Regulation of mouse CYP1A1 gene expression by dioxin: requirement of two cis-acting elements during induction

1989 ◽  
Vol 9 (6) ◽  
pp. 2378-2386
Author(s):  
L A Neuhold ◽  
Y Shirayoshi ◽  
K Ozato ◽  
J E Jones ◽  
D W Nebert
Keyword(s):  
Gene Expression ◽  
Simian Virus 40 ◽  
Class Ii ◽  
Simian Virus ◽  
Class I ◽  
Ah Receptor ◽  
Class Iii ◽  
Cis Acting ◽  
Cyp1a1 Gene ◽  
Sv40 Dna

The mouse cytochrome P1450 (CYP1A1) gene is responsible for the metabolism of numerous carcinogens and toxic chemicals. Induction by the environmental contaminant tetrachlorodibenzo-p-dioxin (TCDD) requires a functional aromatic hydrocarbon (Ah) receptor. We examined the 5'-flanking region of the CYP1A1 gene in mouse hepatoma Hepa-1 wild-type cells and a mutant line having a defect in chromatin binding of the TCDD-receptor complex. We identified two cis-acting elements (distal, -1071 to -901 region; proximal, -245 to -50 region) required for constitutive and TCDD-inducible CYP1A1 gene expression. Three classes of DNA-protein complexes binding to the distal element were identified: class I, found only in the presence of TCDD and a functional Ah receptor, that was heat labile and not competed against by simian virus 40 (SV40) early promoter DNA; class II, consisting of at least three constitutive complexes that were heat stable and bound to SV40 DNA; and class III, composed of at least three constitutive complexes that were thermolabile and were not competed against by SV40 DNA. Essential contacts for these proteins were centered at -993 to -990 for the class I complex, -987, -986, or both for the class II complexes, and -938 to -927 for the class III complexes. The proximal element was absolutely essential for both constitutive and TCDD-inducible CYP1A1 gene expression, and at least two constitutive complexes bound to this region. These data are consistent with the proximal element that binds proteins being necessary but not sufficient for inducible gene expression; interaction of these proteins with those at the distal element was found to be required for full CYP1A1 induction by TCDD.

scholarly journals Regulation of mouse CYP1A1 gene expression by dioxin: requirement of two cis-acting elements during induction.

1989 ◽  
Vol 9 (6) ◽  
pp. 2378-2386 ◽  
Author(s):  
L A Neuhold ◽  
Y Shirayoshi ◽  
K Ozato ◽  
J E Jones ◽  
D W Nebert
Keyword(s):  
Gene Expression ◽  
Simian Virus 40 ◽  
Class Ii ◽  
Simian Virus ◽  
Class I ◽  
Ah Receptor ◽  
Class Iii ◽  
Cis Acting ◽  
Cyp1a1 Gene ◽  
Sv40 Dna

The mouse cytochrome P1450 (CYP1A1) gene is responsible for the metabolism of numerous carcinogens and toxic chemicals. Induction by the environmental contaminant tetrachlorodibenzo-p-dioxin (TCDD) requires a functional aromatic hydrocarbon (Ah) receptor. We examined the 5'-flanking region of the CYP1A1 gene in mouse hepatoma Hepa-1 wild-type cells and a mutant line having a defect in chromatin binding of the TCDD-receptor complex. We identified two cis-acting elements (distal, -1071 to -901 region; proximal, -245 to -50 region) required for constitutive and TCDD-inducible CYP1A1 gene expression. Three classes of DNA-protein complexes binding to the distal element were identified: class I, found only in the presence of TCDD and a functional Ah receptor, that was heat labile and not competed against by simian virus 40 (SV40) early promoter DNA; class II, consisting of at least three constitutive complexes that were heat stable and bound to SV40 DNA; and class III, composed of at least three constitutive complexes that were thermolabile and were not competed against by SV40 DNA. Essential contacts for these proteins were centered at -993 to -990 for the class I complex, -987, -986, or both for the class II complexes, and -938 to -927 for the class III complexes. The proximal element was absolutely essential for both constitutive and TCDD-inducible CYP1A1 gene expression, and at least two constitutive complexes bound to this region. These data are consistent with the proximal element that binds proteins being necessary but not sufficient for inducible gene expression; interaction of these proteins with those at the distal element was found to be required for full CYP1A1 induction by TCDD.

scholarly journals VisN and VisR Are Global Regulators of Chemotaxis, Flagellar, and Motility Genes in Sinorhizobium (Rhizobium) meliloti

