Mammalian nonsense codons can be cis effectors of nuclear mRNA half-life

1994 ◽  
Vol 14 (12) ◽  
pp. 8219-8228
Author(s):  
P Belgrader ◽  
J Cheng ◽  
X Zhou ◽  
L S Stephenson ◽  
L E Maquat
Keyword(s):  
Triosephosphate Isomerase ◽  
Blot Hybridization ◽  
Mrna Level ◽  
Coding Region ◽  
Protein Coding ◽  
Codon Recognition ◽  
Reverse Transcription Pcr ◽  
Nonsense Codon ◽  
Bona Fide ◽  
Nonsense Codons

Frameshift and nonsense mutations within the gene for human triosephosphate isomerase (TPI) that generate a nonsense codon within the first three-fourths of the protein coding region have been found to reduce the abundance of the product mRNA that copurifies with nuclei. The cellular process and location of the nonsense codon-mediated reduction have proven difficult to elucidate for technical reasons. We show here, using electron microscopy to judge the purity of isolated nuclei, that the previously established reduction to 25% of the normal mRNA level is evident for nuclei that are free of detectable cytoplasmic contamination. Therefore, the reduction is likely to be characteristic of bona fide nuclear RNA. Fully spliced nuclear mRNA is identified by Northern (RNA) blot hybridization and a reverse transcription-PCR assay as the species that undergoes decay in experiments that used the human c-fos promoter to elicit a burst and subsequent shutoff of TPI gene transcription upon the addition of serum to serum-deprived cells. Finally, the finding that deletion of a 5' splice site of the TPI gene results predominantly but not exclusively in the removal by splicing (i.e., skipping) of the upstream exon as a part of the flanking introns has been used to demonstrate that decay is specific to those mRNA products that maintain the nonsense codon. This result, together with our previous results that implicate translation by ribosomes and charged tRNAs in the decay mechanism, indicate that nonsense codon recognition takes place after splicing and triggers decay solely in cis. The possibility that decay takes place during the process of mRNA export from the nucleus to the cytoplasm is discussed.

scholarly journals Mammalian nonsense codons can be cis effectors of nuclear mRNA half-life.

1994 ◽  
Vol 14 (12) ◽  
pp. 8219-8228 ◽  
Author(s):  
P Belgrader ◽  
J Cheng ◽  
X Zhou ◽  
L S Stephenson ◽  
L E Maquat
Keyword(s):  
Triosephosphate Isomerase ◽  
Blot Hybridization ◽  
Mrna Level ◽  
Coding Region ◽  
Protein Coding ◽  
Codon Recognition ◽  
Reverse Transcription Pcr ◽  
Nonsense Codon ◽  
Bona Fide ◽  
Nonsense Codons

Frameshift and nonsense mutations within the gene for human triosephosphate isomerase (TPI) that generate a nonsense codon within the first three-fourths of the protein coding region have been found to reduce the abundance of the product mRNA that copurifies with nuclei. The cellular process and location of the nonsense codon-mediated reduction have proven difficult to elucidate for technical reasons. We show here, using electron microscopy to judge the purity of isolated nuclei, that the previously established reduction to 25% of the normal mRNA level is evident for nuclei that are free of detectable cytoplasmic contamination. Therefore, the reduction is likely to be characteristic of bona fide nuclear RNA. Fully spliced nuclear mRNA is identified by Northern (RNA) blot hybridization and a reverse transcription-PCR assay as the species that undergoes decay in experiments that used the human c-fos promoter to elicit a burst and subsequent shutoff of TPI gene transcription upon the addition of serum to serum-deprived cells. Finally, the finding that deletion of a 5' splice site of the TPI gene results predominantly but not exclusively in the removal by splicing (i.e., skipping) of the upstream exon as a part of the flanking introns has been used to demonstrate that decay is specific to those mRNA products that maintain the nonsense codon. This result, together with our previous results that implicate translation by ribosomes and charged tRNAs in the decay mechanism, indicate that nonsense codon recognition takes place after splicing and triggers decay solely in cis. The possibility that decay takes place during the process of mRNA export from the nucleus to the cytoplasm is discussed.

