scholarly journals Point mutations in the stem-loop at the 3' end of mouse histone mRNA reduce expression by reducing the efficiency of 3' end formation.

1994 ◽  
Vol 14 (3) ◽  
pp. 1709-1720 ◽  
Author(s):  
N B Pandey ◽  
A S Williams ◽  
J H Sun ◽  
V D Brown ◽  
U Bond ◽  
...  
Keyword(s):  
Base Pair ◽  
Point Mutations ◽  
Histone Mrna ◽  
Base Pairs ◽  
Stem Loop ◽  
Histone Mrnas ◽  
Loop Sequence ◽  
Processing Signal

Mammalian histone mRNAs end in a highly conserved stem-loop structure, with a six-base stem and a four-base loop. We have examined the effect of mutating the stem-loop on the expression of the histone mRNA in vivo by introducing the mutated histone genes into CHO cells by stable transfection. Point mutations have been introduced into the loop sequence and into the UA base pair at the top of the stem. Changing either the first or the third base of the conserved UYUN sequence in the loop to a purine greatly reduced expression, while changing both U's to purines abolished expression. A number of alterations in the stem sequence, including reversing the stem sequence, reversing the two base pairs at the base of the stem, or destroying the UA base pair at the top of the stem, also abolished expression. Changing the UA base pair to a CG or a UG base pair also reduced expression. The loss of expression is due to inefficient processing of the pre-mRNA, as judged by the efficiency of processing in vitro. Addition of a polyadenylation site or the wild-type histone processing signal downstream of a mutant stem-loop resulted in rescuing the processing of the mutant pre-histone mRNA. These results suggest that if the histone pre-mRNA is not rapidly processed, then it is degraded.

scholarly journals Point mutations in the stem-loop at the 3' end of mouse histone mRNA reduce expression by reducing the efficiency of 3' end formation

1994 ◽  
Vol 14 (3) ◽  
pp. 1709-1720
Author(s):  
N B Pandey ◽  
A S Williams ◽  
J H Sun ◽  
V D Brown ◽  
U Bond ◽  
...  
Keyword(s):  
Base Pair ◽  
Point Mutations ◽  
Histone Mrna ◽  
Base Pairs ◽  
Stem Loop ◽  
Histone Mrnas ◽  
Loop Sequence ◽  
Processing Signal

Mammalian histone mRNAs end in a highly conserved stem-loop structure, with a six-base stem and a four-base loop. We have examined the effect of mutating the stem-loop on the expression of the histone mRNA in vivo by introducing the mutated histone genes into CHO cells by stable transfection. Point mutations have been introduced into the loop sequence and into the UA base pair at the top of the stem. Changing either the first or the third base of the conserved UYUN sequence in the loop to a purine greatly reduced expression, while changing both U's to purines abolished expression. A number of alterations in the stem sequence, including reversing the stem sequence, reversing the two base pairs at the base of the stem, or destroying the UA base pair at the top of the stem, also abolished expression. Changing the UA base pair to a CG or a UG base pair also reduced expression. The loss of expression is due to inefficient processing of the pre-mRNA, as judged by the efficiency of processing in vitro. Addition of a polyadenylation site or the wild-type histone processing signal downstream of a mutant stem-loop resulted in rescuing the processing of the mutant pre-histone mRNA. These results suggest that if the histone pre-mRNA is not rapidly processed, then it is degraded.

scholarly journals Two Xenopus Proteins That Bind the 3′ End of Histone mRNA: Implications for Translational Control of Histone Synthesis during Oogenesis

1999 ◽  
Vol 19 (1) ◽  
pp. 835-845 ◽  
Author(s):  
Zeng-Feng Wang ◽  
Thomas C. Ingledue ◽  
Zbigniew Dominski ◽  
Ricardo Sanchez ◽  
William F. Marzluff
Keyword(s):  
Translational Control ◽  
Mrna Processing ◽  
Loop Structure ◽  
Histone Mrna ◽  
Stem Loop ◽  
Histone Mrnas ◽  
Stem Loop Structure ◽  
Histone Synthesis

ABSTRACT Translationally inactive histone mRNA is stored in frog oocytes, and translation is activated at oocyte maturation. The replication-dependent histone mRNAs are not polyadenylated and end in a conserved stem-loop structure. There are two proteins (SLBPs) which bind the 3′ end of histone mRNA in frog oocytes. SLBP1 participates in pre-mRNA processing in the nucleus. SLBP2 is oocyte specific, is present in the cytoplasm, and does not support pre-mRNA processing in vivo or in vitro. The stored histone mRNA is bound to SLBP2. As oocytes mature, SLBP2 is degraded and a larger fraction of the histone mRNA is bound to SLBP1. The mechanism of activation of translation of histone mRNAs may involve exchange of SLBPs associated with the 3′ end of histone mRNA.

