Abstract:
:The mechanisms which cause macromolecules to form discrete compartments within the nucleus are not understood. Here, two ubiquitous compartments, nucleoli, and PML bodies, are shown to disassemble when K562 cell nuclei expand in medium of low monovalent cation concentration; their major proteins dispersed as seen by immunofluorescence and immunoelectron microscopy, and nucleolar transcript elongation fell by approximately 85%. These compartments reassembled and nucleolar transcription recovered in the same medium after adding inert, penetrating macromolecules (8 kDa polyethylene glycol (PEG), or 10.5 kDa dextran) to 12% w/v, showing that disassembly was not caused by the low cation concentration. These responses satisfy the criteria for crowding or volume exclusion effects which occur in concentrated mixtures of macromolecules; upon expansion the macromolecular concentration within the nucleus falls, and can be restored by PEG or dextran. These observations, together with evidence of a high concentration of macromolecules in the nucleus (in the range of 100mg/ml) which must cause strong crowding forces, suggest strongly that these forces play an essential role in driving the formation, and maintaining the function of nuclear compartments. This view is consistent with their dynamic and mobile nature and can provide interpretations of several unexplained observations in nuclear biology.
journal_name
J Struct Bioljournal_title
Journal of structural biologyauthors
Hancock Rdoi
10.1016/j.jsb.2003.12.008keywords:
subject
Has Abstractpub_date
2004-06-01 00:00:00pages
281-90issue
3eissn
1047-8477issn
1095-8657pii
S1047847703003216journal_volume
146pub_type
杂志文章abstract::The baculum is an extraskeletal bone located in the penis of a few species in several orders of mammals such as carnivores, insectivores, rodents, bats and primates. This study aims to describe the structure, architecture and mechanical properties of the canine baculum. To this end canine bacula from castrated and unc...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1016/j.jsb.2011.06.006
更新日期:2011-09-01 00:00:00
abstract::Human coagulation factor VIIai that lacks the Gla domain (residues 1-44) has been prepared, purified, and crystallised. First, recombinant factor VII was activated to form factor VIIa, the active site was then inhibited with 1,5-dansyl-Glu-Gly-Arg-chloromethyl ketone, and finally the Gla domain was removed by chymotry...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1006/jsbi.1998.4078
更新日期:1999-03-01 00:00:00
abstract::Null-mutation in Drosophila importin-alpha2, such as the deficiency imp-alpha2(D14), causes recessive female sterility with the formation of dumpless eggs. In imp-alpha2(D14) the transfer of nurse cell components to the oocyte is interrupted and the Kelch protein, an oligomeric ring canal actin organizer, is normally ...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1016/j.jsb.2005.12.007
更新日期:2006-04-01 00:00:00
abstract::We have cloned and expressed in Escherichia coli cDNA for rat nuclear transport factor 2 (NTF2), a key cytoplasmic factor that facilitates the import of proteins into the nucleus through nuclear pores. We have used this bacterially expressed material to produce orthorhombic crystals suitable for high-resolution X-ray ...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1006/jsbi.1996.0049
更新日期:1996-03-01 00:00:00
abstract::The recent high-resolution structure of the toxin FraC derived from the sea anemone Actinia fragacea has provided new insight into the mechanism of pore formation by actinoporins. In this work, we report two new crystal forms of FraC in its oligomeric prepore conformation. Together with the previously reported structu...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1016/j.jsb.2012.06.003
更新日期:2012-11-01 00:00:00
abstract::The ability of bacteria to combat oxidative stress is imperative for their survival. The Alkyl hydroperoxide Reductase (AhpR) system, composed of the AhpC and AhpF proteins, is one of the dominant antioxidant defense systems required for scavenging hydrogen peroxide and organic peroxide. Therefore, it is necessary to ...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1016/j.jsb.2015.11.004
更新日期:2016-01-01 00:00:00
abstract::In many microorganisms, menaquinone is an essential lipid-soluble electron carrier. Recently, an alternative menaquinone biosynthetic pathway was found in some microorganisms [Hiratsuka, T., Furihata, K., Ishikawa, J., Yamashita, H., Itoh, N., Seto, H., Dairi, T., 2008. An alternative menaquinone biosynthetic pathway ...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1016/j.jsb.2009.07.007
更新日期:2009-12-01 00:00:00
abstract::F-plasmid-mediated bacterial conjugation was studied with hfr (traDts) and tra I mutant Escherichia coli donor strains. This allowed us to observe a statistically significant number of conjugation-specific contacts by video and electron microscopy. Single mating events between E. coli were observed in real time by vid...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1016/1047-8477(91)90018-r
