scholarly journals RNA-protein interactions in the nuclei of Xenopus oocytes: complex formation and processing activity on the regulatory intron of ribosomal protein gene L1.

1994 ◽  
Vol 14 (10) ◽  
pp. 6975-6982 ◽  
Author(s):  
B Santoro ◽  
E De Gregorio ◽  
E Caffarelli ◽  
I Bozzoni
Keyword(s):  
Ribosomal Protein ◽  
Protein Interactions ◽  
Ribosomal Protein Gene ◽  
Small Nucleolar Rna ◽  
Gene Encoding ◽  
Hnrnp C ◽  
Processing Activity ◽  
Low Efficiency ◽  
Nucleolar Rna

The gene encoding ribosomal protein L1 in Xenopus laevis is known to be posttranscriptionally regulated; the third intron can be processed from the pre-mRNA in two alternative ways, resulting either in the production of L1 mRNA or in the release of a small nucleolar RNA (U16). The formation of splicing complexes was studied in vivo by oocyte microinjection. We show that spliceosome assembly is impaired on the L1 third intron and that the low efficiency of the process is due to the presence of suboptimal consensus sequences. An analysis of heterogeneous nuclear ribonucleoprotein (hnRNP) distribution was also performed, revealing a distinct site for hnRNP C binding proximal to the 5' end of the L1 third intron. Cleavage, leading to the production of the small nucleolar RNA U16, occurs in the same position, and we show that conditions under which hnRNP C binding is reduced result in an increase of the processing activity of the intron.

RNA-protein interactions in the nuclei of Xenopus oocytes: complex formation and processing activity on the regulatory intron of ribosomal protein gene L1

1994 ◽  
Vol 14 (10) ◽  
pp. 6975-6982
Author(s):  
B Santoro ◽  
E De Gregorio ◽  
E Caffarelli ◽  
I Bozzoni
Keyword(s):  
Ribosomal Protein ◽  
Protein Interactions ◽  
Ribosomal Protein Gene ◽  
Small Nucleolar Rna ◽  
Gene Encoding ◽  
Hnrnp C ◽  
Processing Activity ◽  
Low Efficiency ◽  
Nucleolar Rna

The gene encoding ribosomal protein L1 in Xenopus laevis is known to be posttranscriptionally regulated; the third intron can be processed from the pre-mRNA in two alternative ways, resulting either in the production of L1 mRNA or in the release of a small nucleolar RNA (U16). The formation of splicing complexes was studied in vivo by oocyte microinjection. We show that spliceosome assembly is impaired on the L1 third intron and that the low efficiency of the process is due to the presence of suboptimal consensus sequences. An analysis of heterogeneous nuclear ribonucleoprotein (hnRNP) distribution was also performed, revealing a distinct site for hnRNP C binding proximal to the 5' end of the L1 third intron. Cleavage, leading to the production of the small nucleolar RNA U16, occurs in the same position, and we show that conditions under which hnRNP C binding is reduced result in an increase of the processing activity of the intron.

scholarly journals Identification of the sequences responsible for the splicing phenotype of the regulatory intron of the L1 ribosomal protein gene of Xenopus laevis.

1992 ◽  
Vol 12 (3) ◽  
pp. 1117-1125 ◽  
Author(s):  
P Fragapane ◽  
E Caffarelli ◽  
M Lener ◽  
S Prislei ◽  
B Santoro ◽  
...  
Keyword(s):  
Xenopus Laevis ◽  
Ribosomal Protein ◽  
Protein Gene ◽  
Ribosomal Protein Gene ◽  
Nuclear Extract ◽  
Wild Type ◽  
Hela Nuclear Extract ◽  
Low Efficiency

Splicing of the regulated third intron of the L1 ribosomal protein gene of Xenopus laevis has been studied in vivo by oocyte microinjection of wild-type and mutant SP6 precursor RNAs and in vitro in the heterologous HeLa nuclear extract. We show that two different phenomena combine to produce the peculiar splicing phenotype of this intron. One, which can be defined constitutive, shows the same features in the two systems and leads to the accumulation of spliced mRNA, but in very small amounts. The low efficiency of splicing is due to the presence of a noncanonical 5' splice site which acts in conjunction with sequences present in the 3' portion of the intron. The second leads to the massive conversion of the pre-mRNA into site specific truncated molecules. This has the effect of decreasing the concentration of the pre-mRNA available for splicing. We show that this aberrant cleavage activity occurs only in the in vivo oocyte system and depends on the presence of an intact U1 RNA.

