The 5′ end of U3 snRNA can be crosslinked in vivo to the external transcribed spacer of rat ribosomal RNA precursors

Stroke, Ilana L.; Weiner, Alan M.

doi:10.1016/0022-2836(89)90126-5

Cited by 91 publications

(55 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This result also supports our concept of the terminal balls, because the U3 snRNP (which contains fibrillarin) has been shown to bind to this 5' ETS processing complex in vitro and to be present on the 5' ETS in the vicinity of this processing site in vivo (Maser and Calvet 1989;Stroke and Weiner 1989).…”

Section: Genes and Developmentsupporting

confidence: 85%

“…This 5' ETS processing also requires the U3 small nuclear ribonucleoprotein (snRNP) ). The mouse processing signal is -85% conserved in human and rat pre-rRNA, starting at residues 422 and 793, respectively, as well as in other mammals, and these regions also direct processing Stroke and Weiner 1989;Tower et al 1989). A report that Xenopus oocyte pre-rRNA does not exhibit processing in its 5' ETS (Savino and Gerbi 1991) spectively; the first 11 nucleotides of these segments are conserved between frog and mammals (boxed residues in the inner diagram; Bourbon et al 1988).…”

mentioning

confidence: 99%

See 1 more Smart Citation

The terminal balls characteristic of eukaryotic rRNA transcription units in chromatin spreads are rRNA processing complexes.

Mougey¹,

O'Reilly²,

Osheim³

et al. 1993

Genes Dev.

167

131

View full text Add to dashboard Cite

When spread chromatin is visualized by electron microscopy, active rRNA genes have a characteristic Christmas tree appearance: From a DNA "trunk" extend closely packed "branches" of nascent transcripts whose ends are decorated with terminal "balls." These terminal balls have been known for more than two decades, are shown in most biology textbooks, and are reported in hundreds of papers, yet their nature has remained elusive. Here, we show that a rRNA-processing signal in the 5'-external transcribed spacer (ETS) of the Xenopus laevis ribosomal primary transcript forms a large, processing-related complex with factors of the Xenopus oocyte, analogous to 5' ETS processing complexes found in other vertebrate cell types. Using mutant rRNA genes, we find that the same rRNA residues are required for this biochemically defined complex formation and for terminal ball formation, analyzed electron microscopically after injection of these cloned genes into Xenopus oocytes. This, plus other presented evidence, implies that rRNA terminal balls in Xenopus, and by inference, also in the multitude of other species where they have been observed, are the uhrastructural visualization of an evolutionarily conserved 5' ETS processing complex that forms on the nascent rRNA.[Key Words: rRNA processing complex; terminal balls; eukaryotic rRNA transcription units; chromatin spreads; X. laevis] Received February 5, 1993; revised version accepted May 21, 1993.One of the earliest, yet still highly informative and much used methods of studying eukaryotic gene expression, is by direct electron microscopic visualization of the transcribing chromatin (Miller and Beatty 1969a). This technique of native chromatin visualization (forming socalled Miller spreads) has facilitated numerous advances in the analysis of gene expression. These include (1) the finding that eukaryotic rRNA genes are organized typically in tandem head-to-tail arrays separated by "nontranscribed spacers" (Miller and Beatty 1969a); (2) the demonstration that the polarity of ribosomal transcription is from 18S to 28S (Reeder et al. 1976), (3) the first analyses of the synchrony of rRNA transcriptional turnon during development Foe 1978;Franke et al. 1979); (4) the first indication of transcription of cloned rRNA genes (Trendelenburg and Gutdon 1978); and (5) the ability to visualize spliceosome complexes on nascent RNA polymerase II-driven transcripts Beyer and Osheim 1988).

show abstract

Section: Genes and Developmentsupporting

confidence: 85%

mentioning

confidence: 99%

The terminal balls characteristic of eukaryotic rRNA transcription units in chromatin spreads are rRNA processing complexes.

Mougey¹,

O'Reilly²,

Osheim³

et al. 1993

Genes Dev.

167

131

View full text Add to dashboard Cite

show abstract

“…In addition, U3 has the potential to base pair with pre-rRNA (4,11) and has been cross-linked in vitro to sites within the 5Ј external transcribed spacer (5Ј ETS) (Fig. 1A) found upstream of 18S in pre-rRNA (31); processing at this site requires the presence of U3 (3). Mutagenesis of this region in rRNA and compensatory changes in U3 in yeast demonstrated that base pairing of U3 to pre-rRNA is essential for efficient accumulation of 18S rRNA (3).…”

mentioning

confidence: 99%

The Sequence of the 5′ End of the U8 Small Nucleolar RNA Is Critical for 5.8S and 28S rRNA Maturation

