scholarly journals Nuclear exchange of the U1 and U2 snRNP-specific proteins.

1990 ◽  
Vol 110 (4) ◽  
pp. 871-881 ◽  
Author(s):  
R J Feeney ◽  
G W Zieve
Keyword(s):  
Common Core ◽  
Kinetic Studies ◽  
Isotopic Labeling ◽  
Cell Fractionation ◽  
Isolated Nuclei ◽  
Core Proteins ◽  
U2 Snrnp ◽  
Specific Proteins ◽  
The Common ◽  
Nuclear Exchange

The snRNP particles include a set of common core snRNP proteins and snRNP specific proteins. In rodent cells the common core proteins are the B, D, D', E, F and G proteins in a suggested stoichiometry of B2D'2D2EFG. The additional U1- and U2-specific proteins are the 70-kD, A and C proteins and the A' and B" proteins, respectively. Previous cell fractionation and kinetic analysis demonstrated the snRNP core proteins are stored in the cytoplasm in large partially assembled snRNA-free intermediates that assemble with newly synthesized snRNAs during their transient appearance in the cytoplasm (Sauterer, R. A., R. J. Feeney, and G. W. Zieve. 1988. Exp. Cell Res. 176:344-359). This report investigates the assembly and intracellular distribution of the U1 and U2 snRNP-specific proteins. Cell enucleation and aqueous cell fractionation are used to prepare nuclear and cytoplasmic fractions and the U1- and U2-specific proteins are identified by isotopic labeling and immunoprecipitation or by immunoblotting with specific autoimmune antisera. The A, C, and A' proteins are found both assembled into mature nuclear snRNP particles and in unassembled pools in the nucleus that exchange with the assembled snRNP particles. The unassembled proteins leak from isolated nuclei prepared by detergent extraction. The unassembled A' protein sediments at 4S-6S in structures that may be multimers. The 70-kD and B" proteins are fully assembled with snRNP particles which do not leak from isolated nuclei. The kinetic studies suggest that the B" protein assembles with the U2 particle in the cytoplasm before it enters the nucleus.

Structure of spliceosomal UsnRNPs

1992 ◽  
Vol 50 (1) ◽  
pp. 460-461
Author(s):  
Reinhard Lührmann ◽  
Sven-Erik Behrens ◽  
Berthold Kastner
Keyword(s):  
Immunoaffinity Chromatography ◽  
Mrna Splicing ◽  
Splicing Factors ◽  
Nuclear Extracts ◽  
U2 Snrnp ◽  
Specific Proteins ◽  
The Common ◽  
The Individual ◽  
Stable Formation

The major snRNPs, Ul, U2, U4/U6 and U5, are essential trans-acting factors in the pre-mRNA splicing process. They assemble with a pre-mRNA and a number of other non-snRNP splicing factors prior to the splicing reaction to form an active spliceosome. We are interested in investigating the biochemical composition of UsnRNPs and their ultrastructure as well as their function in splicing. In HeLa cell nuclear extracts the spliceosomal UsnRNPs exhibit differential association behaviour depending on the salt concentration. Thus, at high salt (420 mM) the majority of the Ul, U2, U4/U6 snRNPs migrates on sucrose gradients at 10-12S, while U5 snRNP sediments at 20S. Under in vitro splicing conditions (i.e. at about 100 mM salt), U5 and U4/U6 snRNPs form a 25 S [U4/U6.U5]tri-snRNP-complex and U2 snRNPs sediment at about 17 S.We have isolated the various types of UsnRNPs under native conditions using mainly immunoaffinity chromatography procedures. Today we can distinguish more than 35 distinct snRNP proteins. They can be grouped into two classes. The first class comprises eight common snRNP proteins which are present in each of the spliceosomal UsnRNPs. In addition, the individual snRNPs contain snRNP-specific proteins. These include three (70k, A, C) for the 12 S Ul snRNP, two (A′, B″ for the 12 S U2 snRNP, an additional eight for the 17 S U2 snRNP and eight for the 20 S U5 snRNP. The 25 S [U4/U6.U5]tri-snRNP-complex contains, in addition to the common proteins and the U5-specific proteins, a third group of six proteins which are essential for the stable formation of the tri-snRNP-complex. Thus, the different S-values of a particular snRNP particle result from differences in the population of snRNP-specific proteins associated with that particle.

O ENSINO RELIGIOSO EM QUESTÃO

2018 ◽  
Vol 9 (21) ◽  
pp. 459
Author(s):  
Mauro Rocha Baptista
Keyword(s):  
Supreme Court ◽  
Religious Education ◽  
Common Core ◽  
Historical Perspective ◽  
National Curriculum ◽  
The Other ◽  
Federal Constitution ◽  
The Supreme Court ◽  
The Common

Neste artigo analisamos a relação do Ensino Religioso com a sua evolução ao longo do contexto recente do Brasil para compreender a posição do Supremo Tribunal Federal ao considerar a possibilidade do Ensino Religioso confessional. Inicialmente apresentaremos a perspectiva legislativa criada com a constituição de 1988 e seus desdobramentos nas indicações curriculares. Neste contexto é frisado a intenção de incluir o Ensino Religioso na Base Nacional Curricular Comum, o que acabou não acontecendo. A tendência manifesta nas duas primeiras versões da BNCC era de um Ensino Religioso não-confessional. Uma tendência que demarcava a função do Ensino Religioso em debater a religião, mas que não permitia o direcionamento por uma vertente religioso qualquer. Esta posição se mostrava uma evolução da primeira perspectiva histórica mais associada à catequese confessional. Assim como também ultrapassava a interpretação posterior de um ecumenismo interconfessional, que mantinha a superioridade do cristianismo ante as demais religiões. Sendo assim, neste artigo, adotaremos o argumento de que a decisão do STF, de seis votos contra cinco, acaba retrocedendo ante o que nos parecia um caminho muito mais frutífero.Palavras-chave: Ensino Religioso. Supremo Tribunal Federal. Confessional. Interconfessional. Não-confessional.Abstract: On this article, we analyze the relation between Religious education and its evolution along the currently Brazilian context in order to understand the position of the Supreme Court in considering the possibility of a confessional Religious education. Firstly, we are going to present the legislative perspective created with the 1988 Federal Constitution and its impacts in the curricular lines. On this context it was highlighted the intention to include the Religious Education on the Common Core National Curriculum (CCNC), which did not really happened. The tendency manifested in the first two versions of the CCNC was of a non-confessional Religious Education. A tendency that delineated the function of the Religious Education as debating religion, but not giving direction on any religious side. This position was an evolution of the first historical perspective more associated to the confessional catechesis. It also went beyond the former interpretation of an inter-confessional ecumenism, which kept the superiority of the Christianity over the other religions. As such, in this paper we adopt the argument that the decision of the Supreme Court, of six votes against five, is a reversal of what seemed to be a much more productive path on the Religious Education.Keywords: Religious Education. Brazilian Supreme Court. Confessional. Inter-confessional. Non- confessional.Enviado: 23-01-2018 - Aprovado e publicado: 12-2018

Challenging the Research Base of the Common Core State Standards

2013 ◽  
Vol 42 (7) ◽  
pp. 381-391 ◽  
Author(s):  
David A. Gamson ◽  
Xiaofei Lu ◽  
Sarah Anne Eckert
Keyword(s):  
Common Core ◽  
Common Core State Standards ◽  
State Standards ◽  
Core State ◽  
The Common
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