Differential Control of U1 Small Nuclear RNA Expression During Mouse Development

Lund, Elsebet; Kahan, Brenda; Dahlberg, James E.

doi:10.1126/science.2412294

Cited by 108 publications

(91 citation statements)

References 28 publications

(11 reference statements)

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“…Measurements of the signal intensities showed that Ul snRNA is -500 times more abundant than U7 RNA in C127 cells, whereas in K21 cells this difference is only 60-fold. Since K21 cells, but not C 127, additionally express the embryonic Ulb RNA at 5-to 10-fold higher levels than U7 RNA (Figure 2;Lund et al, 1985) the overall difference in K21 cells is -65-to 70-fold.…”

Section: Resultsmentioning

confidence: 99%

The low abundance of U7 snRNA is partly determined by its Sm binding site.

1993

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In transient expression studies after DNA transfection of HeLa cells, the mouse U7 gene produces only -30% of the RNA produced by a mouse Ulb gene. This difference persists even when the transfected genes have all their 5' and 3' flanking sequences exchanged suggesting a post-transcriptional effect. When the special U7 Sm binding site is mutated to a consensus derived from the major snRNAs (Sm-opt), the U7 RNA level increases 4-to 5-fold, whereas no RNA is detected from a U7 gene with a non-functional Sm binding site (Smmut). Moreover, Ulb genes with the U7 Sm binding site yield reduced RNA levels. The Sm-opt site also alters the cellular behaviour of the corresponding U7 snRNA. It accumulates to a higher level in the nucleus than wild type U7 RNA, and is better immunoprecipitable with anti-Sm antibodies. Injection experiments in Xenopus oocytes indicate that the U7 genes with either Sm-opt or Sm-mut sites produce similar amounts of RNA as wild type U7, but that they differ in opposing ways in the processing of precursors to mature size U7 snRNA and in nuclear accumulation. However, in reconstitution experiments using Xenopus oocytes, we show that U7 Sm-opt RNA, despite its efficient nuclear accumulation, is not active in 3' processing of histone pre-mRNA, whereas wild type U7 RNA is assembled into functional snRNPs, which correctly process histone pre-mRNA substrate. This suggests a functional importance of the special U7 Sm sequence.

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Section: Resultsmentioning

confidence: 99%

The low abundance of U7 snRNA is partly determined by its Sm binding site.

1993

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“…For analyses of U4 RNAs, we used partially denaturing gels [containing 12% (30:0.8)polyacrylamide, 7 M urea and 1 x TEB; Lund et al 1985] which were found to resolve at least six different forms of xU4 RNAs.…”

Section: Isolation Of Unlabeled Rnas For Northern Blot Analysesmentioning

confidence: 99%

“…erences therein), we and others have proposed that differential expression of snRNA genes during development might be responsible, in part, for selection of alternative splice sites during pre-mRNA processing Lund et al 1985;Laski et al 1986). …”

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confidence: 99%

Differential accumulation of U1 and U4 small nuclear RNAs during Xenopus development.

Lund¹,

Dahlberg²

1987

Genes Dev.

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We showed previously that those U1 small nuclear RNA (snRNA) genes of Xenopus laevis which are transcribed very actively in early embryos are quiescent in mature (stage VI) oocytes . Although that study demonstrated that differential control of snRNA genes occurred, it did not describe snRNA accumulation during development. Using high-resolution polyacrylamide gels in combination with Northern blot hybridization and RNA sequence analyses, we show here that Xenopus has at least three classes of U1 and U4 snRNAs that are distinguishable by their differential expression of oocytes, embryos, tadpoles, and frogs.Adult snRNAs appear to be synthesized constitutively throughout Xenopus development and comprise the major species in tissues from large tadpoles and frogs. Embryonic snRNAs are the principal species accumulating during the two periods of rapid snRNA synthesis, i.e., in previtellogenic oocytes and early embryos. Tadpole RNAs are minor species that are most prominent in young feeding tadpoles. Transcription of both embryonic and adult snRNA genes is activated at the midblastula transition (MBT), but expression of the embryonic genes is switched off selectively within a few days after MBT. Although the precise timing of this inactivation differs significantly for U1 and U4 genes, the overall pattern of differential expression is common to U I and U2 snRNA genes. Because of sequence differences between the snRNAs accumulating at various stages, the resulting populations of snRNPs could have different splice-site specificities leading to altered patterns of pre-mRNA splicing during development.

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“…There is developmentally regulated expression of the mouse Ul Nucleic Acids Research RNAs as well (12). The Ulb RNAs are expressed in early mouse development and in many tumor lines but not in many terminally differentiated cells (12) or in fibroblasts (13).…”

Section: Introductionmentioning

confidence: 99%