Appearance and origin of snRNP antigens in chick erythrocyte nuclei reactivated in heterokaryons

1990 ◽  
Vol 95 (3) ◽  
pp. 361-370
Author(s):  
M. Bergman ◽  
U. Nyman ◽  
N. Ringertz ◽  
I. Pettersson
Keyword(s):  
Rna Synthesis ◽  
Rna Polymerase Iii ◽  
Molecular Complexes ◽  
The Other ◽  
Small Nuclear Ribonucleoprotein ◽  
Nuclear Antigens ◽  
Low Levels ◽  
Full Intensity ◽  
Nuclear Ribonucleoprotein ◽  
Sm Antigen

Fusion of terminally differentiated chick erythrocytes (CE) with transcriptionally active rat myoblasts results in heterokaryons in which the CE nuclei undergo reactivation of RNA synthesis and splicing. In order to analyze the transport and assembly of small nuclear ribonucleoprotein (snRNP) particles and larger molecular complexes engaged in RNA processing, we have examined CE nuclei in heterokaryons for the presence of four U snRNP-related nuclear antigens (Sm, 70,000 Mr, F78 and M3G-cap) and for one antigen (La), associated with RNA polymerase III transcripts. Inactive erythrocyte nuclei showed low levels of Sm and F78 antigens, but the other antigens were undetectable. Immediately after fusion, the fluorescence of the pre-existing chicken Sm antigen was detected in the CEn, and then the intensity of the signal increased rapidly during reactivation. The other antigens appeared more slowly, reaching full intensity at different time points after fusion. Blocking of chick transcription did not block the appearance of Sm, 70,000 Mr, cap and La antigens but did effectively inhibit the appearance of the F78 antigen. It has previously been demonstrated that the structure recognized by this monoclonal antibody is physically associated with functional splicing complexes. Blocking of translation in heterokaryons abolished uptake of snRNPs into the chicken nuclei. Taken together, the results indicate that rat snRNP complexes were imported into the chick nuclei after assembly in the cytoplasm. For all the studied antigens, except F78, this translocation was independent of chick RNA synthesis. The appearance of the F78 antigen was totally dependent on expression of chicken genes.

scholarly journals In vitro splicing of pre-messenger RNA with extracts from 5-fluorouridine-treated cells

1994 ◽  
Vol 297 (2) ◽  
pp. 297-301 ◽  
Author(s):  
J R Patton
Keyword(s):  
Cell Growth ◽  
Messenger Rna ◽  
Rna Synthesis ◽  
Significant Inhibition ◽  
Small Nuclear Ribonucleoprotein ◽  
Nuclear Extracts ◽  
Specific Step ◽  
In Vitro Splicing ◽  
Nuclear Ribonucleoprotein

The effect of 5-fluorouridine (5-FU) treatment of cells on the splicing of pre-mRNA was determined using cellular extracts and splicing in vitro. Nuclear extracts from control cells and cells treated with 5-FU were prepared and used to splice pre-mRNAs in vitro. The drug treatment resulted in inhibition of cell growth but had little effect on RNA synthesis. The extracts from 5-FU-treated cells showed significant inhibition of splicing. This inhibition was the result of reduced efficiency and was not caused by a block at a specific step in the splicing pathway. There were no observable changes in the levels or physical properties of the small nuclear ribonucleoprotein particles that are essential cofactors in the splicing process. The deficiency in splicing in the extracts from 5-FU-treated cells could be supplemented by the addition of complementary fractions from a control extract.

scholarly journals Nonhistone nuclear antigens reactive with autoantibodies. Immunofluorescence studies on distribution in synchronized cells.