scholarly journals The Stem-Loop Binding Protein Is Required for Efficient Translation of Histone mRNA In Vivo and In Vitro

2002 ◽  
Vol 22 (20) ◽  
pp. 7093-7104 ◽  
Author(s):  
Ricardo Sànchez ◽  
William F. Marzluff
Keyword(s):  
Small Region ◽  
Histone Mrna ◽  
Single Class ◽  
Stem Loop ◽  
Histone Mrnas ◽  
Reticulocyte Lysate ◽  
Luciferase Mrna ◽  
Reporter Mrna

ABSTRACT Metazoan replication-dependent histone mRNAs end in a conserved stem-loop rather than in the poly(A) tail found on all other mRNAs. The 3′ end of histone mRNA binds a single class of proteins, the stem-loop binding proteins (SLBP). In Xenopus, there are two SLBPs: xSLBP1, the homologue of the mammalian SLBP, which is required for processing of histone pre-mRNA, and xSLBP2, which is expressed only during oogenesis and is bound to the stored histone mRNA in Xenopus oocytes. The stem-loop is required for efficient translation of histone mRNAs and substitutes for the poly(A) tail, which is required for efficient translation of other eucaryotic mRNAs. When a rabbit reticulocyte lysate is programmed with uncapped luciferase mRNA ending in the histone stem-loop, there is a three- to sixfold increase in translation in the presence of xSLBP1 while xSLBP2 has no effect on translation. Neither SLBP affected the translation of a luciferase mRNA ending in a mutant stem-loop that does not bind SLBP. Capped luciferase mRNAs ending in the stem-loop were injected into Xenopus oocytes after overexpression of either xSLBP1 or xSLBP2. Overexpression of xSLBP1 in the oocytes stimulated translation, while overexpression of xSLBP2 reduced translation of the luciferase mRNA ending in the histone stem-loop. A small region in the N-terminal portion of xSLBP1 is required to stimulate translation both in vivo and in vitro. An MS2-human SLBP1 fusion protein can activate translation of a reporter mRNA ending in an MS2 binding site, indicating that xSLBP1 only needs to be recruited to the 3′ end of the mRNA but does not need to be directly bound to the histone stem-loop to activate translation.

scholarly journals Sequences that regulate the divergent GAL1-GAL10 promoter in Saccharomyces cerevisiae.

1984 ◽  
Vol 4 (8) ◽  
pp. 1440-1448 ◽  
Author(s):  
M Johnston ◽  
R W Davis
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Nucleotide Sequence ◽  
Base Pair ◽  
Transcription Initiation ◽  
Base Pairs ◽  
Regulation Of Expression ◽  
Notable Feature ◽  
His3 Gene

The GAL1 and GAL10 genes of Saccharomyces cerevisiae are divergently transcribed, with 606 base pairs of DNA separating their transcription initiation sites. These two genes are stringently coregulated: their expression is induced ca. 1,000-fold in cells growing on galactose and is repressed by growth on glucose. The nucleotide sequence of the region of DNA between these genes and the precise sites of transcription initiation are presented here. The most notable feature of the nucleotide sequence of this region is a 108-base-pair guanine-plus-cytosine-rich stretch of DNA located approximately in the middle of the region between GAL1 and GAL10. Analysis of the effects of mutations that alter the region between these two genes, constructed in vitro or selected in vivo, suggest that these guanine-plus-cytosine-rich sequences are required for the expression of both genes. The region of DNA between GAL1 and GAL10 is sufficient for regulation of expression of these genes: fusion of the region to the yeast HIS3 gene places HIS3 under GAL control.

scholarly journals Significance in Replication of the Terminal Nucleotides of the Flavivirus Genome

2003 ◽  
Vol 77 (19) ◽  
pp. 10623-10629 ◽  
Author(s):  
Alexander A Khromykh ◽  
Natasha Kondratieva ◽  
Jean-Yves Sgro ◽  
Ann Palmenberg ◽  
Edwin G Westaway
Keyword(s):  
Rna Synthesis ◽  
Point Mutations ◽  
In Vitro Activity ◽  
Rna Dependent Rna Polymerase ◽  
Stem Loop ◽  
Double Stranded Rna ◽  
Positive Strand ◽  
Proposed Model