Peculis

1997

Molecular and Cellular Biology

View full text Add to dashboard Cite

Ribosome biogenesis in eucaryotes involves many small nucleolar ribonucleoprotein particles (snoRNP), a few of which are essential for processing pre-rRNA. Previously, U8 snoRNA was shown to play a critical role in pre-rRNA processing, being essential for accumulation of mature 28S and 5.8S rRNAs. Here, evidence which identifies a functional site of interaction on the U8 RNA is presented. RNAs with mutations, insertions, or deletions within the 5 -most 15 nucleotides of U8 do not function in pre-rRNA processing. In vivo competitions in Xenopus oocytes with 2 O-methyl oligoribonucleotides have confirmed this region as a functional site of a base-pairing interaction. Cross-species hybrid molecules of U8 RNA show that this region of the U8 snoRNP is necessary for processing of pre-rRNA but not sufficient to direct efficient cleavage of the pre-rRNA substrate; the structure or proteins comprising, or recruited by, the U8 snoRNP modulate the efficiency of cleavage. Intriguingly, these 15 nucleotides have the potential to base pair with the 5 end of 28S rRNA in a region where, in the mature ribosome, the 5 end of 28S interacts with the 3 end of 5.8S. The 28S-5.8S interaction is evolutionarily conserved and critical for pre-rRNA processing in Xenopus laevis. Taken together these data strongly suggest that the 5 end of U8 RNA has the potential to bind pre-rRNA and in so doing, may regulate or alter the pre-rRNA folding pathway. The rest of the U8 particle may then facilitate cleavage or recruitment of other factors which are essential for pre-rRNA processing.

show abstract

“…This factor could be nucleolin, which is required to load U3 snoRNP on the pre-rRNA substrate (Ginisty et al 1998). Nucleolin binds to UCGA (Ginisty et al 2000), which is contained in an 11-nt evolutionarily conserved motif GAUCGAUGUGG Stroke and Weiner 1989) located in a single-stranded area of the ETS (Michot and Bachellerie 1991). As depicted in Figure 8, the ETS-binding site of nucleolin on pre-rRNA is near to region E1 that we have demonstrated here base pairs with the 3Ј hinge of U3 snoRNA.…”

Section: U3 Snornp Docking On Pre-rrnamentioning

confidence: 72%

“…Early experiments demonstrated that U3 snoRNA is associated with prerRNA in vertebrates (for review, see Gerbi et al 1990Gerbi et al , 2001Gerbi and Borovjagin 2003). Subsequent psoralen crosslinking experiments indicated that U3 snoRNA is in close proximity to the ETS of pre-rRNA (Maser and Calvet 1989;Stroke and Weiner 1989;Beltrame and Tollervey 1992;Tyc and Steitz 1992;Hartshorne 1998), but the precise site and nature of the association was not fully defined in those studies. Hydrogen bonding contributes to the association of U3 snoRNA with pre-rRNA in vertebrates (Epstein et al 1984), but the location of base-pairing remained unknown.…”

Section: Introductionmentioning

confidence: 98%

Xenopus U3 snoRNA docks on pre-rRNA through a novel base-pairing interaction

Borovjagin

Gerbi²

2004

RNA

View full text Add to dashboard Cite

U3 small nucleolar RNA (snoRNA) is essential for rRNA processing to form 18S ribosomal RNA (rRNA). Previously, it has been shown that nucleolin is needed to load U3 snoRNA on pre-rRNA. However, as documented here, this is not sufficient. We present data that base-pairing between the U3 hinges and the external transcribed spacer (ETS) is critical for functional alignment of U3 on its pre-rRNA substrate. Additionally, the interaction between the U3 hinges and the ETS is proposed to serve as an anchor to hold U3 on the pre-rRNA substrate, while box A at the 5 end of U3 snoRNA swivels from ETS contacts to 18S rRNA contacts. Compensatory base changes revealed base-pairing between the 3 hinge of U3 snoRNA and region E1 of the ETS in Xenopus pre-rRNA; this novel interaction is required for 18S rRNA production. In contrast, base-pairing between the 5 hinge of U3 snoRNA and region E2 of the ETS is auxiliary, unlike the case in yeast where it is required. Thus, higher and lower eukaryotes use different interactions for functional association of U3 with pre-rRNA. The U3 hinge sequence varies between species, but covariation in the ETS retains complementarity. This species-specific U3-pre-rRNA interaction offers a potential target for a new class of antibiotics to prevent ribosome biogenesis in eukaryotic pathogens.

show abstract

The 5′ end of U3 snRNA can be crosslinked in vivo to the external transcribed spacer of rat ribosomal RNA precursors

Cited by 91 publications

References 52 publications

The terminal balls characteristic of eukaryotic rRNA transcription units in chromatin spreads are rRNA processing complexes.

The terminal balls characteristic of eukaryotic rRNA transcription units in chromatin spreads are rRNA processing complexes.

The Sequence of the 5′ End of the U8 Small Nucleolar RNA Is Critical for 5.8S and 28S rRNA Maturation

Xenopus U3 snoRNA docks on pre-rRNA through a novel base-pairing interaction

Contact Info

Product

Resources

About