immunofluorescence microscopy. When antibodies to bovine HMG-1 were microinjected into nuclei of living oocytes of Pleurodeles the lateral loops of the lampbrush chromosomes gradually retracted and the whole chromosomes condensed. As shown using electron microscopy of spread chromatin from such injected oocyte nuclei, this process of loop retraction was accompanied by the appearance of variously-sized and irregularly-spaced gaps within transcriptional units of chromosomal loops but not of nucleoli, indicating that the transcription of non-nucleolar genes was specifically inhibited by this treatment and hence involved an HMG-1-like protein. These data show that proteins of the HMG-1 and -2 category, which are usually chromatin-bound components, can exist, at least in amphibian oocytes, in a free soluble monomeric form, apparently not bound to other molecules. The possible role of this large oocyte pool of soluble HMG-A in early embryogenesis is discussed as well as the possible existence of soluble HMG proteins in other cells.

scholarly journals Changes in quantities of high-mobility-group protein 1 in oviduct cellular fractions after oestrogen stimulation

1981 ◽  
Vol 198 (1) ◽  
pp. 85-90 ◽  
Author(s):  
C T Teng ◽  
C S Teng
Keyword(s):  
Microsomal Fraction ◽  
High Mobility ◽  
Quantitative Change ◽  
High Mobility Group ◽  
Nuclear Fraction ◽  
Hmg Proteins ◽  
High Mobility Group Protein ◽  
Group Protein ◽  
Oviduct Cell

Antiserum against chick oviduct high-mobility-group protein 1 (HMG 1) has been induced in the rabbit. With this antiserum, immunobiochemical techniques have been used to probe the quantitative change of HMG 1 in the cellular fractions of chick oviduct before or after oestrogen stimulation. HMG 1 is detectable in the cytosol, microsomal and nuclear fraction of the chick oviduct cell. After administration of oestrogen to young chicks in vivo for 5 days, the quantity of HMG 1 is increased 4-fold in the cytosol, 3.5-fold in the microsomal fraction and 1.6-fold in the nuclear fraction. The finding of large amounts of HMG 1 in cytoplasm of oviduct cell is not likely due to its leakage from the nucleus. We anticipate that HMG 1 is synthesized in the cytoplasm and then transported into the nucleus. The synthesis and transportation of HMG proteins is probably regulated by oestrogen.

Analysis of putative high-mobility-group (HMG) proteins in neuronal and glial nuclei from rabbit brain

1981 ◽  
Vol 6 (6) ◽  
pp. 673-679 ◽  
Author(s):  
Paul Greenwood ◽  
Julie C. Silver ◽  
Ian R. Brown
Keyword(s):  
High Mobility ◽  
High Mobility Group ◽  
Rabbit Brain ◽  
Hmg Proteins
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