scholarly journals Multilocus Characterization, Gene Expression Analysis of Putative Immunodominant Protein Coding Regions, and Development of Recombinase Polymerase Amplification Assay for Detection of ‘Candidatus Phytoplasma Pruni’ in Prunus avium

2019 ◽  
Vol 109 (6) ◽  
pp. 983-992 ◽  
Author(s):  
Dan Edward V. Villamor ◽  
Kenneth C. Eastwell
Keyword(s):  
High Throughput Sequencing ◽  
Sweet Cherry ◽  
Prunus Avium ◽  
Protein A ◽  
Recombinase Polymerase Amplification ◽  
Sequencing Data ◽  
Coding Region ◽  
Protein Coding ◽  
Coding Regions ◽  
Reverse Transcription Pcr

Western X (WX) disease, caused by ‘Candidatus Phytoplasma pruni’, is a devastating disease of sweet cherry resulting in the production of small, bitter-flavored fruits that are unmarketable. Escalation of WX disease in Washington State prompted the development of a rapid detection assay based on recombinase polymerase amplification (RPA) to facilitate timely removal and replacement of diseased trees. Here, we report on a reliable RPA assay targeting putative immunodominant protein coding regions that showed comparable sensitivity to polymerase chain reaction (PCR) in detecting ‘Ca. Phytoplasma pruni’ from crude sap of sweet cherry tissues. Apart from the predominant strain of ‘Ca. Phytoplasma pruni’, the RPA assay also detected a novel strain of phytoplasma from several WX-affected trees. Multilocus sequence analyses using the immunodominant protein A (idpA), imp, rpoE, secY, and 16S ribosomal RNA regions from several ‘Ca. Phytoplasma pruni’ isolates from WX-affected trees showed that this novel phytoplasma strain represents a new subgroup within the 16SrIII group. Examination of high-throughput sequencing data from total RNA of WX-affected trees revealed that the imp coding region is highly expressed, and as supported by quantitative reverse transcription PCR data, it showed higher RNA transcript levels than the previously proposed idpA coding region of ‘Ca. Phytoplasma pruni’.

scholarly journals Introns are cis effectors of the nonsense-codon-mediated reduction in nuclear mRNA abundance.

1994 ◽  
Vol 14 (9) ◽  
pp. 6317-6325 ◽  
Author(s):  
J Cheng ◽  
P Belgrader ◽  
X Zhou ◽  
L E Maquat
Keyword(s):  
Translation Initiation ◽  
Triosephosphate Isomerase ◽  
Splice Sites ◽  
Nonsense Mutations ◽  
Nonsense Codon ◽  
Exon 1 ◽  
Nonsense Codons ◽  
Intron 2 ◽  
Mediated Reduction ◽  
Downstream Movement

The translation of human triosephosphate isomerase (TPI) mRNA normally terminates at codon 249 within exon 7, the final exon. Frameshift and nonsense mutations of the type that cause translation to terminate prematurely at or upstream of codon 189 within exon 6 reduce the level of nuclear TPI mRNA to 20 to 30% of normal by a mechanism that is not a function of the distance of the nonsense codon from either the translation initiation or termination codon. In contrast, frameshift and nonsense mutations of another type that cause translation to terminate prematurely at or downstream of codon 208, also within exon 6, have no effect on the level of nuclear TPI mRNA. In this work, quantitations of RNA that derived from TPI alleles in which nonsense codons had been generated between codons 189 and 208 revealed that the boundary between the two types of nonsense codons resides between codons 192 and 195. The analysis of TPI gene insertions and deletions indicated that the positional feature differentiating the two types of nonsense codons is the distance of the nonsense codon upstream of intron 6. For example, the movement of intron 6 to a position downstream of its normal location resulted in a concomitant downstream movement of the boundary between the two types of nonsense codons. The analysis of intron 6 mutations indicated that the intron 6 effect is stipulated by the 88 nucleotides residing between the 5' and 3' splice sites. Since the deletion of intron 6 resulted in only partial abrogation of the nonsense codon-mediated reduction in the level of TPI mRNA, other sequences within TPI pre-mRNA must function in the effect. One of these sequences may be intron 2, since the deletion of intron 2 also resulted in partial abrogation of the effect. In experiments that switched introns 2 and 6, the replacement of intron 6 with intron 2 was of no consequence to the effect of a nonsense codon within either exon 1 or exon 6. In contrast, the replacement of intron 2 with intron 6 was inconsequential to the effect of a nonsense codon in exon 6 but resulted in partial abrogation of a nonsense codon in exon 1.

