scholarly journals A U5 small nuclear ribonucleoprotein particle protein involved only in the second step of pre-mRNA splicing in Saccharomyces cerevisiae

1993 ◽  
Vol 13 (5) ◽  
pp. 2959-2970
Author(s):  
D S Horowitz ◽  
J Abelson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Active Form ◽  
Mrna Splicing ◽  
Second Step ◽  
Temperature Sensitive ◽  
Ribonucleoprotein Particle ◽  
Small Nuclear Ribonucleoprotein ◽  
Nuclear Ribonucleoprotein ◽  
Small Nuclear Ribonucleoprotein Particle

The PRP18 gene, which had been identified in a screen for pre-mRNA splicing mutants in Saccharomyces cerevisiae, has been cloned and sequenced. Yeast strains bearing only a disrupted copy of PRP18 are temperature sensitive for growth; even at a low temperature, they grow extremely slowly and do not splice pre-mRNA efficiently. This unusual temperature sensitivity can be reproduced in vitro; extracts immunodepleted of PRP18 are temperature sensitive for the second step of splicing. The PRP18 protein has been overexpressed in active form in Escherichia coli and has been purified to near homogeneity. Antibodies directed against PRP18 precipitate the U4/U5/U6 small nuclear ribonucleoprotein particle (snRNP) from yeast extracts. From extracts depleted of the U6 small nuclear RNA (snRNA), the U4 and U5 snRNAs can be immunoprecipitated, while no snRNAs can be precipitated from extracts depleted of the U5 snRNA. PRP18 therefore appears to be primarily associated with the U5 snRNP. The antibodies against PRP18 inhibit the second step of pre-mRNA splicing in vitro. Together, these results imply that the U5 snRNP plays a role in the second step of splicing and suggest a model for the action of PRP18.

scholarly journals A U5 small nuclear ribonucleoprotein particle protein involved only in the second step of pre-mRNA splicing in Saccharomyces cerevisiae.

1993 ◽  
Vol 13 (5) ◽  
pp. 2959-2970 ◽  
Author(s):  
D S Horowitz ◽  
J Abelson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Active Form ◽  
Mrna Splicing ◽  
Second Step ◽  
Temperature Sensitive ◽  
Ribonucleoprotein Particle ◽  
Small Nuclear Ribonucleoprotein ◽  
Nuclear Ribonucleoprotein ◽  
Small Nuclear Ribonucleoprotein Particle

The PRP18 gene, which had been identified in a screen for pre-mRNA splicing mutants in Saccharomyces cerevisiae, has been cloned and sequenced. Yeast strains bearing only a disrupted copy of PRP18 are temperature sensitive for growth; even at a low temperature, they grow extremely slowly and do not splice pre-mRNA efficiently. This unusual temperature sensitivity can be reproduced in vitro; extracts immunodepleted of PRP18 are temperature sensitive for the second step of splicing. The PRP18 protein has been overexpressed in active form in Escherichia coli and has been purified to near homogeneity. Antibodies directed against PRP18 precipitate the U4/U5/U6 small nuclear ribonucleoprotein particle (snRNP) from yeast extracts. From extracts depleted of the U6 small nuclear RNA (snRNA), the U4 and U5 snRNAs can be immunoprecipitated, while no snRNAs can be precipitated from extracts depleted of the U5 snRNA. PRP18 therefore appears to be primarily associated with the U5 snRNP. The antibodies against PRP18 inhibit the second step of pre-mRNA splicing in vitro. Together, these results imply that the U5 snRNP plays a role in the second step of splicing and suggest a model for the action of PRP18.

scholarly journals PRP4: a protein of the yeast U4/U6 small nuclear ribonucleoprotein particle

1989 ◽  
Vol 9 (9) ◽  
pp. 3710-3719
Author(s):  
J Banroques ◽  
J N Abelson
Keyword(s):  
Essential Role ◽  
Mrna Splicing ◽  
Ribonucleoprotein Particle ◽  
Specific Antibodies ◽  
Small Nuclear Ribonucleoprotein ◽  
Assembly Pathway ◽  
Nuclear Ribonucleoprotein ◽  
Small Nuclear Ribonucleoprotein Particle

The Saccharomyces cerevisiae prp mutants (prp2 through prp11) are known to be defective in pre-mRNA splicing at nonpermissive temperatures. We have sequenced the PRP4 gene and shown that it encodes a 52-kilodalton protein. We obtained PRP4 protein-specific antibodies and found that they inhibited in vitro pre-mRNA splicing, which confirms the essential role of PRP4 in splicing. Moreover, we found that PRP4 is required early in the spliceosome assembly pathway. Immunoprecipitation experiments with anti-PRP4 antibodies were used to demonstrate that PRP4 is a protein of the U4/U6 small nuclear ribonucleoprotein particle (snRNP). Furthermore, the U5 snRNP could be immunoprecipitated through snRNP-snRNP interactions in the large U4/U5/U6 complex.

scholarly journals The yeast PRP6 gene encodes a U4/U6 small nuclear ribonucleoprotein particle (snRNP) protein, and the PRP9 gene encodes a protein required for U2 snRNP binding.

