Radiation Threshold Damageability of Cells Depending on the Availability of the Cell Nucleus

2014 ◽  
Vol 881-883 ◽  
pp. 360-363
Author(s):  
V.V. Dyachkov ◽  
Y.A. Zaripova ◽  
N.G. Riger ◽  
A.L. Shakirov ◽  
A.V. Yushkov
Keyword(s):  
Cell Nucleus ◽  
Dose Effect ◽  
High Threshold ◽  
Alpha Radiation ◽  
Work Related ◽  
Threshold Phenomenon ◽  
Biophysical Processes ◽  
A Cell ◽  
Radioactive Radiation ◽  
Effects Of Radiation

The paper describes biophysical processes occurring in membranes under the influence of alpha-radiation of radon isotopes. The basic idea is to experimentally detect the effects of radiation damage to cells of the α-particle with energy of 5.5 MeV, and in particular, to determine the dependence threshold in a function of the "dose-effect" in the presence of DNA molecules into cells. Actuality of work related to the fact that up to now remains open the problem – is whether damageability of radioactive radiation threshold or without threshold phenomenon. It was found that the irradiation of biological models of cells - liposomes and spherosomes uniquely showed the lack threshold of damageability. Irradiation red blood cells not having a cell nucleus, occurs as a threshold phenomenon. Finally, the irradiation of the lactic acid bacteria occurs with a high threshold

G-protein-coupled receptors signalling at the cell nucleus: an emerging paradigmThis paper is one of a selection of papers published in this Special Issue, entitled The Nucleus: A Cell Within A Cell.

2006 ◽  
Vol 84 (3-4) ◽  
pp. 287-297 ◽  
Author(s):  
Fernand Gobeil ◽  
Audrey Fortier ◽  
Tang Zhu ◽  
Michela Bossolasco ◽  
Martin Leduc ◽  
...  
Keyword(s):  
G Protein ◽  
Cell Nucleus ◽  
Intracellular Signaling ◽  
Molecular Mechanisms ◽  
Nuclear Translocation ◽  
Cell Metabolism ◽  
Hormone Secretion ◽  
G Protein Coupled Receptors ◽  
A Cell ◽  
G Protein Coupled

G-protein-coupled receptors (GPCRs) comprise a wide family of monomeric heptahelical glycoproteins that recognize a broad array of extracellular mediators including cationic amines, lipids, peptides, proteins, and sensory agents. Thus far, much attention has been given towards the comprehension of intracellular signaling mechanisms activated by cell membrane GPCRs, which convert extracellular hormonal stimuli into acute, non-genomic (e.g., hormone secretion, muscle contraction, and cell metabolism) and delayed, genomic biological responses (e.g., cell division, proliferation, and apoptosis). However, with respect to the latter response, there is compelling evidence for a novel intracrine mode of genomic regulation by GPCRs that implies either the endocytosis and nuclear translocation of peripheral-liganded GPCR and (or) the activation of nuclearly located GPCR by endogenously produced, nonsecreted ligands. A noteworthy example of the last scenario is given by heptahelical receptors that are activated by bioactive lipoids (e.g., PGE2 and PAF), many of which may be formed from bilayer membranes including those of the nucleus. The experimental evidence for the nuclear localization and signalling of GPCRs will be reviewed. We will also discuss possible molecular mechanisms responsible for the atypical compartmentalization of GPCRs at the cell nucleus, along with their role in gene expression.

Some Electrical Properties of the Membrane of a Cell Nucleus

Nature ◽  
1962 ◽  
Vol 195 (4840) ◽  
pp. 462-464 ◽  
Author(s):  
WERNER R. LOEWENSTEIN ◽  
YOSHINOBU KANNO
Keyword(s):  
Electrical Properties ◽  
Cell Nucleus ◽  
A Cell

Nuclear import of spliceosomal snRNPsThis paper is one of a selection of papers published in this Special Issue, entitled The Nucleus: A Cell Within A Cell.

2006 ◽  
Vol 84 (3-4) ◽  
pp. 367-376 ◽  
Author(s):  
Christiane Rollenhagen ◽  
Nelly Panté
Keyword(s):  
Cell Nucleus ◽  
Nuclear Import ◽  
Current Knowledge ◽  
Protein Complexes ◽  
Special Issue ◽  
A Cell ◽  
Rna Maturation ◽  
Small Nuclear Ribonucleoproteins ◽  
Selection Of

Uridine-rich small nuclear ribonucleoproteins (U snRNPs) are the building units of the spliceosome. These RNA and protein complexes assemble in the cytoplasm. After proper assembly and RNA maturation, mature U snRNPs are imported into the cell nucleus, where they take part in the splicing process. In this paper we review the current knowledge of how U snRNPs enter the nucleus.