ABSTRACT Point mutations that resulted in a substitution of the conserved 3′-penultimate cytidine in genomic RNA or the RNA negative strand of the self-amplifying replicon of the Flavivirus Kunjin virus completely blocked in vivo replication. Similarly, substitutions of the conserved 3′-terminal uridine in the RNA negative or positive strand completely blocked replication or caused much-reduced replication, respectively. The same preference for cytidine in the 3′-terminal dinucleotide was noted in reports of the in vitro activity of the RNA-dependent RNA polymerase (RdRp) for the other genera of Flaviviridae that also employ a double-stranded RNA (dsRNA) template to initiate asymmetric semiconservative RNA positive-strand synthesis. The Kunjin virus replicon results were interpreted in the context of a proposed model for initiation of RNA synthesis based on the solved crystal structure of the RdRp of φ6 bacteriophage, which also replicates efficiently using a dsRNA template with conserved 3′-penultimate cytidines and a 3′-terminal pyrimidine. A previously untested substitution of the conserved pentanucleotide at the top of the 3′-terminal stem-loop of all Flavivirus species also blocked detectable in vivo replication of the Kunjin virus replicon RNA.

Sequences that regulate the divergent GAL1-GAL10 promoter in Saccharomyces cerevisiae

1984 ◽  
Vol 4 (8) ◽  
pp. 1440-1448
Author(s):  
M Johnston ◽  
R W Davis
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Nucleotide Sequence ◽  
Base Pair ◽  
Transcription Initiation ◽  
Base Pairs ◽  
Regulation Of Expression ◽  
Notable Feature ◽  
His3 Gene

The GAL1 and GAL10 genes of Saccharomyces cerevisiae are divergently transcribed, with 606 base pairs of DNA separating their transcription initiation sites. These two genes are stringently coregulated: their expression is induced ca. 1,000-fold in cells growing on galactose and is repressed by growth on glucose. The nucleotide sequence of the region of DNA between these genes and the precise sites of transcription initiation are presented here. The most notable feature of the nucleotide sequence of this region is a 108-base-pair guanine-plus-cytosine-rich stretch of DNA located approximately in the middle of the region between GAL1 and GAL10. Analysis of the effects of mutations that alter the region between these two genes, constructed in vitro or selected in vivo, suggest that these guanine-plus-cytosine-rich sequences are required for the expression of both genes. The region of DNA between GAL1 and GAL10 is sufficient for regulation of expression of these genes: fusion of the region to the yeast HIS3 gene places HIS3 under GAL control.

scholarly journals A Novel Upstream RNA Polymerase III Promoter Element Becomes Essential When the Chromatin Structure of the Yeast U6 RNA Gene Is Altered

2001 ◽  
Vol 21 (19) ◽  
pp. 6429-6439 ◽  
Author(s):  
Michael P. Martin ◽  
Valerie L. Gerlach ◽  
David A. Brow
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Iii ◽  
Point Mutations ◽  
Tata Box ◽  
Initiation Factor ◽  
Base Pairs ◽  
Polymerase Iii ◽  
U6 Rna

ABSTRACT The Saccharomyces cerevisiae U6 RNA gene,SNR6, possesses upstream sequences that allow productive binding in vitro of the RNA polymerase III (Pol III) transcription initiation factor IIIB (TFIIIB) in the absence of TFIIIC or other assembly factors. TFIIIC-independent transcription ofSNR6 in vitro is highly sensitive to point mutations in a consensus TATA box at position −30. In contrast, the TATA box is dispensable for SNR6 transcription in vivo, apparently because TFIIIC bound to the intragenic A block and downstream B block can recruit TFIIIB via protein-protein interactions. A mutant allele ofSNR6 with decreased spacing between the A and B blocks,snr6-Δ42, exhibits increased dependence on the upstream sequences in vivo. Unexpectedly, we find that in vivo expression of snr6-Δ42 is much more sensitive to mutations in a (dT-dA)7 tract between the TATA box and transcription start site than to mutations in the TATA box itself. Inversion of single base pairs in the center of the dT-dA tract nearly abolishes transcription of snr6-Δ42, yet inversion of all 7 base pairs has little effect on expression, indicating that the dA-dT tract is relatively orientation independent. Although it is within the TFIIIB footprint, point mutations in the dT-dA tract do not inhibit TFIIIB binding or TFIIIC-independent transcription ofSNR6 in vitro. In the absence of the chromatin architectural protein Nhp6, dT-dA tract mutations are lethal even when A-to-B block spacing is wild type. We conclude that the (dT-dA)7 tract and Nhp6 cooperate to direct productive transcription complex assembly on SNR6 in vivo.

scholarly journals Drosophila Stem-Loop Binding Protein Intracellular Localization Is Mediated by Phosphorylation and Is Required for Cell Cycle-regulated Histone mRNA Expression

