Partial displacement of histone H1 from chromatin is required before it can be phosphorylated by mitotic H1 kinase in vitro.

In Tetrahymena cells, phosphorylation of linker histone H1 regulates transcription of specific genes. Phosphorylation acts by creating a localized negative charge patch and phenocopies the loss of H1 from chromatin, suggesting that it affects transcription by regulating the dissociation of H1 from chromatin. To test this hypothesis, we used FRAP of GFP-tagged H1 to analyze the effects of mutations that either eliminate or mimic phosphorylation on the binding of H1 to chromatin both in vivo and in vitro. We demonstrate that phosphorylation can increase the rate of dissociation of H1 from chromatin, providing a mechanism by which it can affect H1 function in vivo. We also demonstrate a previously undescribed ATP-dependent process that has a global effect on the dynamic binding of linker histone to chromatin.

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Roscovitine, a specific inhibitor of cyclin-dependent protein kinases, reversibly inhibits chromatin condensation during in vitro maturation of porcine oocytes

Zygote ◽

10.1017/s0967199401001356 ◽

2001 ◽

Vol 9 (4) ◽

pp. 309-316 ◽

Cited By ~ 21

Author(s):

Carsten Krischek ◽

Burkhard Meinecke

Keyword(s):

Map Kinase ◽

Protein Kinases ◽

Chromatin Condensation ◽

Specific Inhibitor ◽

Histone H1 ◽

Dependent Manner ◽

Free Medium ◽

Concentration Dependent Manner ◽

Dependent Protein

In the present study the effects of roscovitine on the in vitro nuclear maturation of porcine oocytes were investigated. Roscovitine, a specific inhibitor of cyclin-dependent protein kinases, prevented chromatin condensation in a concentration-dependent manner. This inhibition was reversible and was accompanied by non-activation of p34cdc2/histone H1 kinase. It also decreased enzyme activity of MAP kinase, suggesting a correlation between histone H1 kinase activation and the onset of chromatin condensation. The addition of roscovitine (50 μM) to extracts of metaphase II oocytes revealed that the MAP kinase activity was not directly affected by roscovitine, which indicates a possible link between histone H1 and MAP kinase. Chromatin condensation occurred between 20 and 28 h of culture of cumulus-oocyte complexes (COCs) in inhibitor-free medium (germinal vesicle stage I, GV1: 74.6% and 13.7%, respectively). Nearly the same proportion of chromatin condensation was detected in COCs incubated initially in inhibitor-free medium for 20-28 h and subsequently in roscovitine-supplemented medium (50 μM) for a further 2-10 h (GV I: 76.2% and 18.8%, respectively). This observation indicates that roscovitine prevents chromatin condensation even after an initial inhibitor-free cultivation for 20 h. Extending this initial incubation period to ≥22 h led to an activation of histone H1 and MAP kinase and increasing proportions of oocytes exhibiting chromatin condensation in the presence of roscovitine. It is concluded that histone H1 kinase is involved in the induction of chromatin condensation during in vitro maturation of porcine oocytes.

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

Biochemical Journal ◽

10.1042/bj1830657 ◽

1979 ◽

Vol 183 (3) ◽

pp. 657-662 ◽

Cited By ~ 24

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.

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Mitotic arrest caused by the amino terminus of Xenopus cyclin B2

Molecular and Cellular Biology ◽

10.1128/mcb.13.3.1480-1488.1993 ◽

1993 ◽

Vol 13 (3) ◽

pp. 1480-1488

Author(s):

H M van der Velden ◽

M J Lohka

Keyword(s):

Sea Urchin ◽

Kinase Activity ◽

Histone H1 ◽

Amino Terminus ◽

Protein Kinase Activity ◽

Truncated Protein ◽

Amino Terminal ◽

Egg Extracts ◽

The Stability

Progression through mitosis requires the inactivation of the protein kinase activity of the p34cdc2-cyclin complex by a mechanism involving the degradation of cyclin. We have examined the stability in Xenopus egg extracts of radiolabeled Xenopus or sea urchin B-type cyclins synthesized in reticulocyte lysates. Xenopus cyclin B2 and sea urchin cyclin B were stable in metaphase extracts from unfertilized eggs but were specifically degraded following addition of Ca2+ to the extracts. The degradation of either cyclin was inhibited by the addition of an excess of unlabeled Xenopus cyclin B2 but not by the addition of a number of control proteins. A truncated protein containing only the amino terminus of Xenopus cyclin B2, including sequences known to be essential for cyclin degradation in other species, also inhibited cyclin degradation, even though the truncated protein was stable in extracts following Ca2+ addition. The addition of the truncated protein did not stimulate histone H1 kinase activity in extracts but prevented the loss of H1 kinase activity that normally follows Ca2+ addition to metaphase extracts. When the amino-terminal fragment was added to extracts capable of several cell cycles in vitro, progression through the first mitosis was inhibited and elevated histone H1 kinase activity was maintained. These results indicate that although the amino terminus of cyclin does not contain all of the information necessary for cyclin destruction, it is capable of interacting with components of the cyclin destruction pathway and thereby preventing the degradation of full-length cyclins.

