scholarly journals Developmental and tissue-specific expression of U4 small nuclear RNA genes.

1988 ◽  
Vol 8 (12) ◽  
pp. 5566-5569 ◽  
Author(s):  
G M Korf ◽  
I W Botros ◽  
W E Stumph
Keyword(s):  
Domestic Chicken ◽  
Sequence Variant ◽  
Small Nuclear Rna ◽  
Specific Expression ◽  
Small Nuclear Rnas ◽  
Specific Manner ◽  
Nuclear Rna ◽  
U4 Rna ◽  
Rna Genes

U4 RNA is one of several small nuclear RNAs involved in the splicing of mRNA precursors. The domestic chicken has two genes per haploid genome that are capable of encoding U4 RNA. The U4X RNA gene (which encodes a sequence variant of U4 RNA that was unknown prior to the cloning of the gene) and the U4B RNA gene were both expressed in vivo in each of seven adult and three embryonic chicken tissues examined. However, the ratio of U4B RNA to U4X RNA can vary more than sevenfold in both a tissue- and stage-specific manner.

Developmental and tissue-specific expression of U4 small nuclear RNA genes

1988 ◽  
Vol 8 (12) ◽  
pp. 5566-5569
Author(s):  
G M Korf ◽  
I W Botros ◽  
W E Stumph
Keyword(s):  
Domestic Chicken ◽  
Sequence Variant ◽  
Small Nuclear Rna ◽  
Specific Expression ◽  
Small Nuclear Rnas ◽  
Specific Manner ◽  
Nuclear Rna ◽  
U4 Rna ◽  
Rna Genes

U4 RNA is one of several small nuclear RNAs involved in the splicing of mRNA precursors. The domestic chicken has two genes per haploid genome that are capable of encoding U4 RNA. The U4X RNA gene (which encodes a sequence variant of U4 RNA that was unknown prior to the cloning of the gene) and the U4B RNA gene were both expressed in vivo in each of seven adult and three embryonic chicken tissues examined. However, the ratio of U4B RNA to U4X RNA can vary more than sevenfold in both a tissue- and stage-specific manner.

scholarly journals U4 small nuclear RNA dissociates from a yeast spliceosome and does not participate in the subsequent splicing reaction.

1991 ◽  
Vol 11 (11) ◽  
pp. 5571-5577 ◽  
Author(s):  
S L Yean ◽  
R J Lin
Keyword(s):  
Mrna Splicing ◽  
Yeast Cells ◽  
Temperature Sensitive ◽  
Small Nuclear Rna ◽  
Small Nuclear Rnas ◽  
Nuclear Rna ◽  
Sensitive Allele ◽  
U4 Rna ◽  
Small Nuclear Ribonucleoproteins

U4 and U6 small nuclear RNAs reside in a single ribonucleoprotein particle, and both are required for pre-mRNA splicing. The U4/U6 and U5 small nuclear ribonucleoproteins join U1 and U2 on the pre-mRNA during spliceosome assembly. Binding of U4 is then destabilized prior to or concomitant with the 5' cleavage-ligation. In order to test the role of U4 RNA, we isolated a functional spliceosome by using extracts prepared from yeast cells carrying a temperature-sensitive allele of prp2 (rna2). The isolated prp2 delta spliceosome contains U2, U5, U6, and possibly also U1 and can be activated to splice the bound pre-mRNA. U4 RNA does not associate with the isolated spliceosomes and is shown not to be involved in the subsequent cleavage-ligation reactions. These results are consistent with the hypothesis that the role of U4 in pre-mRNA splicing is to deliver U6 to the spliceosome.

scholarly journals U4 small nuclear RNA dissociates from a yeast spliceosome and does not participate in the subsequent splicing reaction

1991 ◽  
Vol 11 (11) ◽  
pp. 5571-5577
Author(s):  
S L Yean ◽  
R J Lin
Keyword(s):  
Mrna Splicing ◽  
Yeast Cells ◽  
Temperature Sensitive ◽  
Small Nuclear Rna ◽  
Small Nuclear Rnas ◽  
Nuclear Rna ◽  
Sensitive Allele ◽  
U4 Rna ◽  
Small Nuclear Ribonucleoproteins