1981 ◽  
Vol 91 (3) ◽  
pp. 654-660 ◽  
Author(s):  
J S Deng ◽  
Y Takasaki ◽  
E M Tan
Keyword(s):  
S Phase ◽  
Lymphoid Cells ◽  
Immunofluorescent Study ◽  
Nuclear Antigens ◽  
Immunofluorescence Studies ◽  
Cell Growth And Differentiation ◽  
B Lymphoid ◽  
Nuclear Ribonucleoprotein ◽  
Indirect Immunofluorescent ◽  
Sm Antigen

Sera from patients with certain autoimmune diseases tht contained autoantibodies to nonhistone nuclear antigens were used as reagents in an indirect immunofluorescent study. The distribution of these nuclear antigens was determined in synchronized human B lymphoid cells. Autoantibodies to Sm antigen, nuclear ribonucleoprotein complex and SS-B antigen were used. Although all three nonhistone antigens appeared to show speckled nuclear straining patterns in the Go phase, different patterns of staining were present at other periods of the cell cycle. The SS-B antigen showed a distinctly nucleolar localization during the G1/early S phase. These studies demonstrate that autoantibodies occurring in certain human diseases can be useful reagents for the immunohistological localization of nuclear macromolecules and for tracing their pathways during different phases of cell growth and differentiation.

Immunolocalization of nuclear antigens in cryofixed cells which have been prepared by molecular distillation drying or freeze-substitution

1990 ◽  
Vol 48 (3) ◽  
pp. 898-899
Author(s):  
David L. Spector ◽  
Robert J. Derby
Keyword(s):  
Cell Nucleus ◽  
Molecular Distillation ◽  
Functional Organization ◽  
Freeze Substitution ◽  
3 Dimensional ◽  
Small Nuclear Ribonucleoprotein ◽  
Nuclear Antigens ◽  
Dimensional Reconstruction ◽  
Nuclear Regions ◽  
Immunoperoxidase Labeling

Studies in our laboratory are involved in evaluating the structural and functional organization of the mammalian cell nucleus. Since several major classes (U1, U2, U4/U6, U5) of small nuclear ribonucleoprotein particles (snRNPs) play a crucial role in the processing of pre-mRNA molecules, we have been interested in the localization of these particles within the cell nucleus. Using pre-embedding immunoperoxidase labeling combined with 3-dimensional reconstruction, we have recently shown that nuclear regions enriched in snRNPs form a reticular network within the nucleoplasm which extends between the nucleolar surface and the nuclear envelope. In the present study we were inte rested in extending these nuclear localizations using cell preparation techniques which avoid slow penetration of fixatives, chemical crosslinking of potential antigens and solvent extraction. CHOC 400 cells were cryofixed using a CF 100 ultra rapid cooling device (LifeCell Corp.). After cryofixation cells were molecular distillation dried, vapor osmicated, in filtra ted in 100% Spurr resin in vacuo and polymerized in molds a t 60°C. Using this procedure we were able to evaluate the distribution of snRNPs in resin embedded cells which had not been chemically fixed, incubated in cryoprotectants or extracted with solvents.

NEUROTIC SYMPTOMATICS RELATED TO PERSONAL CHARACTERISTICS IN YOUTH

2019 ◽  
pp. 2014-2019
Author(s):  
Milen Dimov
Keyword(s):  
Personal Characteristics ◽  
The Self ◽  
The Other ◽  
Social Responsiveness ◽  
Training Process ◽  
Self Assessment ◽  
School Year ◽  
Real Behavior ◽  
Low Levels ◽  
The Ideal

The present study traces the dynamics of personal characteristics in youth and the manifested neurotic symptoms in the training process. These facts are the reason for the low levels of school results in the context of the existing theoretical statements of the problem and the empirical research conducted among the trained teenagers. We suggest that the indicators of neurotic symptomatology in youth – aggression, anxiety, and neuroticism, are the most demonstrated, compared to the other studied indicators of neurotic symptomatology. Studies have proved that there is a difference in the act of neurotic symptoms when tested in different situations, both in terms of expression and content. At the beginning of the school year, neurotic symptoms, more demonstrated in some aspects of aggressiveness, while at the end of school year, psychotism is more demonstrated. The presented summarized results indicate that at the beginning of the school year, neurotic symptoms are strongly associated with aggression. There is a tendency towards a lower level of social responsiveness, both in the self-assessment of real behavior and in the ideal “I”-image of students in the last year of their studies. The neurotic symptomatology, more demonstrated due to specific conditions in the life of young people and in relation to the characteristics of age.

Sign in / Sign up

Export Citation Format

Share Document