2000 ◽  
Vol 182 (3) ◽  
pp. 782-788 ◽  
Author(s):  
Victor Sourjik ◽  
Paul Muschler ◽  
Birgit Scharf ◽  
Rüdiger Schmitt
Keyword(s):  
Gene Expression ◽  
Rhizobium Meliloti ◽  
Class Ii ◽  
Functional Class ◽  
Class I ◽  
Class Iii ◽  
Transcription Activator ◽  
Western Blots ◽  
Class Iib ◽  
Flagellar Genes

ABSTRACT The known 41 flagellar, chemotaxis, and motility genes ofSinorhizobium (Rhizobium) meliloti contained in the “flagellar regulon” are organized as seven operons and six transcription units that map to a contiguous 45-kb chromosomal region. By probing gene expression on Western blots and with lacZfusions, we have identified two master regulatory genes,visN and visR, contained in one operon. The gene products probably form a heterodimer, VisNR, acting as a global transcription activator of other flagellar genes. The related 27-kDa VisN and VisR proteins are LuxR-type proteins with typical ligand- and DNA-binding domains. The vis operon itself is constitutively transcribed; however, to activate flagellar genes, VisNR seemingly requires the binding of a yet-unknown effector. Gene expression in tester strains with known deficiencies revealed a hierarchy of three classes of flagellar genes: class I comprisesvisN and visR; class II, controlled by VisNR, comprises flagellar assembly (class IIA) and motor (class IIB) genes; and class III comprises flagellin and chemotaxis genes that require functional class I and class IIA genes for expression. In contrast to their enterobacterial counterparts, mot genes belong to class II without exerting control over class III genes. While the general hierarchy of gene expression resembles the enterobacterial scheme, the assignment of mot genes to class IIB and the global control by a LuxR-type VisNR activator are new features distinguishing the S. meliloti flagellar gene system.

Sequence-dependent DNA replication in preimplantation mouse embryos

1985 ◽  
Vol 5 (11) ◽  
pp. 2924-2935
Author(s):  
D O Wirak ◽  
L E Chalifour ◽  
P M Wassarman ◽  
W J Muller ◽  
J A Hassell ◽  
...  
Keyword(s):  
Dna Replication ◽  
Dna Sequences ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Mouse Embryos ◽  
Origin Of Replication ◽  
Mouse Development ◽  
Cis Acting ◽  
Sv40 Dna

Circular, double-stranded DNA molecules were injected into nuclei of mouse oocytes and one- or two-cell embryos to determine whether specific sequences were required to replicate DNA during mouse development. Although all of the injected DNAs were stable, replication of plasmid pML-1 DNA was not detected unless it contained either polyomavirus (PyV) or simian virus 40 (SV40) DNA sequences. Replication occurred in embryos, but not in oocytes. PyV DNA, either alone or recombined with pML-1, underwent multiple rounds of replication to produce superhelical and relaxed circular monomers after injection into one- or two-cell embryos. SV40 DNA also replicated, but only 3% as well as PyV DNA. Coinjection of PyV DNA with either pML-1 or SV40 had no effect on the replicating properties of the three DNAs. These results are consistent with a requirement for specific cis-acting sequences to replicate DNA in mammalian embryos, in contrast to sequence-independent replication of DNA injected into Xenopus eggs. Furthermore, PyV DNA replication in mouse embryos required PyV large T-antigen and either the alpha-beta-core or beta-core configuration of the PyV origin of replication. Although the alpha-core configuration replicated in differentiated mouse cells, it failed to replicate in mouse embryos, demonstrating cell-specific activation of an origin of replication. Replication or expression of PyV DNA interfered with normal embryonic development. These results reveal that mouse embryos are permissive for PyV DNA replication, in contrast to the absence of PyV DNA replication and gene expression in mouse embryonal carcinoma cells.

scholarly journals Sequence-dependent DNA replication in preimplantation mouse embryos.