An alternative hypothesis for the deformation of a cell nucleus

Scilight ◽  
2022 ◽  
Vol 2022 (1) ◽  
pp. 011106
Author(s):  
Avery Thompson
Keyword(s):  
Cell Nucleus ◽  
Alternative Hypothesis ◽  
A Cell

scholarly journals Xenopus LAP2β protein knockdown affects location of lamin B and nucleoporins and has effect on assembly of cell nucleus and cell viability

PROTOPLASMA ◽  
2015 ◽  
Vol 253 (3) ◽  
pp. 943-956 ◽  
Author(s):  
Magda Dubińska-Magiera ◽  
Magdalena Chmielewska ◽  
Katarzyna Kozioł ◽  
Magdalena Machowska ◽  
Christopher J. Hutchison ◽  
...  
Keyword(s):  
Cell Death ◽  
Protein Expression ◽  
Nuclear Envelope ◽  
Cell Viability ◽  
Cell Nucleus ◽  
Chromatin Structure ◽  
Integral Membrane Proteins ◽  
Nuclear Abnormalities ◽  
Lamin B ◽  
A Cell

Abstract Xenopus LAP2β protein is the single isoform expressed in XTC cells. The protein localizes on heterochromatin clusters both at the nuclear envelope and inside a cell nucleus. The majority of XLAP2β fraction neither colocalizes with TPX2 protein during interphase nor can be immunoprecipitated with XLAP2β antibody. Knockdown of the XLAP2β protein expression in XTC cells by synthetic siRNA and plasmid encoded siRNA resulted in nuclear abnormalities including changes in shape of nuclei, abnormal chromatin structure, loss of nuclear envelope, mislocalization of integral membrane proteins of INM such as lamin B2, mislocalization of nucleoporins, and cell death. Based on timing of cell death, we suggest mechanism associated with nucleus reassembly or with entry into mitosis. This confirms that Xenopus LAP2 protein is essential for the maintenance of cell nucleus integrity and the process of its reassembly after mitosis.

scholarly journals Ca2+-Induced Ca2+ Release through Localized Ca2+ Uncaging in Smooth Muscle

2006 ◽  
Vol 127 (3) ◽  
pp. 225-235 ◽  
Author(s):  
Guangju Ji ◽  
Morris Feldman ◽  
Robert Doran ◽  
Warren Zipfel ◽  
Michael I. Kotlikoff
Keyword(s):  
Smooth Muscle ◽  
Flash Photolysis ◽  
High Threshold ◽  
Bladder Smooth Muscle ◽  
Two Photon ◽  
Biophysical Processes ◽  
Urinary Bladder Smooth Muscle ◽  
Ca2 Channels ◽  
Kinetic Features

Ca2+-induced Ca2+ release (CICR) from the sarcoplasmic reticulum (SR) occurs in smooth muscle as spontaneous SR Ca2+ release or Ca2+ sparks and, in some spiking tissues, as Ca2+ release that is triggered by the activation of sarcolemmal Ca2+ channels. Both processes display spatial localization in that release occurs at a higher frequency at specific subcellular regions. We have used two-photon flash photolysis (TPFP) of caged Ca2+ (DMNP-EDTA) in Fluo-4–loaded urinary bladder smooth muscle cells to determine the extent to which spatially localized increases in Ca2+ activate SR release and to further understand the molecular and biophysical processes underlying CICR. TPFP resulted in localized Ca2+ release in the form of Ca2+ sparks and Ca2+ waves that were distinguishable from increases in Ca2+ associated with Ca2+ uncaging, unequivocally demonstrating that Ca2+ release occurs subsequent to a localized rise in [Ca2+]i. TPFP-triggered Ca2+ release was not constrained to a few discharge regions but could be activated at all areas of the cell, with release usually occurring at or within several microns of the site of photolysis. As expected, the process of CICR was dominated by ryanodine receptor (RYR) activity, as ryanodine abolished individual Ca2+ sparks and evoked release with different threshold and kinetics in FKBP12.6-null cells. However, TPFP CICR was not completely inhibited by ryanodine; Ca2+ release with distinct kinetic features occurred with a higher TPFP threshold in the presence of ryanodine. This high threshold release was blocked by xestospongin C, and the pharmacological sensitivity and kinetics were consistent with CICR release at high local [Ca2+]i through inositol trisphosphate (InsP3) receptors (InsP3Rs). We conclude that CICR activated by localized Ca2+ release bears essential similarities to those observed by the activation of ICa (i.e., major dependence on the type 2 RYR), that the release is not spatially constrained to a few specific subcellular regions, and that Ca2+ release through InsP3R can occur at high local [Ca2+]i.

Sign in / Sign up

Export Citation Format

Share Document