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1.
Auris Nasus Larynx ; 43(4): 429-32, 2016 Aug.
Article in English | MEDLINE | ID: mdl-26739947

ABSTRACT

OBJECTIVE: Hereditary hemorrhagic telangiectasia (HHT) is widely known to cause bleeding that is difficult to control because of the associated vascular wall fragility. Although nasal dermoplasty results in decreased severity and frequency of nasal bleeding in patients with HHT, it does not eradicate epistaxis because this procedure cannot cover the entire nasal cavity. Residual bleeding warrants additional effective therapy. Preliminary reports on the use of ß-adrenergic blockers for treating epistaxis in patients with HHT encouraged us to examine their effects in HHT patients who had previously undergone nasal dermoplasty but still complained of epistaxis. METHODS: We performed a prospective topical timolol, a nonselective beta blocker, application study involving 12 HHT patients who had undergone nasal dermoplasty. The observation period lasted for 3 months. RESULTS: There was one improperly enrolled case in which timolol administration was discontinued. The mean score of bleeding intensity and that of bleeding frequency were markedly reduced after treatment. Two patients who had required transfusions before treatment did not need them afterward, and patients were generally satisfied with the treatment. CONCLUSION: Topical timolol application was effective in decreasing epistaxis. Although no adverse effects were observed in the properly selected patients, there are contraindications to timolol application that should be kept in mind when applying this treatment.


Subject(s)
Adrenergic beta-Antagonists/therapeutic use , Epistaxis/prevention & control , Nasal Mucosa/surgery , Skin Transplantation , Telangiectasia, Hereditary Hemorrhagic/surgery , Timolol/therapeutic use , Administration, Topical , Adult , Aged , Epistaxis/etiology , Female , Humans , Male , Middle Aged , Prospective Studies , Severity of Illness Index , Telangiectasia, Hereditary Hemorrhagic/complications
2.
Int J Mol Sci ; 16(11): 26125-36, 2015 Nov 02.
Article in English | MEDLINE | ID: mdl-26540041

ABSTRACT

We previously prepared and evaluated simple Eudragit S100 microparticles loaded with prednisolone (ES-MP) and Eudragit S100-coated chitosan-succinyl-prednisolone conjugate microparticles (Ch-MP/ES) in vitro. In this work, the effectiveness, toxic side effects (5 mg prednisolone (PD) eq/kg × 3 d, 10 mg PD eq/kg × 3 d), and pharmacokinetic characteristics (5 mg PD eq/kg) were examined using rats with colitis induced through 2,4,6-trinitrobenzenesulfonic acid. ES-MP did not change the efficacy or toxic side effects of PD, and this was attributed to incomplete delivery to the target site and prolonged systemic drug absorption by ES-MP. On the other hand, Ch-MP/ES promoted the efficacy of PD and ameliorated its toxic side effects due to better delivery to the target site, very slow drug release and the strong suppression of drug absorption. Only Ch-MP/ES, which markedly changed drug release characteristics, improved the in vivo features of PD.


Subject(s)
Chitosan , Drug Delivery Systems , Microspheres , Polymethacrylic Acids , Prednisolone/administration & dosage , Succinates , Administration, Oral , Animals , Colitis/chemically induced , Colitis/drug therapy , Male , Particle Size , Prednisolone/adverse effects , Prednisolone/pharmacokinetics , Rats , Tissue Distribution
3.
Case Rep Otolaryngol ; 2015: 846832, 2015.
Article in English | MEDLINE | ID: mdl-25699195

ABSTRACT

Objectives. Organized hematoma (OH) is a rare, nonneoplastic, hemorrhagic lesion causing mucosal swelling and bone thinning, mainly in the maxillary sinus. We aimed to clarify the clinical presentation and treatment of OH. Methods. Three cases of maxillary sinus OH and a literature review are presented. Results. Three men aged 16-40 years complained of nasal obstruction, frequent epistaxis, and/or headache. Clinical and radiological examinations revealed a maxillary sinus OH. They were cured in a piecemeal fashion via endoscopic middle meatal antrostomy. Furthermore, vascular endothelial growth factor and its receptor were expressed in the lesion. Conclusions. The pathogenesis of OH is unclear and it presents various histological and imaging findings; however, it is not difficult to rule out malignant tumors. Minimally invasive surgery such as endoscopic sinus surgery can cure it completely. Thus, it is important to determine the diagnosis using CT and MRI and to quickly provide surgical treatment.