U4 and U6 small nuclear RNAs reside in a single ribonucleoprotein particle, and both are required for pre-mRNA splicing. The U4/U6 and U5 small nuclear ribonucleoproteins join U1 and U2 on the pre-mRNA during spliceosome assembly. Binding of U4 is then destabilized prior to or concomitant with the 5' cleavage-ligation. In order to test the role of U4 RNA, we isolated a functional spliceosome by using extracts prepared from yeast cells carrying a temperature-sensitive allele of prp2 (rna2). The isolated prp2 delta spliceosome contains U2, U5, U6, and possibly also U1 and can be activated to splice the bound pre-mRNA. U4 RNA does not associate with the isolated spliceosomes and is shown not to be involved in the subsequent cleavage-ligation reactions. These results are consistent with the hypothesis that the role of U4 in pre-mRNA splicing is to deliver U6 to the spliceosome.

scholarly journals Structural and functional analysis of chicken U4 small nuclear RNA genes.

1986 ◽  
Vol 6 (11) ◽  
pp. 3910-3919 ◽  
Author(s):  
M L Hoffman ◽  
G M Korf ◽  
K J McNamara ◽  
W E Stumph
Keyword(s):  
Distal Region ◽  
Xenopus Laevis Oocytes ◽  
Small Nuclear Rna ◽  
Transcriptional Enhancer ◽  
Base Pairs ◽  
Base Substitutions ◽  
Nuclear Rna ◽  
Sequence Elements ◽  
U4 Rna ◽  
Rna Genes

Two distinct chicken U4 RNA genes have been cloned and characterized. They are closely linked within 465 base pairs of each other and have the same transcriptional orientation. The downstream U4 homology is a true gene, based on the criteria that it is colinear with chicken U4B RNA and is expressed when injected into Xenopus laevis oocytes. The upstream U4 homology, however, contains seven base substitutions relative to U4B RNA. This sequence may be a nonexpressed pseudogene, but the pattern of base substitutions suggests that it more probably encodes a variant yet functional U4 RNA product not yet characterized at the RNA level. In support of this, the two U4 genes have regions of homology with each other in their 5'-flanking DNA at two positions known to be essential for the efficient expression of vertebrate U1 and U2 small nuclear RNA genes. In the case of U1 and U2 RNA genes, the more distal region (located near position-200 with respect to the RNA cap site) is known to function as a transcriptional enhancer. Although this region is highly conserved in overall structure and sequence among U1 and U2 RNA genes, it is much less conserved in the chicken U4 RNA genes reported here. Interestingly, short sequence elements present in the -200 region of the U4 RNA genes are inverted (i.e., on the complementary strand) relative to their usual orientation upstream of U1 and U2 RNA genes. Thus, the -200 region of the U4 RNA genes may represent a natural evolutionary occurrence of an enhancer sequence inversion.

Structural and functional analysis of chicken U4 small nuclear RNA genes

1986 ◽  
Vol 6 (11) ◽  
pp. 3910-3919
Author(s):  
M L Hoffman ◽  
G M Korf ◽  
K J McNamara ◽  
W E Stumph
Keyword(s):  
Distal Region ◽  
Xenopus Laevis Oocytes ◽  
Small Nuclear Rna ◽  
Transcriptional Enhancer ◽  
Base Pairs ◽  
Base Substitutions ◽  
Nuclear Rna ◽  
Sequence Elements ◽  
U4 Rna ◽  
Rna Genes

Two distinct chicken U4 RNA genes have been cloned and characterized. They are closely linked within 465 base pairs of each other and have the same transcriptional orientation. The downstream U4 homology is a true gene, based on the criteria that it is colinear with chicken U4B RNA and is expressed when injected into Xenopus laevis oocytes. The upstream U4 homology, however, contains seven base substitutions relative to U4B RNA. This sequence may be a nonexpressed pseudogene, but the pattern of base substitutions suggests that it more probably encodes a variant yet functional U4 RNA product not yet characterized at the RNA level. In support of this, the two U4 genes have regions of homology with each other in their 5'-flanking DNA at two positions known to be essential for the efficient expression of vertebrate U1 and U2 small nuclear RNA genes. In the case of U1 and U2 RNA genes, the more distal region (located near position-200 with respect to the RNA cap site) is known to function as a transcriptional enhancer. Although this region is highly conserved in overall structure and sequence among U1 and U2 RNA genes, it is much less conserved in the chicken U4 RNA genes reported here. Interestingly, short sequence elements present in the -200 region of the U4 RNA genes are inverted (i.e., on the complementary strand) relative to their usual orientation upstream of U1 and U2 RNA genes. Thus, the -200 region of the U4 RNA genes may represent a natural evolutionary occurrence of an enhancer sequence inversion.

