Autocatalytic activities of intron 5 of the cob gene of yeast mitochondria

1988 ◽  
Vol 8 (6) ◽  
pp. 2562-2571
Author(s):  
S Partono ◽  
A S Lewin
Keyword(s):  
Group I Introns ◽  
Yeast Mitochondria ◽  
High Concentration ◽  
Functional Protein ◽  
Full Spectrum ◽  
Group I ◽  
Intron Boundary ◽  
Monovalent Ion

The terminal intron of the mitochondrial cob gene of Saccharomyces cerevisiae can undergo autocatalytic splicing in vitro. Efficient splicing of this intron required a high concentration of monovalent ion (1 M). We found that at a high salt concentration this intron was very active and performed many of the reactions described for other group I introns. The rate of the splicing reaction was dependent on the choice of the monovalent ion; the reaction intermediate, the intron-3' exon molecule, accumulated in NH4Cl but not in KCl. In addition, the intron was more reactive in KCl, accumulating in two different circular forms: one cyclized at the 5' intron boundary and the other at 236 nucleotides from the 5' end. These circular forms were able to undergo the opening and recyclization reactions previously described for the Tetrahymena rRNA intron. Cleavage of the 5' exon-intron boundary by the addition of GTP did not require the 3' terminus of the intron and the downstream exon. An anomalous guanosine addition at the 3' exon and at the middle of the intron was also detected. Hence, this intron, which requires a functional protein to splice in vivo, demonstrated a full spectrum of characteristic reactions in the absence of proteins.

A Novel Mutation of ADAMTS13 Gene in Congenital Thrombotic Thrombocytopenic Purpura

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4674-4674
Author(s):  
Xia Bai ◽  
Jian Su ◽  
Minghua Jiang ◽  
Zhaoyue Wang ◽  
Changgeng Ruan
Keyword(s):  
Conflicts Of Interest ◽  
Novel Mutation ◽  
Gene Mutations ◽  
Type I ◽  
Adamts13 Activity ◽  
Intron Boundary ◽  
Congenital Thrombotic Thrombocytopenic Purpura ◽  
Peripheral Leukocytes ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract Abstract 4674 Congenital thrombotic thrombocytopenic purura (TTP) is caused by gene mutations of von Willebrand factor-cleaving protease (a disintegrin and metalloprotease with thrombospondin type I domains 13, ADAMTS13). In this study, one novel mutation in the ADAMTS13 gene was found in a woman whose presents are first cousins. Thrombocytopenia occurred during the second trimesters in her first pregnancy, and she died of recurrent attacks after diagnosis of TTP. The ADAMTS13 activity measured using the recombinant FRET-VWF73 during her acute episode was less than 5%. ADAMTS13 inhibitor was negative measured by 9:1 mixture of patient and pooled normal plasma followed by ADAMTS13 activity assay using the VWF multimer electrophoresis. The 29 exons and exon-intron boundary sites of ADAMTS13 gene was analyzed using the human genomic DNA extracted from peripheral leukocytes of the patient. The results demonstrated she was homozygous for R498C. This novel mutant was constructed using the expression plasmid pSectag containing ADAMTS13 cDNA, and the vector was introduced by linpofectamine 2000 to Hela cells. Western Blot revealed that rADAMTS13-wide type (WT) was synthesized as a single band with molecular mass close to 190 Kda in the conditioned media, however, no detectable ADAMTS13 of this mutant existed. The lysates of cells expressing the mutant showed the same protein amounts compared to the rADAMTS13-WT. The immunofluorescence study demonstrated that mutant had the same localization pattern at Endoplasmic Reticulum(ER)and Golgi-compartments compared to the rADAMTS13-WT. The results imply that this mutant may be retained in the cellular ER and Golgi-comparments, but rapidly degraded or insufficiently secreted. Disclosures: No relevant conflicts of interest to declare.