1985 ◽  
Vol 5 (11) ◽  
pp. 2924-2935 ◽  
Author(s):  
D O Wirak ◽  
L E Chalifour ◽  
P M Wassarman ◽  
W J Muller ◽  
J A Hassell ◽  
...  
Keyword(s):  
Dna Replication ◽  
Dna Sequences ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Mouse Embryos ◽  
Origin Of Replication ◽  
Mouse Development ◽  
Cis Acting ◽  
Sv40 Dna

Circular, double-stranded DNA molecules were injected into nuclei of mouse oocytes and one- or two-cell embryos to determine whether specific sequences were required to replicate DNA during mouse development. Although all of the injected DNAs were stable, replication of plasmid pML-1 DNA was not detected unless it contained either polyomavirus (PyV) or simian virus 40 (SV40) DNA sequences. Replication occurred in embryos, but not in oocytes. PyV DNA, either alone or recombined with pML-1, underwent multiple rounds of replication to produce superhelical and relaxed circular monomers after injection into one- or two-cell embryos. SV40 DNA also replicated, but only 3% as well as PyV DNA. Coinjection of PyV DNA with either pML-1 or SV40 had no effect on the replicating properties of the three DNAs. These results are consistent with a requirement for specific cis-acting sequences to replicate DNA in mammalian embryos, in contrast to sequence-independent replication of DNA injected into Xenopus eggs. Furthermore, PyV DNA replication in mouse embryos required PyV large T-antigen and either the alpha-beta-core or beta-core configuration of the PyV origin of replication. Although the alpha-core configuration replicated in differentiated mouse cells, it failed to replicate in mouse embryos, demonstrating cell-specific activation of an origin of replication. Replication or expression of PyV DNA interfered with normal embryonic development. These results reveal that mouse embryos are permissive for PyV DNA replication, in contrast to the absence of PyV DNA replication and gene expression in mouse embryonal carcinoma cells.

scholarly journals Environmental Cadmium Exposure and Dental Indices in Orthodontic Patients

Healthcare ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 413
Author(s):  
Hui-Ling Chen ◽  
Jason Chen-Chieh Fang ◽  
Chia-Jung Chang ◽  
Ti-Feng Wu ◽  
I-Kuan Wang ◽  
...  
Keyword(s):  
Cadmium Concentration ◽  
Class Ii ◽  
Cadmium Exposure ◽  
Class I ◽  
P Value ◽  
Tooth Decay ◽  
Class Iii ◽  
Orthodontic Patients ◽  
Urine Cadmium ◽  
The Mean

Background. Previous studies have shown that environmental cadmium exposure could disrupt salivary gland function and is associated with dental caries and reduced bone density. Therefore, this cross-sectional study attempted to determine whether tooth decay with tooth loss following cadmium exposure is associated with some dental or skeletal traits such as malocclusions, sagittal skeletal pattern, and tooth decay. Methods. Between August 2019 and June 2020, 60 orthodontic patients with no history of previous orthodontics, functional appliances, or surgical treatment were examined. The patients were stratified into two groups according to their urine cadmium concentrations: high (>1.06 µg/g creatinine, n = 28) or low (<1.06 µg/g creatinine, n = 32). Results. The patients were 25.07 ± 4.33 years old, and most were female (female/male: 51/9 or 85%). The skeletal relationship was mainly Class I (48.3%), followed by Class II (35.0%) and Class III (16.7%). Class I molar relationships were found in 46.7% of these patients, Class II molar relationships were found in 15%, and Class III molar relationships were found in 38.3%. The mean decayed, missing, and filled surface (DMFS) score was 8.05 ± 5.54, including 2.03 ± 3.11 for the decayed index, 0.58 ± 1.17 for the missing index, and 5.52 ± 3.92 for the filled index. The mean index of complexity outcome and need (ICON) score was 53.35 ± 9.01. The facial patterns of these patients were within the average low margin (26.65 ± 5.53 for Frankfort–mandibular plane angle (FMA)). There were no significant differences in the above-mentioned dental indices between patients with high urine cadmium concentrations and those with low urine cadmium concentrations. Patients were further stratified into low (<27, n = 34), average (27–34, n = 23), and high (>34, n = 3) FMA groups. There were no statistically significant differences in the urine cadmium concentration among the three groups. Nevertheless, a marginally significant p-value of 0.05 for urine cadmium concentration was noted between patients with low FMA and patients with high FMA. Conclusion. This analysis found no association between environmental cadmium exposure and dental indices in our orthodontic patients.

scholarly journals Template Structural Requirements for Transcription In Vivo by RNA Polymerase II

1982 ◽  
Vol 2 (12) ◽  
pp. 1595-1607 ◽  
Author(s):  
Timothy J. Miller ◽  
Janet E. Mertz
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Rna Polymerase Iii ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
Structural Requirements ◽  
Infected Monkey ◽  
Full Complement ◽  
Sv40 Dna