The phylogenetically invariant ACAGAGA and AGC sequences of U6 small nuclear RNA are more tolerant of mutation in human cells than in Saccharomyces cerevisiae

1993 ◽  
Vol 13 (9) ◽  
pp. 5377-5382
Author(s):  
B Datta ◽  
A M Weiner
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transient Expression ◽  
Human Cells ◽  
Mrna Splicing ◽  
Small Nuclear Rna ◽  
Transient Expression Assay ◽  
U6 Snrna ◽  
Nuclear Rna

U6 small nuclear RNA (snRNA) is the most highly conserved of the five spliceosomal snRNAs that participate in nuclear mRNA splicing. The proposal that U6 snRNA plays a key catalytic role in splicing [D. Brow and C. Guthrie, Nature (London) 337:14-15, 1989] is supported by the phylogenetic conservation of U6, the sensitivity of U6 to mutation, cross-linking of U6 to the vicinity of the 5' splice site, and genetic evidence for extensive base pairing between U2 and U6 snRNAs. We chose to mutate the phylogenetically invariant 41-ACAGAGA-47 and 53-AGC-55 sequences of human U6 because certain point mutations within the homologous regions of Saccharomyces cerevisiae U6 selectively block the first or second step of mRNA splicing. We found that both sequences are more tolerant to mutation in human cells (assayed by transient expression in vivo) than in S. cerevisiae (assayed by effects on growth or in vitro splicing). These differences may reflect different rate-limiting steps in the particular assays used or differential reliance on redundant RNA-RNA or RNA-protein interactions. The ability of mutations in U6 nucleotides A-45 and A-53 to selectively block step 2 of splicing in S. cerevisiae had previously been construed as evidence that these residues might participate directly in the second chemical step of splicing; an indirect, structural role seems more likely because the equivalent mutations have no obvious phenotype in the human transient expression assay.

Accumulation of U14 small nuclear RNA in Saccharomyces cerevisiae requires box C, box D, and a 5', 3' terminal stem

1992 ◽  
Vol 12 (10) ◽  
pp. 4456-4463
Author(s):  
G M Huang ◽  
A Jarmolowski ◽  
J C Struck ◽  
M J Fournier
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Binding ◽  
Essential Elements ◽  
Structural Elements ◽  
Small Nuclear Rna ◽  
Small Nuclear Rnas ◽  
Nuclear Rna ◽  
Compensatory Base Changes ◽  
Normal Processing ◽  
Intragenic Suppressor

U14 is one of several nucleolar small nuclear RNAs required for normal processing of rRNA. Functional mapping of U14 from Saccharomyces cerevisiae has yielded a number of mutants defective in U14 accumulation or function. In this study, we have further defined three structural elements required for U14 accumulation. The essential elements include the U14-conserved box C and box D sequences and a 5', 3' terminal stem. The box elements are coconserved among several nucleolar small nuclear RNAs and have been implicated in binding of the protein fibrillarin. New mutational results show that the first GA bases of the box C sequence UGAUGA are essential, and two vital bases in box D have also been identified. An intragenic suppressor of a lethal box C mutant has been isolated and shown to contain a new box C-like PyGAUG sequence two bases upstream of normal box C. The importance of the terminal stem was confirmed from new compensatory base changes and the finding that accumulation defects in the box elements can be complemented by extending the terminal stem. The results suggest that the observed defects in accumulation reflect U14 instability and that protein binding to one or more of these elements is required for metabolic stability.

Varied Transcriptional Efficiencies of Multiple Arabidopsis U6 Small Nuclear RNA Genes

2007 ◽  
Vol 49 (2) ◽  
pp. 222-229 ◽  
Author(s):  
Xia Li ◽  
Dan-Hua Jiang ◽  
Kelan Yong ◽  
Da-Bing Zhang
Keyword(s):  
Small Nuclear Rna ◽  
Nuclear Rna ◽  
Rna Genes
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