1990 ◽  
Vol 10 (12) ◽  
pp. 6417-6425 ◽  
Author(s):  
N Abovich ◽  
P Legrain ◽  
M Rosbash
Keyword(s):  
Temperature Sensitive ◽  
Ribonucleoprotein Particle ◽  
Small Nuclear Ribonucleoprotein ◽  
U2 Snrnp ◽  
Snrnp Protein ◽  
Yeast Genes ◽  
Nuclear Ribonucleoprotein ◽  
Small Nuclear Ribonucleoprotein Particle

PRP6 and PRP9 are two yeast genes involved in pre-mRNA splicing. Incubation at 37 degrees C of strains that carry temperature-sensitive mutations at these loci inhibits splicing, and in vivo experiments suggested that they might be involved in commitment complex formation (P. Legrain and M. Rosbash, Cell 57:573-583, 1989). To examine the specific role that the PRP6 and PRP9 products may play in splicing or pre-mRNA transport to the cytoplasm, we have characterized in vitro splicing and spliceosome assembly in extracts derived from prp6 and prp9 mutant strains. We have also characterized RNAs that are specifically immunoprecipitated with the PRP6 and PRP9 proteins. Both approaches indicate that PRP6 encodes a U4/U6 small nuclear ribonucleoprotein particle (snRNP) protein and that the PRP9 protein is required for a stable U2 snRNP-substrate interaction. The results are discussed with reference to the previously observed in vivo phenotypes of these mutants.

scholarly journals PRP4 (RNA4) from Saccharomyces cerevisiae: its gene product is associated with the U4/U6 small nuclear ribonucleoprotein particle.

1989 ◽  
Vol 9 (9) ◽  
pp. 3698-3709 ◽  
Author(s):  
S P Bjørn ◽  
A Soltyk ◽  
J D Beggs ◽  
J D Friesen
Keyword(s):  
Gene Product ◽  
Yeast Cells ◽  
Temperature Sensitive ◽  
Ribonucleoprotein Particle ◽  
Direct Role ◽  
Small Nuclear Ribonucleoprotein ◽  
Cloned Gene ◽  
Nuclear Ribonucleoprotein ◽  
Small Nuclear Ribonucleoprotein Particle

The PRP4 (RNA4) gene product is involved in nuclear mRNA processing in yeast cells; we have previously cloned the gene by complementation of a temperature-sensitive mutation. Sequence and transcript analyses of the cloned gene predicted the gene product to be a 52-kilodalton protein, which was confirmed with antibodies raised against the PRP4 gene product. These antibodies inhibited precursor mRNA splicing in vitro, demonstrating a direct role of PRP4 in splicing. Immunoprecipitations with the antibodies indicated that the PRP4 protein is associated with the U4/U6 small nuclear ribonucleoprotein particle.

The yeast PRP6 gene encodes a U4/U6 small nuclear ribonucleoprotein particle (snRNP) protein, and the PRP9 gene encodes a protein required for U2 snRNP binding

1990 ◽  
Vol 10 (12) ◽  
pp. 6417-6425
Author(s):  
N Abovich ◽  
P Legrain ◽  
M Rosbash
Keyword(s):  
Temperature Sensitive ◽  
Ribonucleoprotein Particle ◽  
Small Nuclear Ribonucleoprotein ◽  
U2 Snrnp ◽  
Snrnp Protein ◽  
Yeast Genes ◽  
Nuclear Ribonucleoprotein ◽  
Small Nuclear Ribonucleoprotein Particle

PRP6 and PRP9 are two yeast genes involved in pre-mRNA splicing. Incubation at 37 degrees C of strains that carry temperature-sensitive mutations at these loci inhibits splicing, and in vivo experiments suggested that they might be involved in commitment complex formation (P. Legrain and M. Rosbash, Cell 57:573-583, 1989). To examine the specific role that the PRP6 and PRP9 products may play in splicing or pre-mRNA transport to the cytoplasm, we have characterized in vitro splicing and spliceosome assembly in extracts derived from prp6 and prp9 mutant strains. We have also characterized RNAs that are specifically immunoprecipitated with the PRP6 and PRP9 proteins. Both approaches indicate that PRP6 encodes a U4/U6 small nuclear ribonucleoprotein particle (snRNP) protein and that the PRP9 protein is required for a stable U2 snRNP-substrate interaction. The results are discussed with reference to the previously observed in vivo phenotypes of these mutants.