scholarly journals Membrane Adsorption with Direct Cell Culture Combined with Reverse Transcription-PCR as a Fast Method for Identifying Enteroviruses from Sewage

2005 ◽  
Vol 71 (1) ◽  
pp. 72-79 ◽  
Author(s):  
D. Papaventsis ◽  
N. Siafakas ◽  
P. Markoulatos ◽  
G. T. Papageorgiou ◽  
C. Kourtis ◽  
...  
Keyword(s):  
Reverse Transcription ◽  
Sewage Treatment ◽  
Rflp Analysis ◽  
Fast Method ◽  
Coding Region ◽  
Protein Coding ◽  
Membrane Filters ◽  
Reverse Transcription Pcr ◽  
Detection And Identification ◽  
Study Sites

ABSTRACT We present a new approach for the detection and identification of enteroviruses concentrated and isolated from sewage. Samples were collected from two study sites located at Nicosia and Limassol sewage treatment plants in Cyprus. Viruses were adsorbed to cellulose nitrate membrane filters, cultured directly from the membrane filters by using the VIRADEN method, and identified by reverse transcription-PCR, followed by 5′ untranslated region (5′-UTR) restriction fragment length polymorphism (RFLP) analysis and partial sequencing of the VP1 protein coding region. Initial subgrouping based on the HpaII restriction profile showed that all of the isolates except one belonged to the same genetic subcluster. Partial VP1 sequencing revealed that most isolates belonged to serotypes coxsackie B4 (42.5%) and coxsackie Α9 (30%), whereas coxsackie B2 (17.5%) and coxsackie B1 (3%) isolates were less frequently observed. One poliovirus type 2 isolate (2.5%) of vaccine origin was also found. The HpaII digests predicted the genetic subcluster for all isolates. They also accurately differentiated the isolates as nonpolio or polio isolates. This approach seems to be very promising for environmental surveillance of enterovirus circulation and epidemiology, with all of the significant effects that this entails for public health. Partial VP1 sequencing is efficient for molecular serotyping of enteroviruses, while 5′-UTR RFLP analysis with HpaII can also be considered an asset for the initial subclassification of enterovirus isolates.

scholarly journals Infrequent Translation of a Nonsense Codon Is Sufficient to Decrease mRNA Level

1999 ◽  
Vol 10 (3) ◽  
pp. 515-524 ◽  
Author(s):  
Alla Buzina ◽  
Marc J. Shulman
Keyword(s):  
Mammalian Cells ◽  
Translation Termination ◽  
Mrna Level ◽  
Chain Gene ◽  
Nonsense Mutations ◽  
Nonsense Codon ◽  
Residual Level ◽  
Nonsense Codons ◽  
High Level ◽  
In Cis