Identification of the sequences responsible for the splicing phenotype of the regulatory intron of the L1 ribosomal protein gene of Xenopus laevis

1992 ◽  
Vol 12 (3) ◽  
pp. 1117-1125
Author(s):  
P Fragapane ◽  
E Caffarelli ◽  
M Lener ◽  
S Prislei ◽  
B Santoro ◽  
...  
Keyword(s):  
Xenopus Laevis ◽  
Ribosomal Protein ◽  
Protein Gene ◽  
Ribosomal Protein Gene ◽  
Nuclear Extract ◽  
Wild Type ◽  
Hela Nuclear Extract ◽  
Low Efficiency

Splicing of the regulated third intron of the L1 ribosomal protein gene of Xenopus laevis has been studied in vivo by oocyte microinjection of wild-type and mutant SP6 precursor RNAs and in vitro in the heterologous HeLa nuclear extract. We show that two different phenomena combine to produce the peculiar splicing phenotype of this intron. One, which can be defined constitutive, shows the same features in the two systems and leads to the accumulation of spliced mRNA, but in very small amounts. The low efficiency of splicing is due to the presence of a noncanonical 5' splice site which acts in conjunction with sequences present in the 3' portion of the intron. The second leads to the massive conversion of the pre-mRNA into site specific truncated molecules. This has the effect of decreasing the concentration of the pre-mRNA available for splicing. We show that this aberrant cleavage activity occurs only in the in vivo oocyte system and depends on the presence of an intact U1 RNA.

Yeast ribosomal protein L1 is required for the stability of newly synthesized 5S rRNA and the assembly of 60S ribosomal subunits

1993 ◽  
Vol 13 (5) ◽  
pp. 2835-2845
Author(s):  
M Deshmukh ◽  
Y F Tsay ◽  
A G Paulovich ◽  
J L Woolford
Keyword(s):  
Ribosomal Protein ◽  
Ribosomal Subunit ◽  
Single Copy ◽  
5S Rrna ◽  
Gene Encoding ◽  
Ribosomal Subunits ◽  
Ribosomal Protein L1 ◽  
The Stability ◽  
And Function

Ribosomal protein L1 from Saccharomyces cerevisiae binds 5S rRNA and can be released from intact 60S ribosomal subunits as an L1-5S ribonucleoprotein (RNP) particle. To understand the nature of the interaction between L1 and 5S rRNA and to assess the role of L1 in ribosome assembly and function, we cloned the RPL1 gene encoding L1. We have shown that RPL1 is an essential single-copy gene. A conditional null mutant in which the only copy of RPL1 is under control of the repressible GAL1 promoter was constructed. Depletion of L1 causes instability of newly synthesized 5S rRNA in vivo. Cells depleted of L1 no longer assemble 60S ribosomal subunits, indicating that L1 is required for assembly of stable 60S ribosomal subunits but not 40S ribosomal subunits. An L1-5S RNP particle not associated with ribosomal particles was detected by coimmunoprecipitation of L1 and 5S rRNA. This pool of L1-5S RNP remained stable even upon cessation of 60S ribosomal subunit assembly by depletion of another ribosomal protein, L16. Preliminary results suggest that transcription of RPL1 is not autogenously regulated by L1.

scholarly journals A Novel Methyltransferase Methylates Cucumber Mosaic Virus 1a Protein and Promotes Systemic Spread

2008 ◽  
Vol 82 (10) ◽  
pp. 4823-4833 ◽  
Author(s):  
Min Jung Kim ◽  
Sung Un Huh ◽  
Byung-Kook Ham ◽  
Kyung-Hee Paek
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Protein Interactions ◽  
Protein Localization ◽  
Binding Activity ◽  
Virus Infectivity ◽  
Gene Encoding ◽  
Systemic Spread

ABSTRACT In mammalian and yeast systems, methyltransferases have been implicated in the regulation of diverse processes, such as protein-protein interactions, protein localization, signal transduction, RNA processing, and transcription. The Cucumber mosaic virus (CMV) 1a protein is essential not only for virus replication but also for movement. Using a yeast two-hybrid system with tobacco plants, we have identified a novel gene encoding a methyltransferase that interacts with the CMV 1a protein and have designated this gene Tcoi1 (tobacco CMV 1a-interacting protein 1). Tcoi1 specifically interacted with the methyltransferase domain of CMV 1a, and the expression of Tcoi1 was increased by CMV inoculation. Biochemical studies revealed that the interaction of Tcoi1 with CMV 1a protein was direct and that Tcoi1 methylated CMV 1a protein both in vitro and in vivo. The CMV 1a binding activity of Tcoi1 is in the C-terminal domain, which shows the methyltransferase activity. The overexpression of Tcoi1 enhanced the CMV infection, while the reduced expression of Tcoi1 decreased virus infectivity. These results suggest that Tcoi1 controls the propagation of CMV through an interaction with the CMV 1a protein.

A novel small nucleolar RNA (U16) is encoded inside a ribosomal protein intron and originates by processing of the pre-mRNA.