Comparison of transfer RNA and ribosomal RNA intron splicing in the extreme thermophile and archaebacterium Desulfurococcus mobilis

1989 ◽  
Vol 35 (1) ◽  
pp. 210-214 ◽  
Author(s):  
Jørgen Kjems ◽  
Jonna Jensen ◽  
Tina Olesen ◽  
Roger A. Garrett
Keyword(s):  
Structural Feature ◽  
Ribosomal Rna ◽  
Structural Features ◽  
Intron Evolution ◽  
Extreme Thermophile ◽  
Cleavage Process ◽  
Cleavage Enzyme ◽  
Intron Boundary ◽  
23S Ribosomal Rna ◽  
Common Structural Feature

The structure of the exon–intron boundary was compared for an intron within 23S ribosomal RNA of Desulfurococcus mobilis and a newly discovered intron in tRNAMet from the same organism. The occurrence of a putative common structural feature suggests that intron excision occurs by the same mechanism. The possible recognition of this structural feature by the cleavage enzyme was investigated for the ribosomal RNA intron using RNA substrates exhibiting various exon and intron deletions. The results support the involvement of the structural features in the cleavage process. The evolutionary implications of these results are considered.Key words: archaebacteria, tRNA, ribosomal RNA, introns, intron evolution.

A 96-well formatted method for exon and exon/intron boundary full sequencing of the CFTR gene

2006 ◽  
Vol 353 (2) ◽  
pp. 226-235 ◽  
Author(s):  
Marco Lucarelli ◽  
Lorena Narzi ◽  
Rita Piergentili ◽  
Giampiero Ferraguti ◽  
Francesco Grandoni ◽  
...  
Keyword(s):  
Cftr Gene ◽  
Intron Boundary

scholarly journals Hyperinsulinism/hyperammonemia (HI/HA) syndrome due to a mutation in the glutamate dehydrogenase gene

2012 ◽  
Vol 56 (8) ◽  
pp. 485-489 ◽  
Author(s):  
Maria Lúcia Corrêa-Giannella ◽  
Daniel Soares Freire ◽  
Ana Mercedes Cavaleiro ◽  
Maria Angela Zanella Fortes ◽  
Ricardo Rodrigues Giorgi ◽  
...  
Keyword(s):  
Glutamate Dehydrogenase ◽  
De Novo ◽  
Direct Sequencing ◽  
Elevated Serum ◽  
Patient Treatment ◽  
Hyperinsulinemic Hypoglycemia ◽  
Activating Mutations ◽  
Dominant Disease ◽  
Intron Boundary ◽  
Fasting Hypoglycemia

The hyperinsulinism/hyperammonemia (HI/HA) syndrome is a rare autosomal dominant disease manifested by hypoglycemic symptoms triggered by fasting or high-protein meals, and by elevated serum ammonia. HI/HA is the second most common cause of hyperinsulinemic hypoglycemia of infancy, and it is caused by activating mutations in GLUD1, the gene that encodes mitochondrial enzyme glutamate dehydrogenase (GDH). Biochemical evaluation, as well as direct sequencing of exons and exon-intron boundary regions of the GLUD1 gene, were performed in a 6-year old female patient presenting fasting hypoglycemia and hyperammonemia. The patient was found to be heterozygous for one de novo missense mutation (c.1491A>G; p.Il497Met) previously reported in a Japanese patient. Treatment with diazoxide 100 mg/day promoted complete resolution of the hypoglycemic episodes. Arq Bras Endocrinol Metab. 2012;56(8):485-9

scholarly journals Storing memories: the distinct phases of Polycomb-mediated silencing of Arabidopsis FLC

2019 ◽  
Vol 47 (4) ◽  
pp. 1187-1196 ◽  
Author(s):  
Silvia Costa ◽  
Caroline Dean
Keyword(s):  
Target Genes ◽  
Epigenetic Silencing ◽  
Epigenetic Switch ◽  
Cold Temperatures ◽  
Polycomb Repressive Complex 2 ◽  
Sequence Of Events ◽  
Evolutionarily Conserved ◽  
Intron Boundary ◽  
Polycomb Complex