2004 ◽  
Vol 15 (3) ◽  
pp. 1112-1123 ◽  
Author(s):  
David J. Lanzotti ◽  
Jeremy M. Kupsco ◽  
Xiao-Cui Yang ◽  
Zbigniew Dominski ◽  
William F. Marzluff ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Rna Binding ◽  
Binding Protein ◽  
Intracellular Localization ◽  
Mrna Processing ◽  
Nuclear Targeting ◽  
Histone Mrna ◽  
Stem Loop

Stem-loop binding protein (SLBP) is an essential component of the histone pre-mRNA processing machinery. SLBP protein expression was examined during Drosophila development by using transgenes expressing hemagglutinin (HA) epitope-tagged proteins expressed from the endogenous Slbp promoter. Full-length HA-dSLBP complemented a Slbp null mutation, demonstrating that it was fully functional. dSLBP protein accumulates throughout the cell cycle, in contrast to the observed restriction of mammalian SLBP to S phase. dSLBP is located in both nucleus and cytoplasm in replicating cells, but it becomes predominantly nuclear during G2. dSLBP is present in mitotic cells and is down-regulated in G1 when cells exit the cell cycle. We determined whether mutation at previously identified phosphorylation sites, T120 and T230, affected the ability of the protein to restore viability and histone mRNA processing to dSLBP null mutants. The T120A SLBP restored viability and histone pre-mRNA processing. However, the T230A mutant, located in a conserved TPNK sequence in the RNA binding domain, did not restore viability and histone mRNA processing in vivo, although it had full activity in histone mRNA processing in vitro. The T230A protein is concentrated in the cytoplasm, suggesting that it is defective in nuclear targeting, and accounting for its failure to function in histone pre-mRNA processing in vivo.

scholarly journals Simian virus 40 major late promoter: a novel tripartite structure that includes intragenic sequences.

1988 ◽  
Vol 8 (5) ◽  
pp. 2021-2033 ◽  
Author(s):  
D E Ayer ◽  
W S Dynan
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Point Mutations ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
Transcription Unit ◽  
Tata Box ◽  
Base Pairs

Unlike most genes transcribed by RNA polymerase II, the simian virus 40 late transcription unit does not have a TATA box. To determine what sequences are required for initiation at the major late mRNA cap site of simian virus 40, clustered point mutations were constructed and tested for transcriptional activity in vitro and in vivo. Three promoter elements were defined. The first is centered 31 base pairs upstream of the cap site in a position normally reserved for a TATA box. The second is at the cap site. The third occupies a novel position centered 28 base pairs downstream of the cap site within a protein-coding sequence. The ability of RNA polymerase II to recognize this promoter suggests that there is greater variation in promoter architecture than had been believed previously.

scholarly journals Studies of point mutants define three essential paired nucleotides in the domain 5 substructure of a group II intron.

1995 ◽  
Vol 15 (8) ◽  
pp. 4479-4488 ◽  
Author(s):  
S C Boulanger ◽  
S M Belcher ◽  
U Schmidt ◽  
S D Dib-Hajj ◽  
T Schmidt ◽  
...  
Keyword(s):  
Point Mutations ◽  
Group Ii Intron ◽  
The Other ◽  
Base Pairs ◽  
Saccharomyces Cerevisiae Mitochondria ◽  
Small Nuclear Rnas ◽  
Group Ii ◽  
Self Splicing

Domain 5 (D5) is a highly conserved, largely helical substructure of group II introns that is essential for self-splicing. Only three of the 14 base pairs present in most D5 structures (A2.U33, G3.U32, and C4.G31) are nearly invariant. We have studied effects of point mutations of those six nucleotides on self-splicing and in vivo splicing of aI5 gamma, an intron of the COXI gene of Saccharomyces cerevisiae mitochondria. Though none of the point mutations blocked self-splicing under one commonly used in vitro reaction condition, the most debilitating mutations were at G3 and G4. Following mitochondrial Biolistic transformation, it was found that mutations at A2, G3, and C4 blocked respiratory growth and splicing while mutations at the other sites had little effect on either phenotype. Intra-D5 second-site suppressors showed that pairing between nucleotides at positions 2 and 33 and 4 and 31 is especially important for D5 function. At the G3.U32 wobble pair, the mutant A.U pair blocks splicing, but a revertant of that mutant that can form an A+.C base pair regains some splicing. A dominant nuclear suppressor restores some splicing to the G3A mutant but not the G3U mutant, suggesting that a purine is required at position 3. These findings are discussed in terms of the hypothesis of Madhani and Guthrie (H. D. Madhani and C. Guthrie, Cell 71:803-817, 1992) that helix 1 formed between yeast U2 and U6 small nuclear RNAs may be the spliceosomal cognate of D5.

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