1993 ◽  
Vol 12 (7) ◽  
pp. 2921-2928 ◽  
Author(s):  
P. Fragapane ◽  
S. Prislei ◽  
A. Michienzi ◽  
E. Caffarelli ◽  
I. Bozzoni
Keyword(s):  
Ribosomal Protein ◽  
Small Nucleolar Rna ◽  
Nucleolar Rna

scholarly journals Acquired ribosomopathies in leukemia and solid tumors

Hematology ◽  
2017 ◽  
Vol 2017 (1) ◽  
pp. 716-719 ◽  
Author(s):  
Adrianna Vlachos
Keyword(s):  
Bone Marrow ◽  
Ribosomal Protein ◽  
Solid Tumors ◽  
Ribosomal Proteins ◽  
Bone Marrow Failure ◽  
Ribosomal Protein Gene ◽  
Small Subunit ◽  
Gene Encoding ◽  
Bone Marrow Failure Syndrome ◽  
Diamond Blackfan Anemia

AbstractA mutation in the gene encoding the small subunit-associated ribosomal protein RPS19, leading to RPS19 haploinsufficiency, is one of the ribosomal protein gene defects responsible for the rare inherited bone marrow failure syndrome Diamond Blackfan anemia (DBA). Additional inherited and acquired defects in ribosomal proteins (RPs) continue to be identified and are the basis for a new class of diseases called the ribosomopathies. Acquired RPS14 haploinsufficiency has been found to be causative of the bone marrow failure found in 5q– myelodysplastic syndromes. Both under- and overexpression of RPs have also been implicated in several malignancies. This review will describe the somatic ribosomopathies that have been found to be associated with a variety of solid tumors as well as leukemia and will review cancers in which over- or underexpression of these proteins seem to be associated with outcome.

scholarly journals Yeast snR30 is a small nucleolar RNA required for 18S rRNA synthesis.

1993 ◽  
Vol 13 (4) ◽  
pp. 2469-2477 ◽  
Author(s):  
J P Morrissey ◽  
D Tollervey
Keyword(s):  
18S Rrna ◽  
Progressive Increase ◽  
Rrna Synthesis ◽  
Rrna Processing ◽  
Small Nucleolar Rna ◽  
Conditional Allele ◽  
Cell Doubling Time ◽  
Associated Proteins ◽  
Nucleolar Rna

Subnuclear fractionation and coprecipitation by antibodies against the nucleolar protein NOP1 demonstrate that the essential Saccharomyces cerevisiae RNA snR30 is localized to the nucleolus. By using aminomethyl trimethyl-psoralen, snR30 can be cross-linked in vivo to 35S pre-rRNA. To determine whether snR30 has a role in rRNA processing, a conditional allele was constructed by replacing the authentic SNR30 promoter with the GAL10 promoter. Repression of snR30 synthesis results in a rapid depletion of snR30 and a progressive increase in cell doubling time. rRNA processing is disrupted during the depletion of snR30; mature 18S rRNA and its 20S precursor underaccumulate, and an aberrant 23S pre-rRNA intermediate can be detected. Initial results indicate that this 23S pre-rRNA is the same as the species detected on depletion of the small nucleolar RNA-associated proteins NOP1 and GAR1 and in an snr10 mutant strain. It was found that the 3' end of 23S pre-rRNA is located in the 3' region of ITS1 between cleavage sites A2 and B1 and not, as previously suggested, at the B1 site, snR30 is the fourth small nucleolar RNA shown to play a role in rRNA processing.

scholarly journals Yeast ribosomal protein L1 is required for the stability of newly synthesized 5S rRNA and the assembly of 60S ribosomal subunits.

1993 ◽  
Vol 13 (5) ◽  
pp. 2835-2845 ◽  
Author(s):  
M Deshmukh ◽  
Y F Tsay ◽  
A G Paulovich ◽  
J L Woolford
Keyword(s):  
Ribosomal Protein ◽  
Ribosomal Subunit ◽  
Single Copy ◽  
5S Rrna ◽  
Gene Encoding ◽  
Ribosomal Subunits ◽  
Ribosomal Protein L1 ◽  
The Stability ◽  
And Function

Ribosomal protein L1 from Saccharomyces cerevisiae binds 5S rRNA and can be released from intact 60S ribosomal subunits as an L1-5S ribonucleoprotein (RNP) particle. To understand the nature of the interaction between L1 and 5S rRNA and to assess the role of L1 in ribosome assembly and function, we cloned the RPL1 gene encoding L1. We have shown that RPL1 is an essential single-copy gene. A conditional null mutant in which the only copy of RPL1 is under control of the repressible GAL1 promoter was constructed. Depletion of L1 causes instability of newly synthesized 5S rRNA in vivo. Cells depleted of L1 no longer assemble 60S ribosomal subunits, indicating that L1 is required for assembly of stable 60S ribosomal subunits but not 40S ribosomal subunits. An L1-5S RNP particle not associated with ribosomal particles was detected by coimmunoprecipitation of L1 and 5S rRNA. This pool of L1-5S RNP remained stable even upon cessation of 60S ribosomal subunit assembly by depletion of another ribosomal protein, L16. Preliminary results suggest that transcription of RPL1 is not autogenously regulated by L1.

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