Purified simian virus 40 (SV40) DNA is reconstituted into chromatin and transcribed by endogenous RNA polymerase II when microinjected into nuclei ofXenopus laevisoocytes. We have correlated the kinetics of chromatin reconstitution with that of accumulation of virus-specific RNA in this system. A delay of approximately 3 h was found in the appearance of appreciable numbers of both fully supercoiled molecules and transcriptionally active templates. SV40 minichromosomes, isolated from virus-infected monkey cells with 0.2 M NaCl, also exhibited this lag in onset of transcriptional activity when microinjected into oocytes. These findings indicate that neither purified SV40 DNA nor SV40 DNA containing a full complement of nucleosomes can function as a template for transcription in vivo before association with appropriate cellular nonhistone chromosomal factors has taken place. In addition, the gradual degradation of linear SV40 DNA in oocytes was not sufficient to account for the fact that it was much less transcriptionally active than circular SV40 DNA. Taken together, these results indicate that the conformational state of the DNA can affect its ability to function as a template for transcription in vivo by RNA polymerase II. In contrast, transcription by RNA polymerase III of purified, circularized cloned DNAs encoding genes for 5S rRNA was detectable long before the injected DNAs had time to reconstitute into chromatin. Therefore, the template structural requirements for transcription in vivo by RNA polymerases II and III are different.

scholarly journals In vivo competition of delta-crystallin gene expression by DNA fragments containing a GC box.

1986 ◽  
Vol 6 (11) ◽  
pp. 4130-4132 ◽  
Author(s):  
S Hayashi ◽  
H Kondoh
Keyword(s):  
Gene Expression ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
Dna Fragments ◽  
Specific Expression ◽  
Mouse Cells ◽  
Gc Box ◽  
Simplex Virus

Expression of the chicken delta-crystallin gene 1 injected into the nuclei of mouse cells is lens specific. Coinjection of GC box-containing DNA fragments from delta-crystallin, simian virus 40 early, and herpes simplex virus type 1 tk promoters effectively suppressed delta-crystallin expression in the lens, but coinjection with DNA fragments not containing the GC box did not. This suppression was likely due to the competition of an Sp1-like transcription factor(s) and indicates involvement of the apparently ubiquitous factor(s) in the tissue-specific expression of the delta-crystallin gene.

scholarly journals A convenient method of preparation of high-activity urease from Canavalia ensiformis by covalent chromatography and an investigation of its thiol groups with 2,2'-dipyridyl disulphide as a thiol titrant and reactivity probe

1976 ◽  
Vol 159 (2) ◽  
pp. 245-257 ◽  
Author(s):  
R Norris ◽  
K Brocklehurst
Keyword(s):  
Convenient Method ◽  
Specific Activity ◽  
Class Ii ◽  
High Reactivity ◽  
Class I ◽  
Thiol Groups ◽  
Class Iii ◽  
Active Centre ◽  
Class Ib ◽  
Covalent Chromatography

1. A convenient method of preparation of jack-bean urease (EC3.5.1.5) involving covalent chromatography by thiol-disulphide interchange is described. 2. Urease thus prepared has specific activity comparable with the highest value yet reported (44.5 ± 1.47 kat/kg, Km = 3.32 ± 0.05 mM; kcat. = 2.15 × 104 ± 0.05 × 104s-1 at pH7.0 and 38°C). 3. Titration of the urease thiol groups with 2,2'-dipyridyl disulphide (2-Py-S-S-2-Py) and application of the method of Tsou Chen-Lu [(1962) Sci. Sin.11, 1535-1558] suggests that the urease molecule (assumed to have mol.wt. 483000 and ε280 = 2.84 × 105 litre·mol-1-cm-1) contains 24 inessential thiol groups of relatively high reactivity (class-I), six ‘essential’ thiol groups of low reactivity (class-II) and 54 buried thiol groups (class-III) which are exposed in 6M-guanidinium chloride. 4. The reaction of the class-I thiol groups with 2-Py-S-S-2-Py was studied in the pH range 6-11 at 25°C(I = 0.1 mol/l) by stopped-flow spectrophotometry, and the analogous reaction of the class-II thiol groups by conventional spectrophotometry. 5. The class-I thiol groups consist of at least two sub-classes whose reactions with 2-Py-S-S-2-Py are characterized by (a) pKa = 9.1, k = 1.56 × 104M-1·s-1 and (b) pKa = 8.1, k = 8.05 × 102M-1·s-1 respectively. The reaction of the class-II thiol groups is characterized by pKa = 9.15 and k = 1.60 × 102M-1·s-1. 6. At pH values 7-8 the class-I thiol groups consist of approx. 50% class-Ia groups and 50% class-Ib groups. The ratio class Ia/class Ib decreases as the pH is raised according to a pKa value ≥ approx. 9.5, and at high pH the class-I thiol groups consist of at most 25% class-Ia groups and at least 75% class-Ib groups. 7. The reactivity of the class-II thiol groups towards 2-Py-S-S-2-Py is insensitive to the nature of the group used to block the class-I thiols. 8. All the ‘essential’ thiol groups in urease appear to be eeactive only as uncomplicated thiolate ions. The implications of this for the active-centre chemistry of urease relative to that of the thiol proteinases are discussed.