Abstract Polycomb-mediated epigenetic silencing is central to correct growth and development in higher eukaryotes. The evolutionarily conserved Polycomb repressive complex 2 (PRC2) transcriptionally silences target genes through a mechanism requiring the histone modification H3K27me3. However, we still do not fully understand what defines Polycomb targets, how their expression state is switched from epigenetically ON to OFF and how silencing is subsequently maintained through many cell divisions. An excellent system in which to dissect the sequence of events underlying an epigenetic switch is the Arabidopsis FLC locus. Exposure to cold temperatures progressively induces a PRC2-dependent switch in an increasing proportion of cells, through a mechanism that is driven by the local chromatin environment. Temporally distinct phases of this silencing mechanism have been identified. First, the locus is transcriptionally silenced in a process involving cold-induced antisense transcripts; second, nucleation at the first exon/intron boundary of a Polycomb complex containing cold-induced accessory proteins induces a metastable epigenetically silenced state; third, a Polycomb complex with a distinct composition spreads across the locus in a process requiring DNA replication to deliver long-term epigenetic silencing. Detailed understanding from this system is likely to provide mechanistic insights important for epigenetic silencing in eukaryotes generally.

scholarly journals Molecular basis of RhD-positive/D-negative chimerism in two patients

2004 ◽  
Vol 10 (1-2) ◽  
pp. 228-241
Author(s):  
S. S. Eid
Keyword(s):  
Molecular Basis ◽  
Genomic Dna ◽  
Major Change ◽  
Base Change ◽  
Cell Populations ◽  
Rt Pcr ◽  
Single Base ◽  
Intron Boundary ◽  
Single Base Change ◽  
Exon 9

This study investigated two patients with Rh chimerism:patient A, a healthy individual, and patient B with myelofibrosis. Flow cytometry studies showed two red blood cell populations of Rh phenotypes R1r and rr at percentages of about 25% and 75% respectively. Normal RhD transcript sequences were found following RT-PCR. Genomic DNA [gDNA] showed normal exon, intron, GATA regions and exon/intron boundary sequences except for a single base change in intron 7 [C –>A] of exon 7 in patient A. The major change found in both patients was the absence of RHD exon 9 DNA in gDNA isolated from peripheral blood. These findings suggest a somatic mutation, probably in a stem cell common to the myeloid lineage of both patients, and indicate that patient A may undergo malignant transformation in the future

scholarly journals Mutational Analysis of EXT1in a Chinese Family Affected by Hereditary Multiple Osteochondroma

2021 ◽  
Vol 2021 ◽  
pp. 1-5
Author(s):  
Guangzhi Yuan ◽  
Qiang Su ◽  
Wenjun Liao ◽  
Wei Hou ◽  
Linke Huang ◽  
...  
Keyword(s):  
Mutational Analysis ◽  
Pathogenic Mutation ◽  
Chinese Family ◽  
Nucleotide Polymorphisms ◽  
Specific Pcr ◽  
Intron Boundary ◽  
Allele Specific ◽  
Exon 9 ◽  
First Time ◽  
Allele Specific Pcr

Objectives. To discuss the mutational features and their relationships with disease in a family with hereditary multiple osteochondroma (HMO) from Guangxi Province (GXBB-1 family), China. Methods. Genomic DNA and total mRNA were extracted from peripheral blood cells of GXBB-1 family members. Whole elements of the EXT1gene and its transcript, including exons, introns, exon-intron boundaries, and coding sequence (CDS) clones, were amplified and sequenced. Allele-specific PCR was used to confirm the position and type of mutation. Results. All patients from the GXBB-1 family harbored the cosegregating heterozygous c.1056+1G>A mutation located in EXT1at an exon-intron boundary. Another three single-nucleotide polymorphisms (SNPs) were also detected in the patients, including IVS2+1G>A in intron 2, c.1844 T>C [p.Pro (CCT) 614Pro (CCC)] in exon 3, and c.2534G>A [p.Glu (GAG) 844Glu (GAA)] in exon 9. The latter two SNPs were synonymous variations. Conclusions. The heterozygous c.1056+1G>A mutation cosegregated with the phenotype, indicating that it is a pathogenic mutation in the GXBB-1 family. This mutation is reported for the first time in Chinese HMO patients. IVS2+1G>A and c.2534G>A have no relationship with the occurrence of disease. However, c.1844 T>C and c.1056+1G>A are linked, and their interaction needs to be further studied. c.1844T>C is a new SNP that has not been reported internationally.

Sign in / Sign up

Export Citation Format

Share Document