Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
???displayArticle.abstract???
The particle state of U snRNPs was analyzed in oocytes, eggs, embryos and testes from Xenopus laevis. In each case both the relative abundance and the composition of some U snRNPs were found to differ from that of somatic cells. U2 and U6 snRNPs were the most prominent U snRNPs in germ cells and early embryos. In particular, the concentration of U6 snRNA was 10-20 times higher than that of U4 snRNA. Most of the U6 snRNA was not associated with U4 snRNA and migrated on sucrose gradients as a U6 snRNP. The structure of this novel U snRNP was analyzed. A single protein of 50 kd was copurified with U6 snRNPs by a combination of gradient fractionation, immunodepletion with anti-Sm antibodies and immunoprecipitation with anti-6-methyl adenosine antibodies. Although the U6 snRNP did not contain Sm proteins it migrated into the nucleus when U6 snRNA was injected into the cytoplasm of oocytes. Two U6 snRNA elements have been identified. The first is essential for nuclear migration in oocytes, but not for the formation of U4/6 snRNPs in vitro and might be the binding site of a U6-specific protein. The second element was required for interaction with U4 snRNPs but not for nuclear targeting.
Bach,
20S small nuclear ribonucleoprotein U5 shows a surprisingly complex protein composition.
1989, Pubmed
Bach,
20S small nuclear ribonucleoprotein U5 shows a surprisingly complex protein composition.
1989,
Pubmed Black,
Pre-mRNA splicing in vitro requires intact U4/U6 small nuclear ribonucleoprotein.
1986,
Pubmed Bringmann,
Antibodies specific for N6-methyladenosine react with intact snRNPs U2 and U4/U6.
1987,
Pubmed Bringmann,
Evidence for the existence of snRNAs U4 and U6 in a single ribonucleoprotein complex and for their association by intermolecular base pairing.
1984,
Pubmed Brow,
Spliceosomal RNA U6 is remarkably conserved from yeast to mammals.
1988,
Pubmed Carbon,
A common octamer motif binding protein is involved in the transcription of U6 snRNA by RNA polymerase III and U2 snRNA by RNA polymerase II.
1987,
Pubmed
,
Xenbase Cheng,
Spliceosome assembly in yeast.
1987,
Pubmed De Robertis,
Intracellular transport of microinjected 5S and small nuclear RNAs.
1982,
Pubmed
,
Xenbase Dignam,
Accurate transcription initiation by RNA polymerase II in a soluble extract from isolated mammalian nuclei.
1983,
Pubmed Doetschman,
The in vitro development of blastocyst-derived embryonic stem cell lines: formation of visceral yolk sac, blood islands and myocardium.
1985,
Pubmed Forbes,
Differential expression of multiple U1 small nuclear RNAs in oocytes and embryos of Xenopus laevis.
1984,
Pubmed
,
Xenbase Guthrie,
Spliceosomal snRNAs.
1988,
Pubmed Habets,
Small nuclear RNA-associated proteins are immunologically related as revealed by mapping of autoimmune reactive B-cell epitopes.
1989,
Pubmed Habets,
Autoantibodies to ribonucleoprotein particles containing U2 small nuclear RNA.
1985,
Pubmed Hamm,
Functional analysis of mutant Xenopus U2 snRNAs.
1989,
Pubmed
,
Xenbase Hamm,
In vitro assembly of U1 snRNPs.
1987,
Pubmed
,
Xenbase Hashimoto,
U4 and U6 RNAs coexist in a single small nuclear ribonucleoprotein particle.
1984,
Pubmed Lamond,
Spliceosome assembly involves the binding and release of U4 small nuclear ribonucleoprotein.
1988,
Pubmed Leff,
Complex transcriptional units: diversity in gene expression by alternative RNA processing.
1986,
Pubmed Lerner,
Monoclonal antibodies to nucleic acid-containing cellular constituents: probes for molecular biology and autoimmune disease.
1981,
Pubmed
,
Xenbase Lossky,
Identification of a yeast snRNP protein and detection of snRNP-snRNP interactions.
1987,
Pubmed Lund,
The transcription of Xenopus laevis embryonic U1 snRNA genes changes when oocytes mature into eggs.
1987,
Pubmed
,
Xenbase Lund,
Differential control of U1 small nuclear RNA expression during mouse development.
1985,
Pubmed Lund,
Differential accumulation of U1 and U4 small nuclear RNAs during Xenopus development.
1987,
Pubmed
,
Xenbase Mattaj,
Cap trimethylation of U snRNA is cytoplasmic and dependent on U snRNP protein binding.
1986,
Pubmed
,
Xenbase Mattaj,
Regulated splicing in early development and stage-specific U snRNPs.
1989,
Pubmed Newport,
A major developmental transition in early Xenopus embryos: I. characterization and timing of cellular changes at the midblastula stage.
1982,
Pubmed
,
Xenbase Noble,
Splicing of SV40 early pre-mRNA to large T and small t mRNAs utilizes different patterns of lariat branch sites.
1987,
Pubmed
,
Xenbase Parker,
Recognition of the TACTAAC box during mRNA splicing in yeast involves base pairing to the U2-like snRNA.
1987,
Pubmed Pikielny,
Electrophoresis of ribonucleoproteins reveals an ordered assembly pathway of yeast splicing complexes.
,
Pubmed Pikielny,
In vitro reconstitution of snRNPs: a reconstituted U4/U6 snRNP participates in splicing complex formation.
1989,
Pubmed Rinke,
Localization of a base-paired interaction between small nuclear RNAs U4 and U6 in intact U4/U6 ribonucleoprotein particles by psoralen cross-linking.
1985,
Pubmed Rinke,
Association of the lupus antigen La with a subset of U6 snRNA molecules.
1985,
Pubmed Zhuang,
A compensatory base change in U1 snRNA suppresses a 5' splice site mutation.
1986,
Pubmed Zieve,
Newly synthesized small nuclear RNAs appear transiently in the cytoplasm.
1988,
Pubmed