In many organisms nonsense mutations decrease the level of mRNA. In the case of mammalian cells, it is still controversial whether translation is required for this nonsense-mediated RNA decrease (NMD). Although previous analyzes have shown that conditions that impede translation termination at nonsense codons also prevent NMD, the residual level of termination was unknown in these experiments. Moreover, the conditions used to impede termination might also have interfered with NMD in other ways. Because of these uncertainties, we have tested the effects of limiting translation of a nonsense codon in a different way, using two mutations in the immunoglobulin μ heavy chain gene. For this purpose we exploited an exceptional nonsense mutation at codon 3, which efficiently terminates translation but nonetheless maintains a high level of μ mRNA. We have shown 1) that translation of Ter462 in the double mutant occurs at only ∼4% the normal frequency, and 2) that Ter462 in cis with Ter3 can induce NMD. That is, translation of Ter462 at this low (4%) frequency is sufficient to induce NMD.

scholarly journals Causative Role of Grapevine Red Blotch Virus in Red Blotch Disease

2018 ◽  
Vol 108 (7) ◽  
pp. 902-909 ◽  
Author(s):  
Luz Marcela Yepes ◽  
Elizabeth Cieniewicz ◽  
Björn Krenz ◽  
Heather McLane ◽  
Jeremy R. Thompson ◽  
...  
Keyword(s):  
Rolling Circle Amplification ◽  
Systemic Infection ◽  
Causative Role ◽  
Coding Region ◽  
Protein Coding ◽  
Rolling Circle ◽  
Reverse Transcription Pcr ◽  
Leaf Chlorosis ◽  
The Family

Grapevine red blotch virus (GRBV) has a monopartite single-stranded DNA genome and is the type species of the genus Grablovirus in the family Geminiviridae. To address the etiological role of GRBV in the recently recognized red blotch disease of grapevine, infectious GRBV clones were engineered from the genome of each of the two previously identified phylogenetic clades for Agrobacterium tumefaciens-mediated inoculations of tissue culture-grown Vitis spp. plants. Following agroinoculation and one or two dormancy cycles, systemic GRBV infection was detected by multiplex polymerase chain reaction (PCR) in Vitis vinifera exhibiting foliar disease symptoms but not in asymptomatic vines. Infected rootstock genotype SO4 (V. berlandieri × V. riparia) exhibited leaf chlorosis and cupping, while infection was asymptomatic in agroinoculated 110R (V. berlandieri × V. rupestris), 3309C (V. riparia × V. rupestris), and V. rupestris. Spliced GRBV transcripts of the replicase-associated protein coding region accumulated in leaves of agroinfected vines, as shown by reverse-transcription PCR; this was consistent with systemic infection resulting from virus replication. Additionally, a virus progeny identical in nucleotide sequence to the infectious GRBV clones was recovered from agroinfected vines by rolling circle amplification, cloning, and sequencing. Concomitantly, subjecting naturally infected grapevines to microshoot tip culture resulted in an asymptomatic plant progeny that tested negative for GRBV in multiplex PCR. Altogether, our agroinoculation and therapeutic experiments fulfilled Koch’s postulates and revealed the causative role of GRBV in red blotch disease.

Nonsense codons can reduce the abundance of nuclear mRNA without affecting the abundance of pre-mRNA or the half-life of cytoplasmic mRNA

1993 ◽  
Vol 13 (3) ◽  
pp. 1892-1902 ◽  
Author(s):  
J Cheng ◽  
L E Maquat
Keyword(s):  
Rna Splicing ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Triosephosphate Isomerase ◽  
Detectable Effect ◽  
Nonsense Mutations ◽  
Reading Frame ◽  
Nonsense Codon ◽  
Nonsense Codons ◽  
Mediated Reduction

