scholarly journals Genetic and Functional Interaction of Evolutionarily Conserved Regions of the Prp18 Protein and the U5 snRNA

2005 ◽  
Vol 25 (6) ◽  
pp. 2107-2116 ◽  
Author(s):  
Dagmar Bačíková ◽  
David S. Horowitz
Keyword(s):  
Functional Relationship ◽  
Mrna Splicing ◽  
Second Step ◽  
Functional Interaction ◽  
Synthetic Lethal ◽  
Conserved Regions ◽  
Evolutionarily Conserved ◽  
Conserved Region ◽  
Relationship Of ◽  
U5 Snrna

ABSTRACT Both the Prp18 protein and the U5 snRNA function in the second step of pre-mRNA splicing. We identified suppressors of mutant prp18 alleles in the gene for the U5 snRNA (SNR7). The suppressors' U5 snRNAs have either a U4-to-A or an A8-to-C mutation in the evolutionarily invariant loop 1 of U5. Suppression is specific for prp18 alleles that encode proteins with mutations in a highly conserved region of Prp18 which forms an unstructured loop in crystals of Prp18. The snr7 suppressors partly restored the pre-mRNA splicing activity that was lost in the prp18 mutants. The close functional relationship of Prp18 and U5 is emphasized by the finding that two snr7 alleles, U5A and U6A, are dominant synthetic lethal with prp18 alleles. Our results support the idea that Prp18 and the U5 snRNA act in concert during the second step of pre-mRNA splicing and suggest a model in which the conserved loop of Prp18 acts to stabilize the interaction of loop 1 of the U5 snRNA with the splicing intermediates.

scholarly journals Synthetic lethal mutations suggest interactions between U5 small nuclear RNA and four proteins required for the second step of splicing.

1992 ◽  
Vol 12 (11) ◽  
pp. 5197-5205 ◽  
Author(s):  
D Frank ◽  
B Patterson ◽  
C Guthrie
Keyword(s):  
Mrna Splicing ◽  
Second Step ◽  
Small Nuclear Rna ◽  
Synthetic Lethal ◽  
Lethal Mutations ◽  
Small Nuclear Ribonucleoprotein ◽  
Nuclear Rna ◽  
Nuclear Ribonucleoprotein ◽  
U5 Snrna

To investigate the function of the U5 small nuclear ribonucleoprotein (snRNP) in pre-mRNA splicing, we have screened for factors that genetically interact with Saccharomyces cerevisiae U5 snRNA. We isolated trans-acting mutations that exacerbate the phenotypes of conditional alleles of the U5 snRNA and named these genes SLU, for synergistically lethal with U5 snRNA. SLU1 and SLU2 are essential for the first catalytic step of splicing, while SLU7 and SLU4 (an allele of PRP17 [U. Vijayraghavan, M. Company, and J. Abelson, Genes Dev. 3:1206-1216, 1989]) are required only for the second step of splicing. Furthermore, slu4-1 and slu7-1 are lethal in combination with mutations in PRP16 and PRP18, which also function in the second step, but not with mutations in factors required for the first catalytic step, such as PRP8 and PRP4. We infer from these data that SLU4, SLU7, PRP18, PRP16, and the U5 snRNA interact functionally and that a major role of the U5 snRNP is to coordinate a set of factors that are required for the completion of the second catalytic step of splicing.

Synthetic lethal mutations suggest interactions between U5 small nuclear RNA and four proteins required for the second step of splicing

1992 ◽  
Vol 12 (11) ◽  
pp. 5197-5205
Author(s):  
D Frank ◽  
B Patterson ◽  
C Guthrie
Keyword(s):  
Mrna Splicing ◽  
Second Step ◽  
Small Nuclear Rna ◽  
Synthetic Lethal ◽  
Lethal Mutations ◽  
Small Nuclear Ribonucleoprotein ◽  
Nuclear Rna ◽  
Nuclear Ribonucleoprotein ◽  
U5 Snrna

To investigate the function of the U5 small nuclear ribonucleoprotein (snRNP) in pre-mRNA splicing, we have screened for factors that genetically interact with Saccharomyces cerevisiae U5 snRNA. We isolated trans-acting mutations that exacerbate the phenotypes of conditional alleles of the U5 snRNA and named these genes SLU, for synergistically lethal with U5 snRNA. SLU1 and SLU2 are essential for the first catalytic step of splicing, while SLU7 and SLU4 (an allele of PRP17 [U. Vijayraghavan, M. Company, and J. Abelson, Genes Dev. 3:1206-1216, 1989]) are required only for the second step of splicing. Furthermore, slu4-1 and slu7-1 are lethal in combination with mutations in PRP16 and PRP18, which also function in the second step, but not with mutations in factors required for the first catalytic step, such as PRP8 and PRP4. We infer from these data that SLU4, SLU7, PRP18, PRP16, and the U5 snRNA interact functionally and that a major role of the U5 snRNP is to coordinate a set of factors that are required for the completion of the second catalytic step of splicing.