更新日期:1991-10-01 00:00:00
abstract::A new method for the flexible fitting of high-resolution structures into low-resolution maps of macromolecular complexes from electron microscopy has been recently described in applications to simulated electron density maps. This method uses a linear combination of low-frequency normal modes in an iterative manner to...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1016/j.jsb.2004.03.002
更新日期:2004-09-01 00:00:00
abstract::Hitherto, the packing arrangement of the aquaporin-1 (AQP1) tetramer in 2-dimensional (2-D) crystals (two-sided plane group p42(1)2) was observed to be largely similar (canonical crystal form) despite the difference in the source of the protein, the glycosylation state of the protein, the type of lipids, and the ratio...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1006/jsbi.2000.4211
更新日期:2000-05-01 00:00:00
abstract::Chemotactic methyltransferase, CheR catalyse methylation of specific glutamate residues in the cytoplasmic domain of methyl-accepting chemotactic protein receptors (MCPRs). The methylation of MCPRs is essential for the chemical sensing and chemotactic bacterial mobility towards favorable chemicals or away from unfavor...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1016/j.jsb.2016.08.005
更新日期:2016-12-01 00:00:00
abstract::Neuraminidase (NA) inhibitors can suppress NA activity to block the release of progeny virions and are effective against influenza viruses. As potential anti-flu drugs with unique functions, NA inhibitors are greatly concerned by the worldwide scientists. It has been reported recently that one of the novel quindoline ...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1016/j.jsb.2017.12.014
更新日期:2018-05-01 00:00:00
abstract::Three-dimensional crystals were obtained for the membrane domain of the human erythrocyte anion exchanger (AE1, Band 3). Protein homogeneity and stability and the delicate balance between the detergent used and the amount of phospholipids copurifying are critical to the formation of three-dimensional crystals of the A...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1016/s1047-8477(02)00010-2
更新日期:2002-03-01 00:00:00
abstract::Using a 400-kV cryoelectron microscope, we have obtained tomographic reconstructions of frozen-hydrated sea urchin axonemes with 8-10-nm resolution, as assessed by detection of characteristic components including doublet microtubules, radial spokes, central sheath projections, and outer dynein arms. We did not detect ...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1016/s1047-8477(02)00020-5
更新日期:2002-04-01 00:00:00
abstract::For the understanding of mineral formation processes from solution it is important to obtain a deeper insight into the dynamics of crystal growth. In this study we applied for this purpose a novel atmospheric scanning electron microscope that allows the investigation of CaCO3 particle formation in solution under atmos...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1016/j.jsb.2013.05.017
更新日期:2013-08-01 00:00:00
abstract::An evaluation system and a web infrastructure were developed for the second cryo-EM model challenge. The evaluation system includes tools to validate stereo-chemical plausibility of submitted models, check their fit to the corresponding density maps, estimate their overall and per-residue accuracy, and assess their si...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1016/j.jsb.2018.07.006
更新日期:2018-10-01 00:00:00
abstract::Early electron microscope studies of developing wool and hair established that trichocyte (hard alpha-) keratin fibers have a composite structure in which filaments, subsequently shown to belong to the class of intermediate filaments (IF), were embedded in a matrix of sulfur-rich proteins. These studies also showed th...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1016/s1047-8477(03)00027-3
更新日期:2003-05-01 00:00:00
abstract::Cryogenic electron microscopy (cryo-EM) and single-particle analysis enables determination of near-atomic resolution structures of biological molecules. However, large computational requirements limit throughput and rapid testing of new image processing tools. We developed PRIME, an algorithm part of the SIMPLE softwa...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1016/j.jsb.2018.08.005
更新日期:2018-11-01 00:00:00
abstract::Tricorn protease from Thermoplasma acidophilum is a hexameric enzyme; in vivo the hexamers assemble further to form large icosahedral capsids of 14.6 MDa. Recombinant Tricorn protease was purified as an enzymatically active hexamer of 0.72 MDa that formed crystals of octahedral morphology under low-ionic-strength cond...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1006/jsbi.2001.4360
更新日期:2001-04-01 00:00:00
abstract::A defining property of a crystal is its symmetry. This mini-review sets out to summarize all aspects that define 2D crystallographic symmetry as applied to the study of macromolecular structure. It begins by defining molecular point symmetries, before covering crystallographic symmetry operations in 2D, common notatio...
