scholarly journals Possible Role of Histone H1 in the Regulation of Furin-dependent Proprotein Processing

2007 ◽  
Vol 39 (3) ◽  
pp. 173-180
Author(s):  
Jinbo HAN ◽  
Jianxin GU ◽  
Chengwu CHI
Keyword(s):  
Histone H1 ◽  
Proprotein Processing

scholarly journals Role of the histone “tails” in the folding of oligonucleosomes depleted of histone H1.

1992 ◽  
Vol 267 (27) ◽  
pp. 19587-19595 ◽  
Author(s):  
M Garcia-Ramirez ◽  
F Dong ◽  
J Ausio
Keyword(s):  
Histone H1 ◽  
Histone Tails

scholarly journals Site-specific ubiquitylation acts as a regulator of linker histone H1

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Eva Höllmüller ◽  
Simon Geigges ◽  
Marie L. Niedermeier ◽  
Kai-Michael Kammer ◽  
Simon M. Kienle ◽  
...  
Keyword(s):  
Posttranslational Modifications ◽  
Histone H1 ◽  
Linker Histone ◽  
Active Chromatin ◽  
Site Specific ◽  
Linker Histone H1 ◽  
Fundamental Process ◽  
Core Histones ◽  
Wide Scale

AbstractDecoding the role of histone posttranslational modifications (PTMs) is key to understand the fundamental process of epigenetic regulation. This is well studied for PTMs of core histones but not for linker histone H1 in general and its ubiquitylation in particular due to a lack of proper tools. Here, we report on the chemical synthesis of site-specifically mono-ubiquitylated H1.2 and identify its ubiquitin-dependent interactome on a proteome-wide scale. We show that site-specific ubiquitylation of H1 at position K64 modulates interactions with deubiquitylating enzymes and the deacetylase SIRT1. Moreover, it affects H1-dependent chromatosome assembly and phase separation resulting in a more open chromatosome conformation generally associated with a transcriptionally active chromatin state. In summary, we propose that site-specific ubiquitylation plays a general regulatory role for linker histone H1.

scholarly journals Possible role of histone acetylation and histone H1° replacement for the initiation of replication in regenerating rat liver

1991 ◽  
Vol 280 (3) ◽  
pp. 777-781
Author(s):  
G Weiss ◽  
H Talasz ◽  
B Puschendorf
Keyword(s):  
Dna Synthesis ◽  
Histone Acetylation ◽  
Rat Liver ◽  
Histone Acetyltransferase ◽  
Histone H1 ◽  
Acetyltransferase Activity ◽  
Initiation Of Replication ◽  
Histone Acetyltransferase Activity

The role of histone acetylation and DNA synthesis has been investigated extensively in the regenerating rat liver system in the presence and absence of the cyclophosphamide derivative mafosfamide. We demonstrate a mafosfamide-induced inhibition of maximum histone acetyltransferase activity followed by a second elevation of enzyme activity and an accompanying total suppression of DNA synthesis for 7-8 h. The maximum of histone acetyltransferase activity, in parallel with an elevated acetylation in vivo, the consecutive replacement of histone H1(0) amd initiation of replication occur sequentially in the presence and absence of mafosfamide, but with a temporary delay of 7-8 h. Our data indicate that modifications of histone acetyltransferase (EC 2.3.1.48) activity do not significantly influence the acetylation patterns of histones H3 and H4. The mafosfamide-induced change of histone acetyltransferase activity and acetylation in vivo, the shift of histone H1(0) exchange and the consecutive transition of initiation of replication suggest that these three events might be functionally related.

scholarly journals Histone H1 is essential for mitotic chromosome architecture and segregation in Xenopus laevis egg extracts

2005 ◽  
Vol 169 (6) ◽  
pp. 859-869 ◽  
Author(s):  
Thomas J. Maresca ◽  
Benjamin S. Freedman ◽  
Rebecca Heald
Keyword(s):  
Xenopus Laevis ◽  
Metaphase Plate ◽  
Histone H1 ◽  
Linker Histone ◽  
Chromosome Architecture ◽  
Linker Histone H1 ◽  
Egg Extracts ◽  
Chromatin Proteins ◽  
And Function

During cell division, condensation and resolution of chromosome arms and the assembly of a functional kinetochore at the centromere of each sister chromatid are essential steps for accurate segregation of the genome by the mitotic spindle, yet the contribution of individual chromatin proteins to these processes is poorly understood. We have investigated the role of embryonic linker histone H1 during mitosis in Xenopus laevis egg extracts. Immunodepletion of histone H1 caused the assembly of aberrant elongated chromosomes that extended off the metaphase plate and outside the perimeter of the spindle. Although functional kinetochores assembled, aligned, and exhibited poleward movement, long and tangled chromosome arms could not be segregated in anaphase. Histone H1 depletion did not significantly affect the recruitment of known structural or functional chromosomal components such as condensins or chromokinesins, suggesting that the loss of H1 affects chromosome architecture directly. Thus, our results indicate that linker histone H1 plays an important role in the structure and function of vertebrate chromosomes in mitosis.