4.
Nihon Jibiinkoka Gakkai Kaiho ; 115(2): 108-11, 2012 Feb.
Article in Japanese | MEDLINE | ID: mdl-22568130

ABSTRACT

Hereditary hemorrhagic telangiectasia (HHT)-a systemic autosomal dominant disorder adversely affecting skin, mucous membranes, and visceral blood vessels-typically shows epistaxis. In this pathological condition, even minor stimulation may cause bleeding and hemostasis is unlikely to occur. Subjects with HHT showing severe nasal bleeding require nasal dermoplasty (ND). We report our experience in 22 cases of HHT undergoing ND seen from January 2000 to November 2009. Average age at surgery was 55.8 years. Since April 2008, we modified ND, cut the harvested skin graft from the lateral thigh in halves and spread each strip on the anterior halves of the nasal cavity. Placement was circumferential in the sequence of agger nasi, nasal valve, septum, floor, and inferior turbinate. Before this technique was used, bleeding could not be controlled in 3 of 14 cases. Two of the 3 had histories of arterial embolization. Subjects undergoing the new technique have enjoyed improved quality of life.


Subject(s)
Epistaxis/surgery , Nasal Mucosa/surgery , Skin Transplantation/methods , Telangiectasia, Hereditary Hemorrhagic/surgery , Adult , Aged , Epistaxis/etiology , Female , Humans , Male , Middle Aged , Telangiectasia, Hereditary Hemorrhagic/complications , Transplantation, Autologous
5.
Allergol Int ; 61(1): 115-22, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22377524

ABSTRACT

BACKGROUND: Chronic rhinosinusitis (CRS) is classified in CRS without nasal polyp (CRSsNP) and CRS with nasal polyp (CRSwNP) in western countries, whereas this classification was not common so far in Japan. Studying inflammatory mediators in clearly defined disease subgroups may lead to a better differentiation of chronic sinus diseases. METHODS: Homogenates of sinonasal mucosal tissue from 14 controls, 9 CRSsNP patients, and 19 CRSwNP patients were assayed for transforming growth factor (TGF)-ß, interleukin (IL)-5, immunoglobulin E (IgE), Staphylococcus enterotoxin (SAE)-IgE, eosinophil-catioic protein (ECP), myeloperoxidase (MPO), IL-1ß, IL-6, and IL-8 by enzyme-linked immunosorbent assay or UNICAP system. RESULTS: CRSwNP had significantly higher levels of IL-5, IgE, SAE-IgE, and ECP compared with CRSsNP and controls. CRSsNP was characterized by high levels of TGF-ß, while CRSwNP showed a Th2 polarization and lower levels of TGF-ß. Especially, in CRSwNP samples, 68.4% were eosinophilic (ECP/MPO ratio >1), and 52.6% were SAE-IgE positive. On the other hand, in 9 CRSsNP patients, eosinophilic or SAE-IgE positive sample was only one sample respectively. Additionally, 31.6% of CRSwNP were asthmatic patients, while none of CRSsNP patient was suffering from bronchial asthma. CONCLUSIONS: This study is thought to be the first one that showed the cytokine profiles in Japanese CRSs/wNP similar to those of European CRS. Based on mediator profiles, we suggest that CRSsNP and CRSwNP are distinct disease entities within the group of chronic sinus diseases.


Subject(s)
Cytokines/metabolism , Rhinitis/immunology , Sinusitis/immunology , Adolescent , Adult , Aged , Aged, 80 and over , Chronic Disease , Female , Humans , Immunoglobulin E/immunology , Japan , Male , Middle Aged , Nasal Polyps/immunology , Nasal Polyps/metabolism , Rhinitis/metabolism , Rhinitis/pathology , Sinusitis/metabolism , Sinusitis/pathology , Young Adult
6.
Auris Nasus Larynx ; 39(1): 59-64, 2012 Feb.
Article in English | MEDLINE | ID: mdl-21592697