The abundance of the mRNA for human triosephosphate isomerase (TPI) is decreased to approximately 20% of normal by frameshift and nonsense mutations that cause translation to terminate at a nonsense codon within the first three-fourths of the reading frame. Results of previous studies inhibiting RNA synthesis with actinomycin D suggested that the decrease is not attributable to an increased rate of cytoplasmic mRNA decay. However, the step in TPI RNA metabolism that is altered was not defined, and the use of actinomycin D, in affecting all polymerase II-transcribed genes, could result in artifactual conclusions. In data presented here, the nonsense codon-mediated reduction in the level of TPI mRNA is shown to be characteristic of both nuclear and cytoplasmic fractions of the cell, indicating that the altered metabolic step is nucleus associated. Neither aberrancies in gene transcription nor aberrancies in RNA splicing appear to contribute to the reduction since there were no accompanying changes in the amount of nuclear run-on transcription, the level of any of the six introns in TPI pre-mRNA, or the size of processed mRNA in the nucleus. Deletion of all splice sites that reside downstream of a nonsense codon does not abrogate the reduction, indicating that the reduction takes place independently of the splicing of a downstream intron. Experiments that placed TPI gene expression under the control of the human c-fos promoter, which can be transiently activated by the addition of serum to serum-deprived cells, verified that there is no detectable effect of a nonsense codon on the turnover of cytoplasmic mRNA.

scholarly journals At Least One Intron Is Required for the Nonsense-Mediated Decay of Triosephosphate Isomerase mRNA: a Possible Link between Nuclear Splicing and Cytoplasmic Translation

1998 ◽  
Vol 18 (9) ◽  
pp. 5272-5283 ◽  
Author(s):  
Jing Zhang ◽  
Xiaolei Sun ◽  
Yimei Qian ◽  
Jeffrey P. LaDuca ◽  
Lynne E. Maquat
Keyword(s):  
Translation Initiation ◽  
Mammalian Cells ◽  
Mrna Decay ◽  
Triosephosphate Isomerase ◽  
Translation Termination ◽  
Nonsense Mediated Decay ◽  
Nonsense Codon ◽  
Translation Initiation Codon ◽  
Exon Junctions ◽  
Nonsense Codons

ABSTRACT Mammalian cells have established mechanisms to reduce the abundance of mRNAs that harbor a nonsense codon and prematurely terminate translation. In the case of the human triosephosphate isomerase (TPI gene), nonsense codons located less than 50 to 55 bp upstream of intron 6, the 3′-most intron, fail to mediate mRNA decay. With the aim of understanding the feature(s) of TPI intron 6 that confer function in positioning the boundary between nonsense codons that do and do not mediate decay, the effects of deleting or duplicating introns have been assessed. The results demonstrate that TPI intron 6 functions to position the boundary because it is the 3′-most intron. Since decay takes place after pre-mRNA splicing, it is conceivable that removal of the 3′-most intron from pre-mRNA “marks” the 3′-most exon-exon junction of product mRNA so that only nonsense codons located more than 50 to 55 nucleotides upstream of the “mark” mediate mRNA decay. Decay may be elicited by the failure of translating ribosomes to translate sufficiently close to the mark or, more likely, the scanning or looping out of some component(s) of the translation termination complex to the mark. In support of scanning, a nonsense codon does not elicit decay if some of the introns that normally reside downstream of the nonsense codon are deleted so the nonsense codon is located (i) too far away from a downstream intron, suggesting that all exon-exon junctions may be marked, and (ii) too far away from a downstream failsafe sequence that appears to function on behalf of intron 6, i.e., when intron 6 fails to leave a mark. Notably, the proposed scanning complex may have a greater unwinding capability than the complex that scans for a translation initiation codon since a hairpin structure strong enough to block translation initiation when inserted into the 5′ untranslated region does not block nonsense-mediated decay when inserted into exon 6 between a nonsense codon residing in exon 6 and intron 6.

scholarly journals Nonsense codons can reduce the abundance of nuclear mRNA without affecting the abundance of pre-mRNA or the half-life of cytoplasmic mRNA.