scholarly journals EB1 and EB3 Control CLIP Dissociation from the Ends of Growing Microtubules

2005 ◽  
Vol 16 (11) ◽  
pp. 5334-5345 ◽  
Author(s):  
Yulia Komarova ◽  
Gideon Lansbergen ◽  
Niels Galjart ◽  
Frank Grosveld ◽  
Gary G. Borisy ◽  
...  
Keyword(s):  
Rna Interference ◽  
Mammalian Cells ◽  
Functional Relationship ◽  
Family Members ◽  
Microtubule Dynamics ◽  
Tyrosine Residue ◽  
Dissociation Kinetics ◽  
Evolutionarily Conserved ◽  
Relationship Of

EBs and CLIPs are evolutionarily conserved proteins, which associate with the tips of growing microtubules, and regulate microtubule dynamics and their interactions with intracellular structures. In this study we investigated the functional relationship of CLIP-170 and CLIP-115 with the three EB family members, EB1, EB2(RP1), and EB3 in mammalian cells. We showed that both CLIPs bind to EB proteins directly. The C-terminal tyrosine residue of EB proteins is important for this interaction. When EB1 and EB3 or all three EBs were significantly depleted using RNA interference, CLIPs accumulated at the MT tips at a reduced level, because CLIP dissociation from the tips was accelerated. Normal CLIP localization was restored by expression of EB1 but not of EB2. An EB1 mutant lacking the C-terminal tail could also fully rescue CLIP dissociation kinetics, but could only partially restore CLIP accumulation at the tips, suggesting that the interaction of CLIPs with the EB tails contributes to CLIP localization. When EB1 was distributed evenly along the microtubules because of overexpression, it slowed down CLIP dissociation but did not abolish its preferential plus-end localization, indicating that CLIPs possess an intrinsic affinity for growing microtubule ends, which is enhanced by an interaction with the EBs.

scholarly journals The Prp18 protein stabilizes the interaction of both exons with the U5 snRNA during the second step of pre-mRNA splicing

2007 ◽  
Vol 21 (10) ◽  
pp. 1204-1216 ◽  
Author(s):  
L. B. Crotti ◽  
D. Bacikova ◽  
D. S. Horowitz
Keyword(s):  
Mrna Splicing ◽  
Second Step ◽  
U5 Snrna

scholarly journals Functional interactions between Prp8, Prp18, Slu7, and U5 snRNA during the second step of pre-mRNA splicing

RNA ◽  
2007 ◽  
Vol 13 (9) ◽  
pp. 1437-1444 ◽  
Author(s):  
A. Aronova ◽  
D. Bacikova ◽  
L. B. Crotti ◽  
D. S. Horowitz ◽  
B. Schwer
Keyword(s):  
Mrna Splicing ◽  
Second Step ◽  
Functional Interactions ◽  
U5 Snrna

Organization of transcription and pre-mRNA splicing within the mammalian cell nucleus

1995 ◽  
Vol 53 ◽  
pp. 768-769
Author(s):  
D.L. Spector ◽  
S. Huang ◽  
S. Kaurin
Keyword(s):  
Rna Polymerase Ii ◽  
Cell Nucleus ◽  
Functional Organization ◽  
Mrna Splicing ◽  
Splicing Factors ◽  
Interchromatin Granule Clusters ◽  
Interchromatin Granule ◽  
Nuclear Regions ◽  
Relationship Of ◽  
Perichromatin Fibrils

We have been interested in the organization of RNA polymerase II transcription and pre-mRNA splicing within the cell nucleus. Several models have been proposed for the functional organization of RNA within the eukaryotic nucleus and for the relationship of this organization to the distribution of pre-mRNA splicing factors. One model suggests that RNAs which must be spliced are capable of recruiting splicing factors to the sites of transcription from storage and/or reassembly sites. When one examines the organization of splicing factors in the nucleus in comparison to the sites of chromatin it is clear that splicing factors are not localized in coincidence with heterochromatin (Fig. 1). Instead, they are distributed in a speckled pattern which is composed of both perichromatin fibrils and interchromatin granule clusters. The perichromatin fibrils are distributed on the periphery of heterochromatin and on the periphery of interchromatin granule clusters as well as being diffusely distributed throughout the nucleoplasm. These nuclear regions have been previously shown to represent initial sites of incorporation of 3H-uridine.