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Functions of Cyclin A1 in the Cell Cycle and Its Interactions with Transcription Factor E2F-1 and the Rb Family of Proteins

Molecular and Cellular Biology ◽

10.1128/mcb.19.3.2400 ◽

1999 ◽

Vol 19 (3) ◽

pp. 2400-2407 ◽

Cited By ~ 94

Author(s):

Rong Yang ◽

Carsten Müller ◽

Vong Huynh ◽

Yuen K. Fung ◽

Amy S. Yee ◽

...

Keyword(s):

Cell Cycle ◽

Transcription Factor ◽

Mitotic Cell ◽

Histone H1 ◽

Mitotic Cell Cycle ◽

Osteosarcoma Cell ◽

Cell Cycle Regulators ◽

Cyclin A1 ◽

Transcription Factor E2f

ABSTRACT Human cyclin A1, a newly discovered cyclin, is expressed in testis and is thought to function in the meiotic cell cycle. Here, we show that the expression of human cyclin A1 and cyclin A1-associated kinase activities was regulated during the mitotic cell cycle. In the osteosarcoma cell line MG63, cyclin A1 mRNA and protein were present at very low levels in cells at the G0 phase. They increased during the progression of the cell cycle and reached the highest levels in the S and G2/M phases. Furthermore, the cyclin A1-associated histone H1 kinase activity peaked at the G2/M phase. We report that cyclin A1 could bind to important cell cycle regulators: the Rb family of proteins, the transcription factor E2F-1, and the p21 family of proteins. The in vitro interaction of cyclin A1 with E2F-1 was greatly enhanced when cyclin A1 was complexed with CDK2. Associations of cyclin A1 with Rb and E2F-1 were observed in vivo in several cell lines. When cyclin A1 was coexpressed with CDK2 in sf9 insect cells, the CDK2-cyclin A1 complex had kinase activities for histone H1, E2F-1, and the Rb family of proteins. Our results suggest that the Rb family of proteins and E2F-1 may be important targets for phosphorylation by the cyclin A1-associated kinase. Cyclin A1 may function in the mitotic cell cycle in certain cells.

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Integrase-Specific Enhancement and Suppression of Retroviral DNA Integration by Compacted Chromatin Structure In Vitro

Journal of Virology ◽

10.1128/jvi.78.11.5848-5855.2004 ◽

2004 ◽

Vol 78 (11) ◽

pp. 5848-5855 ◽

Cited By ~ 39

Author(s):

Konstantin D. Taganov ◽

Isabel Cuesta ◽

René Daniel ◽

Lisa Ann Cirillo ◽

Richard A. Katz ◽

...

Keyword(s):

Transcription Factors ◽

Chromatin Structure ◽

Site Selection ◽

Integration Site ◽

Histone H1 ◽

Detectable Effect ◽

Host Chromosome ◽

Dna Integration ◽

Hiv 1

ABSTRACT Integration of viral DNA into the host chromosome is an obligatory step in retroviral replication and is dependent on the activity of the viral enzyme integrase. To examine the influence of chromatin structure on retroviral DNA integration in vitro, we used a model target comprising a 13-nucleosome extended array that includes binding sites for specific transcription factors and can be compacted into a higher-ordered structure. We found that the efficiency of in vitro integration catalyzed by human immunodeficiency virus type 1 (HIV-1) integrase was decreased after compaction of this target with histone H1. In contrast, integration by avian sarcoma virus (ASV) integrase was more efficient after compaction by either histone H1 or a high salt concentration, suggesting that the compacted structure enhances this reaction. Furthermore, although site-specific binding of transcription factors HNF3 and GATA4 blocked ASV DNA integration in extended nucleosome arrays, local opening of H1-compacted chromatin by HNF3 had no detectable effect on integration, underscoring the preference of ASV for compacted chromatin. Our results indicate that chromatin structure affects integration site selection of the HIV-1 and ASV integrases in opposite ways. These distinct properties of integrases may also affect target site selection in vivo, resulting in an important bias against or in favor of integration into actively transcribed host DNA.

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Nucleosome cores assembled in vitro occupy two preferred frames flanking the histone H1 gene from Psammechinus miliaris

Biochemistry ◽

10.1021/bi00388a039 ◽

1987 ◽

Vol 26 (14) ◽

pp. 4449-4453 ◽

Cited By ~ 1

Author(s):

Jacques D. Retief ◽

B. Trevor Sewell ◽

Claus Von Holt

Keyword(s):

Histone H1 ◽

Psammechinus Miliaris

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Histone carbonylation in vivo and in vitro

Biochemical Journal ◽

10.1042/bj3510769 ◽

2000 ◽

Vol 351 (3) ◽

pp. 769-777 ◽

Cited By ~ 38

Author(s):

Georg T. WONDRAK ◽

Daniel CERVANTES-LAUREAN ◽

Elaine L. JACOBSON ◽

Myron K. JACOBSON

Keyword(s):