1993 ◽  
Vol 13 (3) ◽  
pp. 1892-1902 ◽  
Author(s):  
J Cheng ◽  
L E Maquat
Keyword(s):  
Rna Splicing ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Triosephosphate Isomerase ◽  
Detectable Effect ◽  
Nonsense Mutations ◽  
Reading Frame ◽  
Nonsense Codon ◽  
Nonsense Codons ◽  
Mediated Reduction

The abundance of the mRNA for human triosephosphate isomerase (TPI) is decreased to approximately 20% of normal by frameshift and nonsense mutations that cause translation to terminate at a nonsense codon within the first three-fourths of the reading frame. Results of previous studies inhibiting RNA synthesis with actinomycin D suggested that the decrease is not attributable to an increased rate of cytoplasmic mRNA decay. However, the step in TPI RNA metabolism that is altered was not defined, and the use of actinomycin D, in affecting all polymerase II-transcribed genes, could result in artifactual conclusions. In data presented here, the nonsense codon-mediated reduction in the level of TPI mRNA is shown to be characteristic of both nuclear and cytoplasmic fractions of the cell, indicating that the altered metabolic step is nucleus associated. Neither aberrancies in gene transcription nor aberrancies in RNA splicing appear to contribute to the reduction since there were no accompanying changes in the amount of nuclear run-on transcription, the level of any of the six introns in TPI pre-mRNA, or the size of processed mRNA in the nucleus. Deletion of all splice sites that reside downstream of a nonsense codon does not abrogate the reduction, indicating that the reduction takes place independently of the splicing of a downstream intron. Experiments that placed TPI gene expression under the control of the human c-fos promoter, which can be transiently activated by the addition of serum to serum-deprived cells, verified that there is no detectable effect of a nonsense codon on the turnover of cytoplasmic mRNA.

Introns are cis effectors of the nonsense-codon-mediated reduction in nuclear mRNA abundance

1994 ◽  
Vol 14 (9) ◽  
pp. 6317-6325
Author(s):  
J Cheng ◽  
P Belgrader ◽  
X Zhou ◽  
L E Maquat
Keyword(s):  
Translation Initiation ◽  
Triosephosphate Isomerase ◽  
Splice Sites ◽  
Nonsense Mutations ◽  
Nonsense Codon ◽  
Exon 1 ◽  
Nonsense Codons ◽  
Intron 2 ◽  
Mediated Reduction ◽  
Downstream Movement

The translation of human triosephosphate isomerase (TPI) mRNA normally terminates at codon 249 within exon 7, the final exon. Frameshift and nonsense mutations of the type that cause translation to terminate prematurely at or upstream of codon 189 within exon 6 reduce the level of nuclear TPI mRNA to 20 to 30% of normal by a mechanism that is not a function of the distance of the nonsense codon from either the translation initiation or termination codon. In contrast, frameshift and nonsense mutations of another type that cause translation to terminate prematurely at or downstream of codon 208, also within exon 6, have no effect on the level of nuclear TPI mRNA. In this work, quantitations of RNA that derived from TPI alleles in which nonsense codons had been generated between codons 189 and 208 revealed that the boundary between the two types of nonsense codons resides between codons 192 and 195. The analysis of TPI gene insertions and deletions indicated that the positional feature differentiating the two types of nonsense codons is the distance of the nonsense codon upstream of intron 6. For example, the movement of intron 6 to a position downstream of its normal location resulted in a concomitant downstream movement of the boundary between the two types of nonsense codons. The analysis of intron 6 mutations indicated that the intron 6 effect is stipulated by the 88 nucleotides residing between the 5' and 3' splice sites. Since the deletion of intron 6 resulted in only partial abrogation of the nonsense codon-mediated reduction in the level of TPI mRNA, other sequences within TPI pre-mRNA must function in the effect. One of these sequences may be intron 2, since the deletion of intron 2 also resulted in partial abrogation of the effect. In experiments that switched introns 2 and 6, the replacement of intron 6 with intron 2 was of no consequence to the effect of a nonsense codon within either exon 1 or exon 6. In contrast, the replacement of intron 2 with intron 6 was inconsequential to the effect of a nonsense codon in exon 6 but resulted in partial abrogation of a nonsense codon in exon 1.

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