Functional Relationship of Polymerization Sites of Vertebrate Fibrinogens

1979 ◽  
Author(s):  
C Cierniewski ◽  
T Krajewski ◽  
E Janiak
Keyword(s):  
Gel Electrophoresis ◽  
Functional Relationship ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Functional Similarity ◽  
Fractionation Method ◽  
Relationship Of ◽  
Fibrin Monomers ◽  
Fibrinogen Molecule ◽  
Cold Ethanol Fractionation

Various studies on the interaction of immobilized mammalian fibrinogen and fibrin monomers with some fibrinogen derivatives demonstrated the presence of two sets of polymerization sites in the mammalian fibrinogen molecule. We obtained the same results while investigating the fibrinogen molecules of other classes of vertebrates /Pisces. Amphibia. Aves/. Despite significant differences among their subunit structures, all of them contain polymerization sites homologous to mammalian counterparts. Moreover, due to great functional similarity, fibrinogen or fibrin monomers of the analyzed species of Pisces. Amphibia. Aves and Mammalia interacted in a specific way with immobilized pig fibrin monomers or fibrinogen, respectively. Using these pig affinity adsorbents, fibrinogen and fibrin monomers of different vertebrates were isolated directly from plasma and analyzed by SDS polyacrylamide gel electrophoresis. Polypeptide compositions of eluted proteins were identical to those obtained for corresponding fibrinogen preparations isolated by cold-ethanol fractionation method. It appears to indicate that the nature of polymerization sites in vertebrate fibrinogens is alike.

scholarly journals PLRG1 Is an Essential Regulator of Cell Proliferation and Apoptosis during Vertebrate Development and Tissue Homeostasis

2009 ◽  
Vol 29 (11) ◽  
pp. 3173-3185 ◽  
Author(s):  
André Kleinridders ◽  
Hans-Martin Pogoda ◽  
Sigrid Irlenbusch ◽  
Neil Smyth ◽  
Csaba Koncz ◽  
...  
Keyword(s):  
Cell Cycle Progression ◽  
Tissue Homeostasis ◽  
Mrna Splicing ◽  
Vertebrate Development ◽  
Adult Tissue ◽  
Serum Stimulation ◽  
Evolutionarily Conserved ◽  
Proliferation And Apoptosis ◽  
Dependent Cell

ABSTRACT PLRG1, an evolutionarily conserved component of the spliceosome, forms a complex with Pso4/SNEV/Prp19 and the cell division and cycle 5 homolog (CDC5L) that is involved in both pre-mRNA splicing and DNA repair. Here, we show that the inactivation of PLRG1 in mice results in embryonic lethality at 1.5 days postfertilization. Studies of heart- and neuron-specific PLRG1 knockout mice further reveal an essential role of PLRG1 in adult tissue homeostasis and the suppression of apoptosis. PLRG1-deficient mouse embryonic fibroblasts (MEFs) fail to progress through S phase upon serum stimulation and exhibit increased rates of apoptosis. PLRG1 deficiency causes enhanced p53 phosphorylation and stabilization in the presence of increased γ-H2AX immunoreactivity as an indicator of an activated DNA damage response. p53 downregulation rescues lethality in both PLRG1-deficient MEFs and zebrafish in vivo, showing that apoptosis resulting from PLRG1 deficiency is p53 dependent. Moreover, the deletion of PLRG1 results in the relocation of its interaction partner CDC5L from the nucleus to the cytoplasm without general alterations in pre-mRNA splicing. Taken together, the results of this study identify PLRG1 as a critical nuclear regulator of p53-dependent cell cycle progression and apoptosis during both embryonic development and adult tissue homeostasis.

scholarly journals Genetic Interactions WithCLF1Identify Additional Pre-mRNA Splicing Factors and a Link Between Activators of Yeast Vesicular Transport and Splicing

Genetics ◽  
2003 ◽  
Vol 164 (3) ◽  
pp. 895-907 ◽  
Author(s):  
Kevin Vincent ◽  
Qiang Wang ◽  
Steven Jay ◽  
Kathryn Hobbs ◽  
Brian C Rymond
Keyword(s):  
Mrna Splicing ◽  
Splicing Factors ◽  
Sequence Information ◽  
Specific Sequence ◽  
Synthetic Lethal ◽  
Growth Defects ◽  
Mrna Maturation ◽  
Assembly Factor ◽  
Gtpase Activation ◽  
Synthetic Growth

AbstractClf1 is a conserved spliceosome assembly factor composed predominately of TPR repeats. Here we show that the TPR elements are not functionally equivalent, with the amino terminus of Clf1 being especially sensitive to change. Deletion and add-back experiments reveal that the splicing defect associated with TPR removal results from the loss of TPR-specific sequence information. Twelve mutants were found that show synthetic growth defects when combined with an allele that lacks TPR2 (i.e., clf1Δ2). The identified genes encode the Mud2, Ntc20, Prp16, Prp17, Prp19, Prp22, and Syf2 splicing factors and four proteins without established contribution to splicing (Bud13, Cet1, Cwc2, and Rds3). Each synthetic lethal with clf1Δ2 (slc) mutant is splicing defective in a wild-type CLF1 background. In addition to the splicing factors, SSD1, BTS1, and BET4 were identified as dosage suppressors of clf1Δ2 or selected slc mutants. These results support Clf1 function through multiple stages of the spliceosome cycle, identify additional genes that promote cellular mRNA maturation, and reveal a link between Rab/Ras GTPase activation and the process of pre-mRNA splicing.

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