Replication of cloned DNA containing the Alu family sequence during cell extract-promoting simian virus 40 DNA synthesis

1984 ◽  
Vol 4 (8) ◽  
pp. 1476-1482
Author(s):  
H Ariga
Keyword(s):  
Dna Replication ◽  
Dna Synthesis ◽  
Rna Polymerase Iii ◽  
Simian Virus 40 ◽  
Cell Extract ◽  
Simian Virus ◽  
T Antigen ◽  
Sv40 T Antigen ◽  
Sv40 Dna

The replicating activity of several cloned DNAs containing putative origin sequences was examined in a cell-free extract that absolutely depends on simian virus 40 (SV40) T antigen promoting initiation of SV40 DNA replication in vitro. Of the three DNAs containing the human Alu family sequence (BLUR8), the origin of (Saccharomyces cerevisiae plasmid 2 micron DNA (pJD29), and the yeast autonomous replicating sequence (YRp7), only BLUR8 was active as a template. Replication in a reaction mixture with BLUR8 as a template was semiconservative and not primed by a putative RNA polymerase III transcript synthesized on the Alu family sequence in vitro. Pulse-chase experiments showed that the small-sized DNA produced in a short-term incubation was converted to full-length closed circular and open circular DNAs in alkaline sucrose gradients. DNA synthesis in extracts began in a region of the Alu family sequence and was inhibited 80% by the addition of anti-T serum. Furthermore, partially purified T antigen bound the Alu family sequence in BLUR8 by the DNA-binding immunoassay. These results suggest that SV40 T antigen recognizes the Alu family sequence, similar to the origin sequence of SV40 DNA, and initiates semiconservative DNA replication in vitro.

Prevalence of Malocclusions in Autistic Patients in Isfahan

2021 ◽  
Author(s):  
Zahra Ali Mehtari ◽  
Mehdi Rafiei ◽  
Saeed Azarbayjani ◽  
Neda Ahmadi Rouzbehani ◽  
Amir Hossain Moeini
Keyword(s):  
Class Ii ◽  
Autism Spectrum ◽  
Open Bite ◽  
Class I ◽  
Dental Student ◽  
Class Iii ◽  
Cross Sectional ◽  
Deep Bite ◽  
Normal Occlusion ◽  
Age Range

Introduction: Autism spectrum disorder (ASD) is a group of neurodevelopmental disorders diagnosed by impairments in social interaction and communication with repetitive and restrictive stereotyped behavioral patterns. The Prevalence of autism has been reported to be increased in recent years. This study aimed to assess the prevalence of different types of malocclusion among ASD patients in Isfahan in 2018. Materials & Methods: In a descriptive and cross-sectional trial, 92 ASD patients were studied in the age range of 7-18 years at the center for autism patients in Isfahan. Clinical oral examinations of patients are taken to assess the involved malocclusions (Cl I, Cl II and Cl III malocclusions) and malocclusion traits (deep bite, open bite and cross bite) by an educated dental student under the supervision of an orthodontist under natural light. The data are reported using frequency and percentage indices. Results: Class I malocclusion had the highest prevalence 54.3% (50) among ASD patients and the prevalence of class II and class III were found to be 19.6% (18) and 7.6% (7) respectively. The frequency of malocclusions traits of deep bite, cross bite and the open bite were 27.2% (25), 18.5% (17) and 7.6% (7) respectively. Among of the total patients, 65.2% (60) showed normal bite and 18/5% (17) showed Normal occlusion. Conclusion: ASD patients showed class I, class II and class III malocclusions from the most to least frequency and the most frequent malocclusion traits were also deep bite, cross bite and open bite respectively.

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