journal_title:Journal of structural biology
pub_type: 杂志文章,评审
doi:10.1016/j.jsb.2007.07.002
更新日期:2007-12-01 00:00:00
abstract::Processing of nuclear pre-mRNA is an important step in the regulation of gene expression and involves 5(')- and 3(')-end processing, splicing, and editing. Mammalian nuclear pre-mRNAs are assembled in large ribonucleoprotein (lnRNP) complexes, in which the entire population of nuclear pre-mRNA is individually packaged...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1016/s1047-8477(02)00541-5
更新日期:2002-10-01 00:00:00
abstract::Titin is a giant elastic protein responsible for passive force generated by the stretched striated-muscle sarcomere. Passive force develops in titin's extensible region which consists of the PEVK segment in series with tandemly arranged immunoglobulin (Ig)-like domains. Here we studied the mechanics of tandem Ig segme...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1006/jsbi.2002.4458
更新日期:2002-01-01 00:00:00
abstract::Yersinia enterocolitica is a pectinolytic zoonotic foodborne pathogen, the genome of which contains pectin-binding proteins and several different classes of pectinases, including polysaccharide lyases (PLs) and an exopolygalacturonase. These proteins operate within a coordinated pathway to completely saccharify homoga...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1016/j.jsb.2019.06.003
更新日期:2019-09-01 00:00:00
abstract::The Contrast Transfer Function (CTF) of an image, which modulates images taken from a Transmission Electron Microscope (TEM), is usually determined from the radial average of the power spectrum of the image (Frank, J., Three-dimensional Electron Microscopy of Macromolecular Assemblies, Oxford University Press, Oxford,...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1016/j.jsb.2008.06.012
更新日期:2008-10-01 00:00:00
abstract::This study demonstrates the effects of progesterone on eggshell quality and ultrastructure by injecting progesterone into laying hens 2 and 5 h post-oviposition, respectively. Progesterone injected 2 h post-oviposition (P4-2 h) improved eggshell quality with a significant decrease (P < 0.01) in the thickness of the ma...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1016/j.jsb.2019.107430
更新日期:2020-02-01 00:00:00
abstract::Two mechanisms have thus far been characterized for the assistance by chaperonins of the folding of other proteins. The first and best described is that of the prokaryotic chaperonin GroEL, which interacts with a large spectrum of proteins. GroEL uses a nonspecific mechanism by which any conformation of practically an...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1006/jsbi.2001.4359
更新日期:2001-08-01 00:00:00
abstract::Titin is a giant protein that spans half of the striated muscle sarcomere. The I-band portion of titin extends as the sarcomere is stretched, developing what is known as passive force. This portion of the molecule is composed mainly of tandem immunoglobulin (Ig) segments, consisting of serially linked Ig-like domains,...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1006/jsbi.1998.3984
更新日期:1998-01-01 00:00:00
abstract::The biomechanical properties of the zone of calcified cartilage (ZCC) in articulating joints are of clinical relevance due to the role ZCC plays in load transfer from cartilage to bone. To determine the micron-level mechanical properties and their correlation to mineral concentration in the ZCC, we combined nanoindent...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1016/j.jsb.2004.10.010
更新日期:2005-02-01 00:00:00
abstract::The question as to whether keratin intermediate filaments (KIF) are built from a unique "building block" consisting of a pair of coiled-coil molecules has been studied by examining the earliest stages of reassembly of mouse K1/K10 KIF in vitro. Particles formed in protein solutions of about 45 micrograms/ml (near or b...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1016/1047-8477(91)90020-w
更新日期:1991-10-01 00:00:00
abstract::Thebaine 6-O-demethylase (T6ODM) from Papaver somniferum (opium poppy), which belongs to the non-heme 2-oxoglutarate/Fe(II)-dependent dioxygenases (ODD) family, is a key enzyme in the morphine biosynthesis pathway. Initially, T6ODM was characterized as an enzyme catalyzing O-demethylation of thebaine to neopinone and ...
journal_title:Journal of structural biology
pub_type: 杂志文章
doi:10.1016/j.jsb.2018.01.007
更新日期:2018-06-01 00:00:00