PRP4 (RNA4) from Saccharomyces cerevisiae: its gene product is associated with the U4/U6 small nuclear ribonucleoprotein particle

1989 ◽  
Vol 9 (9) ◽  
pp. 3698-3709
Author(s):  
S P Bjørn ◽  
A Soltyk ◽  
J D Beggs ◽  
J D Friesen
Keyword(s):  
Gene Product ◽  
Yeast Cells ◽  
Temperature Sensitive ◽  
Ribonucleoprotein Particle ◽  
Direct Role ◽  
Small Nuclear Ribonucleoprotein ◽  
Cloned Gene ◽  
Nuclear Ribonucleoprotein ◽  
Small Nuclear Ribonucleoprotein Particle

The PRP4 (RNA4) gene product is involved in nuclear mRNA processing in yeast cells; we have previously cloned the gene by complementation of a temperature-sensitive mutation. Sequence and transcript analyses of the cloned gene predicted the gene product to be a 52-kilodalton protein, which was confirmed with antibodies raised against the PRP4 gene product. These antibodies inhibited precursor mRNA splicing in vitro, demonstrating a direct role of PRP4 in splicing. Immunoprecipitations with the antibodies indicated that the PRP4 protein is associated with the U4/U6 small nuclear ribonucleoprotein particle.

scholarly journals PRP4: a protein of the yeast U4/U6 small nuclear ribonucleoprotein particle.

1989 ◽  
Vol 9 (9) ◽  
pp. 3710-3719 ◽  
Author(s):  
J Banroques ◽  
J N Abelson
Keyword(s):  
Essential Role ◽  
Mrna Splicing ◽  
Ribonucleoprotein Particle ◽  
Specific Antibodies ◽  
Small Nuclear Ribonucleoprotein ◽  
Assembly Pathway ◽  
Nuclear Ribonucleoprotein ◽  
Small Nuclear Ribonucleoprotein Particle

The Saccharomyces cerevisiae prp mutants (prp2 through prp11) are known to be defective in pre-mRNA splicing at nonpermissive temperatures. We have sequenced the PRP4 gene and shown that it encodes a 52-kilodalton protein. We obtained PRP4 protein-specific antibodies and found that they inhibited in vitro pre-mRNA splicing, which confirms the essential role of PRP4 in splicing. Moreover, we found that PRP4 is required early in the spliceosome assembly pathway. Immunoprecipitation experiments with anti-PRP4 antibodies were used to demonstrate that PRP4 is a protein of the U4/U6 small nuclear ribonucleoprotein particle (snRNP). Furthermore, the U5 snRNP could be immunoprecipitated through snRNP-snRNP interactions in the large U4/U5/U6 complex.

scholarly journals U1 small nuclear ribonucleoprotein particle-protein interactions are revealed in Saccharomyces cerevisiae by in vivo competition assays.

1993 ◽  
Vol 13 (4) ◽  
pp. 2126-2133 ◽  
Author(s):  
F Stutz ◽  
X C Liao ◽  
M Rosbash
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Growth Rate ◽  
Mammalian Cells ◽  
Wild Type ◽  
Ribonucleoprotein Particle ◽  
Yeast Saccharomyces Cerevisiae ◽  
Small Nuclear Ribonucleoprotein ◽  
U1 Snrna ◽  
Nuclear Ribonucleoprotein ◽  
Small Nuclear Ribonucleoprotein Particle

Two highly conserved regions of the 586-nucleotide yeast (Saccharomyces cerevisiae) U1 small nuclear RNA (snRNA) can be mutated or deleted with little or no effect on growth rate: the universally conserved loop II (corresponding to the metazoan A loop) and the yeast core region (X. Liao, L. Kretzner, B. Séraphin, and M. Rosbash, Genes Dev. 4:1766-1774, 1990). To examine the contribution of these regions to U1 small nuclear ribonucleoprotein particle (snRNP) activity, a competitor U1 gene, encoding a nonfunctional U1 snRNA molecule, was introduced into a number of strains carrying a U1 snRNA gene with loop II or yeast core mutations. The presence of the nonfunctional U1 gene lowered the growth rate of these mutant strains but not wild-type strains, consistent with the notion that mutant U1 RNAs are less active than wild-type U1 snRNAs. A detailed analysis of the U1 snRNA levels and half-lives in a number of merodiploid strains suggests that these mutant U1 snRNAs interact with U1 snRNP proteins less well than do their wild-type counterparts. Competition for protein factors during snRNP assembly could account for a number of previous observations in both yeast and mammalian cells.