Histone H1 ◽

Nuclear Proteins ◽

Carbonyl Groups ◽

Cell Nuclei ◽

Strand Breaks ◽

Core Histones ◽

Dna Strand ◽

And Function

Non-enzymic damage to nuclear proteins has potentially severe consequences for the maintenance of genomic integrity. Introduction of carbonyl groups into histones in vivo and in vitro was assessed by Western blot immunoassay and reductive incorporation of tritium from radiolabelled NaBH4 (sodium borohydride). Histone H1 extracted from bovine thymus, liver and spleen was found to contain significantly elevated amounts of protein-bound carbonyl groups as compared with core histones. The carbonyl content of nuclear proteins of rat pheochromocytoma cells (PC12 cells) was not greatly increased following oxidative stress induced by H2O2, but was significantly increased following alkylating stress induced by N-methyl-N´-nitro-N-nitrosoguanidine or by combined oxidative and alkylating stress. Free ADP-ribose, a reducing sugar generated in the nucleus in proportion to DNA strand breaks, was shown to be a potent histone H1 carbonylating agent in isolated PC12 cell nuclei. Studies of the mechanism of histone H1 modification by ADP-ribose indicate that carbonylation involves formation of a stable acyclic ketoamine. Our results demonstrate preferential histone H1 carbonylation in vivo, with potentially important consequences for chromatin structure and function.

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Extracellular matrix histone H1 binds to perlecan, is present in regenerating skeletal muscle and stimulates myoblast proliferation

Journal of Cell Science ◽

10.1242/jcs.115.10.2041 ◽

2002 ◽

Vol 115 (10) ◽

pp. 2041-2051 ◽

Cited By ~ 2

Author(s):

Juan Pablo Henriquez ◽

Juan Carlos Casar ◽

Luis Fuentealba ◽

David J. Carey ◽

Enrique Brandan

Keyword(s):

Skeletal Muscle ◽

Extracellular Matrix ◽

Heparan Sulfate ◽

Muscle Differentiation ◽

Histone H1 ◽

Heparan Sulfate Proteoglycans ◽

Skeletal Muscle Regeneration ◽

Proliferative Effect ◽

Myoblast Proliferation

Heparan sulfate chains of proteoglycans bind to and regulate the function of a wide variety of ligands. In myoblasts, heparan sulfate proteoglycans modulate basic fibroblast growth factor activity and regulate skeletal muscle differentiation. The aim of this study was to identify endogenous extracellular ligands for muscle cell heparan sulfate proteoglycans.[35S]heparin ligand blot assays identified a 33/30 kDa doublet(p33/30) in detergent/high ionic strength extracts and heparin soluble fractions obtained from intact C2C12 myoblasts. p33/30 is localized on the plasma membrane or in the extracellular matrix where its level increases during muscle differentiation. Heparin-agarose-purified p33/30 was identified as histone H1. In vitro binding assays showed that histone H1 binds specifically to perlecan. Immunofluorescence microscopy showed that an extracellular pool of histone H1 colocalizes with perlecan in the extracellular matrix of myotube cultures and in regenerating skeletal muscle. Furthermore, histone H1 incorporated into the extracellular matrix strongly stimulated myoblast proliferation via a heparan-sulfate-dependent mechanism.These results indicate that histone H1 is present in the extracellular matrix of skeletal muscle cells, where it interacts specifically with perlecan and exerts a strong proliferative effect on myoblasts, suggesting a role for histone H1 during skeletal muscle regeneration.

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Characterization of monomeric DNA-binding protein Histone H1 inLeishmania braziliensis

Parasitology ◽

10.1017/s0031182011000898 ◽

2011 ◽

Vol 138 (9) ◽

pp. 1093-1101 ◽

Cited By ~ 2

Author(s):

EMMA CARMELO ◽

GLORIA GONZÁLEZ ◽

TERESA CRUZ ◽

ANTONIO OSUNA ◽

MARIANO HERNÁNDEZ ◽

...

Keyword(s):

Mass Spectrometry ◽

Dna Binding ◽

Chromatin Condensation ◽

Histone H1 ◽

Mass Spectrometry Analysis ◽

Globular Domain ◽

Mobility Shift ◽

Aggregation State ◽

Genome Database

SUMMARYHistone H1 inLeishmaniapresents relevant differences compared to higher eukaryote counterparts, such as the lack of a DNA-binding central globular domain. Despite that, it is apparently fully functional since its differential expression levels have been related to changes in chromatin condensation and infectivity, among other features. The localization and the aggregation state ofL. braziliensisH1 has been determined by immunolocalization, mass spectrometry, cross-linking and electrophoretic mobility shift assays. Analysis of H1 sequences from theLeishmaniaGenome Database revealed that our protein is included in a very divergent group of histones H1 that is present only inL. braziliensis.An antibody raised against recombinantL. braziliensisH1 recognized specifically that protein by immunoblot inL. braziliensisextracts, but not in otherLeishmaniaspecies, a consequence of the sequence divergences observed amongLeishmaniaspecies. Mass spectrometry analysis andin vitroDNA-binding experiments have also proven thatL. braziliensisH1 is monomeric in solution, but oligomerizes upon binding to DNA. Finally, despite the lack of a globular domain,L. braziliensisH1 is able to form complexes with DNAin vitro, with higher affinity for supercoiled compared to linear DNA.

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