Results 251 to 260 of about 25,036 (270)

Structure and assembly of the spliceosomal small nuclear ribonucleoprotein particles

Current Opinion in Structural Biology, 1999
The spliceosome is a macromolecular assembly that carries out the excision of introns from nuclear pre-mRNAs. It consists of four large RNA-protein complexes, called the U1, U2, U4/U6 and U5 small nuclear ribonucleoproteins (snRNPs), and many protein factors.
C, Kambach, S, Walke, K, Nagai
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Purification of small nuclear ribonucleoprotein particles with antibodies against modified nucleosides of small nuclear RNAs

1990
Publisher Summary The snRNAs exist in the cell as ribonucleoprotein (RNP) complexes. While the snRNAs U1, U2, and U5 are organized in separate RNP particles, the majority of the snRNAs U4 and U6 reside in a single RNP complex. Several proteins in the molecular weight range of 25K to 200K were recently identified as possible U5-specific proteins ...
M, Bach, P, Bringmann, R, Lührmann
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Saccharomyces cerevisiae telomerase is an Sm small nuclear ribonucleoprotein particle

Nature, 1999
Activation of the chromosome end-replicating enzyme telomerase can greatly extend the lifespan of normal human cells and is associated with most human cancers. In all eukaryotes examined, telomerase has an RNA subunit, a conserved reverse transcriptase subunit and additional proteins, but little is known about the assembly of these components.
A G, Seto, A J, Zaug, S G, Sobel, S L, Wolin, T R, Cech   +4 more
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Interactions between small nuclear ribonucleoprotein particles in formation of spliceosomes

Cell, 1987
Electrophoretic separation of ribonucleoprotein particles in a nondenaturing gel was used to analyze the splicing of mRNA precursors. Early in the reaction, a complex formed consisting of the U2 small nuclear ribonucleoprotein particle (snRNP) bound to sequences upstream of the 3' splice site. This complex is modeled as a precursor of a larger complex,
M M, Konarska, P A, Sharp
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Ribonucleoprotein organization of eukaryotic RNA. XXXI. Structure of the U1 small nuclear ribonucleoprotein.

Journal of molecular biology, 1985
A small nuclear ribonucleoprotein, U1 snRNP, has been implicated in mRNA processing. In this investigation sites of protein binding on U1 RNA were mapped by nuclease protection and RNA sequencing. Partially purified human U1 snRNP was sequentially digested with Escherichia coli RNAase III and S1 nuclease.
W L, Lin, T, Pederson
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Autoantibodies against small nuclear ribonucleoprotein components.

The Journal of rheumatology. Supplement, 1987
Sera from patients with systemic rheumatic diseases often contain antibodies against nuclear antigens. Among these are proteins complexed with the small nuclear RNA (snRNA) U1, U2, U4, U5 and U6. In human cells, at least 11 different polypeptides (called 70K, A, A', B', B", B, C, D, E, F and G) ranging in molecular weight from 70 to 11 kDa, are ...
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Are U4 small nuclear ribonucleoproteins involved in polyadenylation?

Nature, 1984
The mechanism whereby eukaryotic pre-messenger RNAs are polyadenylated is unknown. Most models for polyadenylation invoke cleavage of precursor transcripts at the site of poly(A) addition followed by polymerization of A residues by poly(A) polymerase. Analysis of the sequences surrounding poly(A) addition sites has identified the consensus recognition ...
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Peptide autoantigenicity of the small nuclear ribonucleoprotein C.

Clinical and experimental rheumatology, 1995
This study determines the antigenic regions of the nRNP C lupus autoantigen.Twenty-one anti-nRNP C sera, six patients with other autoimmune serology, and five normal control sera were assessed for binding with the overlapping octapeptides of the nRNP C protein.
J A, James, J B, Harley
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Autoantigens contained in the U1 small nuclear ribonucleoprotein complex

1994
The U1 snRNP particle contains the following antigenic components: the specific proteins U1-A, U1–70K and U1-C, of which the U1–70K and the Ul-A polypeptides are the major targets of human autoantibodies (reviewed in [1]) Ul snRNA [2, 3].
Jacqueline M. T. Klein Gunnewiek, Walther J. Van Venrooij   +1 more
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Purification of small nuclear ribonucleoprotein particles active in RNA processing

1990
Publisher Summary The snRNPs are localized in the nucleoplasm, except for U3 and possibly U8 snRNPs which reside in the nucleolus. Each particle consists of a uridine-rich RNA, which is associated with several proteins. Except for U3, the snRNPs are immunoprecipitated with antibodies from patients suffering from connective tissue diseases.
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