U1 small nuclear ribonucleoprotein particle-protein interactions are revealed in Saccharomyces cerevisiae by in vivo competition assays

1993 ◽  
Vol 13 (4) ◽  
pp. 2126-2133
Author(s):  
F Stutz ◽  
X C Liao ◽  
M Rosbash
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Growth Rate ◽  
Mammalian Cells ◽  
Wild Type ◽  
Ribonucleoprotein Particle ◽  
Yeast Saccharomyces Cerevisiae ◽  
Small Nuclear Ribonucleoprotein ◽  
U1 Snrna ◽  
Nuclear Ribonucleoprotein ◽  
Small Nuclear Ribonucleoprotein Particle

Two highly conserved regions of the 586-nucleotide yeast (Saccharomyces cerevisiae) U1 small nuclear RNA (snRNA) can be mutated or deleted with little or no effect on growth rate: the universally conserved loop II (corresponding to the metazoan A loop) and the yeast core region (X. Liao, L. Kretzner, B. Séraphin, and M. Rosbash, Genes Dev. 4:1766-1774, 1990). To examine the contribution of these regions to U1 small nuclear ribonucleoprotein particle (snRNP) activity, a competitor U1 gene, encoding a nonfunctional U1 snRNA molecule, was introduced into a number of strains carrying a U1 snRNA gene with loop II or yeast core mutations. The presence of the nonfunctional U1 gene lowered the growth rate of these mutant strains but not wild-type strains, consistent with the notion that mutant U1 RNAs are less active than wild-type U1 snRNAs. A detailed analysis of the U1 snRNA levels and half-lives in a number of merodiploid strains suggests that these mutant U1 snRNAs interact with U1 snRNP proteins less well than do their wild-type counterparts. Competition for protein factors during snRNP assembly could account for a number of previous observations in both yeast and mammalian cells.

Uncoupling two functions of the U1 small nuclear ribonucleoprotein particle during in vitro splicing

1993 ◽  
Vol 13 (6) ◽  
pp. 3135-3145
Author(s):  
S D Seiwert ◽  
J A Steitz
Keyword(s):  
Splice Site ◽  
Rnase H ◽  
Ribonucleoprotein Particle ◽  
Additional Function ◽  
Small Nuclear Ribonucleoprotein ◽  
U1 Snrna ◽  
In Vitro Splicing ◽  
Nuclear Ribonucleoprotein ◽  
Small Nuclear Ribonucleoprotein Particle

To probe functions of the U1 small nuclear ribonucleoprotein particle (snRNP) during in vitro splicing, we have used unusual splicing substrates which replace the 5' splice site region of an adenovirus substrate with spliced leader (SL) RNA sequences from Leptomonas collosoma or Caenorhabditis elegans. In agreement with previous results (J.P. Bruzik and J.A. Steitz, Cell 62:889-899, 1990), we find that oligonucleotide-targeted RNase H destruction of the 5' end of U1 snRNA inhibits the splicing of a standard adenovirus splicing substrate but not of the SL RNA-containing substrates. However, use of an antisense 2'-O-methyl oligoribonucleotide that disrupts the first stem of U1 snRNA as well as stably sequestering positions of U1 snRNA involved in 5' and 3' splice site recognition inhibits the splicing of both the SL constructs and the standard adenovirus substrate. The 2'-O-methyl oligoribonucleotide is no more effective than RNase H pretreatment in preventing pairing of U1 with the 5' splice site, as assessed by inhibition of psoralen cross-link formation between the SL RNA-containing substrate and U1. The 2'-O-methyl oligoribonucleotide does not alter the protein composition of the U1 monoparticle or deplete the system of essential splicing factors. Native gel analysis indicates that the 2'-O-methyl oligoribonucleotide inhibits splicing by diminishing the formation of splicing complexes. One interpretation of these results is that removal of the 5' end of U1 inhibits base pairing in a different way than sequestering the same sequence with a complementary oligoribonucleotide. Alternatively, our data may indicate that two elements near the 5' end of U1 RNA normally act during spliceosome assembly; the extreme 5' end base pairs with the 5' splice site, while the sequence or structural integrity of stem I is essential for some additional function. It follows that different introns may differ in their use of the repertoire of U1 snRNP functions.

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