Immunochemical approaches to the study of histone H1 and high mobility group chromatin proteins

1990 ◽  
Vol 92 (1) ◽  
Author(s):  
JordankaS. Zlatanova
Keyword(s):  
High Mobility ◽  
Histone H1 ◽  
High Mobility Group ◽  
Chromatin Proteins

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 The High Mobility Group A1 (HMGA1) Chromatin Architectural Factor Modulates Nuclear Stiffness in Breast Cancer Cells

2019 ◽  
Vol 20 (11) ◽  
pp. 2733 ◽  
Author(s):  
Beatrice Senigagliesi ◽  
Carlotta Penzo ◽  
Luisa Ulloa Severino ◽  
Riccardo Maraspini ◽  
Sara Petrosino ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Protein A ◽  
High Mobility ◽  
Histone H1 ◽  
High Mobility Group ◽  
Expression Level ◽  
Essential Condition ◽  
Cellular Models ◽  
Hmga1 Expression

Plasticity is an essential condition for cancer cells to invade surrounding tissues. The nucleus is the most rigid cellular organelle and it undergoes substantial deformations to get through environmental constrictions. Nuclear stiffness mostly depends on the nuclear lamina and chromatin, which in turn might be affected by nuclear architectural proteins. Among these is the HMGA1 (High Mobility Group A1) protein, a factor that plays a causal role in neoplastic transformation and that is able to disentangle heterochromatic domains by H1 displacement. Here we made use of atomic force microscopy to analyze the stiffness of breast cancer cellular models in which we modulated HMGA1 expression to investigate its role in regulating nuclear plasticity. Since histone H1 is the main modulator of chromatin structure and HMGA1 is a well-established histone H1 competitor, we correlated HMGA1 expression and cellular stiffness with histone H1 expression level, post-translational modifications, and nuclear distribution. Our results showed that HMGA1 expression level correlates with nuclear stiffness, is associated to histone H1 phosphorylation status, and alters both histone H1 chromatin distribution and expression. These data suggest that HMGA1 might promote chromatin relaxation through a histone H1-mediated mechanism strongly impacting on the invasiveness of cancer cells.

scholarly journals High Mobility Group 1 Protein Is Not Stably Associated with the Chromosomes of Somatic Cells

1997 ◽  
Vol 137 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Luca Falciola ◽  
Fabio Spada ◽  
Sabina Calogero ◽  
Gernot Längst ◽  
Renate Voit ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Cultured Cells ◽  
High Mobility ◽  
Histone H1 ◽  
Biochemical Properties ◽  
High Mobility Group ◽  
Live Cells ◽  
Differentiated Cells ◽  
Group 1

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.

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 Structural organization of DNA–protein complexes of chromatin studied by vibrational and electronic circular dichroism

2010 ◽  
Vol 24 (3-4) ◽  
pp. 239-244 ◽  
Author(s):  
Alexander Polyanichko ◽  
Helmut Wieser
Keyword(s):  
Circular Dichroism ◽  
Protein Complexes ◽  
High Mobility ◽  
Histone H1 ◽  
Cd Spectroscopy ◽  
Linker Histone ◽  
High Mobility Group ◽  
Ir Absorption ◽  
Linker Histone H1 ◽  
Circular Dichroïsm

Structure and functioning of chromatin is determined by interactions of DNA with numerous nuclear proteins. The most abundant and yet not completely understood non-histone chromosomal proteins are those belonging to a High Mobility Group (HMG) namely HMGB1. The interplay of this protein on DNA with linker histone H1 and other proteins determines both structure and functioning of the chromatin. A combination of UV and IR absorption and circular dichroism (CD) spectroscopy was applied to investigate the structure and formation of large supramolecular DNA–protein complexes. This combination of techniques was used to overcome limitations of UV-CD (ECD) spectroscopy due to considerable light scattering in such solutions. Based on the analysis of FTIR and UV circular dichroism spectra and AFM imaging the interaction of DNA with high-mobility group non-histone chromatin protein HMGB1 and linker histone H1 was studied.

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