Potential Role of a Novel Transcriptional Coactivator PELP1 in Histone H1 Displacement in Cancer Cells

2004 ◽  
Vol 64 (18) ◽  
pp. 6416-6423 ◽  
Author(s):  
Sujit S. Nair ◽  
Sandip K. Mishra ◽  
Zhibo Yang ◽  
Seetharaman Balasenthil ◽  
Rakesh Kumar ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Potential Role ◽  
Histone H1 ◽  
Transcriptional Coactivator

A compendium of the histone H1 family of somatic subtypes: An elusive cast of characters and their characteristics

2001 ◽  
Vol 79 (3) ◽  
pp. 289-304 ◽  
Author(s):  
Missag H Parseghian ◽  
Barbara A Hamkalo
Keyword(s):  
Historical Context ◽  
Histone H1 ◽  
General Function ◽  
Linker Histones ◽  
Chromatin Compaction ◽  
The Core ◽  
The Past ◽  
Current State ◽  
Core Histones

The last 35 years has seen a substantial amount of information collected about the somatic H1 subtypes, yet much of this work has been overshadowed by research into highly divergent isoforms of H1, such as H5. Reports from several laboratories in the past few years have begun to call into question some of the traditional views regarding the general function of linker histones and their heterogeneity. Hence, the impression in some circles is that less is known about these ubiquitous nuclear proteins as compared with the core histones. The goal of the following review is to acquaint the reader with the ubiquitous somatic H1s by categorizing them and their characteristics into several classes. The reasons for our current state of misunderstanding is put into a historical context along with recent controversies centering on the role of H1 in the nucleus. Finally, we propose a model that may explain the functional role of H1 heterogeneity in chromatin compaction.Key words: histone H1, linker histones, chromatin organization, chromatin compaction, heat shock.

scholarly journals Role of Endoproteolytic Dibasic Proprotein Processing in Maturation of Secretory Proteins inTrichoderma reesei

1998 ◽  
Vol 64 (9) ◽  
pp. 3202-3208 ◽  
Author(s):  
Sabine P. Goller ◽  
Doris Schoisswohl ◽  
Michel Baron ◽  
Martine Parriche ◽  
Christian P. Kubicek
Keyword(s):  
Secretory Proteins ◽  
Heterologous Proteins ◽  
Homologous Proteins ◽  
Cell Extracts ◽  
Endopeptidase Activity ◽  
Proprotein Processing ◽  
Target Sequences

ABSTRACT Cell extracts of Trichoderma reesei exhibited dibasic endopeptidase activity toward the carboxylic side of KR, RR, and PR sequences. This activity was stimulated by the presence of Ca2+ ions and localized in vesicles of low bouyant density; it therefore exhibited some similarity to yeast Kex2. Analytical chromatofocusing revealed a single peak of activity. The dibasic endopeptidase activity was strongly and irreversibly inhibited in vitro as well as in vivo by 1 mM p-amidinophenylmethylsulfonyl fluoride (pAPMSF) but not by PMSF at concentrations up to 5 mM. We therefore used pAPMSF to study the role of the dibasic endopeptidase in the secretion of protein by T. reesei. Secretion of xylanase I (proprotein processing sequence -R-R-↓-R-↓-A-) and xylanase II (-K-R-↓-Q-) was strongly inhibited by 1 mM pAPMSF, and a larger, unprocessed enzyme form was detected intracellularly under these conditions. Secretion of cellobiohydrolase II (CBH II; -E-R-↓-Q-) was only slightly inhibited by pAPMSF, and no accumulation of unprocessed precursors was detected. In contrast, secretion of CBH I (-R-A-↓-Q-) was stimulated by pAPMSF addition, and a simultaneous decrease in the concentration of intracellular CBH I was detected. Similar experiments were also carried out with a single heterologous protein, ShBLE, the phleomycin-binding protein fromStreptoalloteichus hindustanus, fused to a series of model proprotein-processing sequences downstream of the expression signals of the Aspergillus nidulans gpdA promoter. Consistent with the results obtained with homologous proteins, pAPMSF inhibited the secretion of ShBLE with fusions containing dibasic (RK and KR) target sequences, but it even stimulated secretion in fusions to LR, NHA, and EHA target sequences. Addition of 5 mM PMSF, a nonspecific inhibitor of serine protease, nonspecifically inhibited the secretion of heterologous proteins from fusions bearing the NHA and LR targets. These data point to the existence of different endoproteolytic proprotein processing enzymes in T. reesei and demonstrate that dibasic processing is obligatory for the secretion of the proproteins containing this target.

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