ABSTRACT

OBJECTIVE: Recurrent epistaxis as a manifestation of hereditary hemorrhagic telangiectasia (HHT) is usually difficult to control. Although no treatment is regarded to be completely efficacious, nostril closure is considered a modality of choice for the most severe cases. The cessation of airflow resulting from this procedure can stop bleeding by minimizing risk factors. However, loss of nasal functions is a disadvantage of nostril closure. We conducted a questionnaire survey of patients who underwent nostril closure surgery, regarding the effects and disadvantages of the operation. METHODS: Seven patients were asked questions on issues including frequency and severity of epistaxis pre- and post-operatively, satisfaction of treatment, and impairment in daily living activities. RESULTS: Most patients reported complete cessation of bleeding. Some still had bleeding, but the frequency and severity were far lower. No transfusions were required in any of the cases. Patients reported some disadvantages, for example, respiratory, olfactory, and phonatory issues. Six out of seven patients were very satisfied with the outcome of surgery. CONCLUSION: Nostril closure surgery can remarkably reduce frequency and volume of epistaxis. Our survey indicated that satisfactory results were achieved. However, difficulties caused by complete nasal obstruction varied. Thus, individualized coping strategies are required.


Subject(s)
Epistaxis/etiology , Epistaxis/surgery , Nasal Surgical Procedures/psychology , Patient Satisfaction , Telangiectasia, Hereditary Hemorrhagic/complications , Aged , Aged, 80 and over , Epistaxis/psychology , Female , Humans , Male , Middle Aged , Postoperative Complications/psychology , Recurrence
7.
Drug Dev Ind Pharm ; 38(7): 800-7, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22077373

ABSTRACT

OBJECTIVE: Simple Eudragit microparticles loaded with prednisolone and chitosan-succinyl-prednisolone conjugate microparticles coated with Eudragit were prepared and characterized in vitro in order to obtain their basic features as a colonic delivery system. MATERIALS AND METHODS: Both types of microparticles were prepared by the emulsification-solvent evaporation modified somewhat from the previous one. Their particle size, shape and their drug content were investigated, and in vitro release profiles were examined using JP-15 1st fluid (pH 1.2), JP-15 2nd fluid (pH 6.8) and PBS (pH 7.4) as release media. Furthermore, the regeneration of conjugate microparticles from Eudragit-coated microparticles was investigated under the same incubation conditions. RESULTS: Simple Eudragit S100 (EuS) microparticles (ES-M) were almost spherical, ca. 1.2 µm diameter, and PD content ca. 3.7% (w/w). Conjugate microparticles (CS-M1) and EuS-coated conjugate microparticles (CS-M1/S) had particle sizes of ca. 2.8 and 15.3 µm, respectively, and PD contents of 5.4 and 2.1% (w/w), respectively. ES-M exhibited suppressed release at pH 1.2, gradual release at pH 6.8 and rapid release at pH 7.4. CS-M1 showed no release at pH 1.2, and very slow release at pH 6.8 and 7.4. CS-M1 regenerated poorly from CS-M1/S at pH 6.8. CONCLUSIONS: Simple Eudragit micrparticles and Eudragit-caoted conjugate microparticles, prepared by the present methods, were found in vitro to be possibly useful as the delivery systems of PD to the lower intestine, although there were differences in their release rate and morphological features.


Subject(s)
Chitosan/chemistry , Drug Delivery Systems , Polymethacrylic Acids/chemistry , Prednisolone/analogs & derivatives , Chemistry, Pharmaceutical/methods , Colon/metabolism , Drug Liberation , Glucocorticoids/administration & dosage , Glucocorticoids/chemistry , Hydrogen-Ion Concentration , Microspheres , Particle Size , Prednisolone/administration & dosage , Prednisolone/chemistry
8.
Laryngoscope ; 121(8): 1715-7, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21792959

ABSTRACT

Nasal dermoplasty is effective in controlling epistaxis in patients with hereditary hemorrhagic telangiectasia (HHT). Skin graft take failure occurs mostly in cases of large septal perforation. The MW method was developed as a modification of nasal dermoplasty designed for patients with HHT having a large septal perforation. It seems to be a safe and effective approach and should be tried for recurrent bleeders with septal perforation.


Subject(s)
Nasal Septum/surgery , Rhinoplasty/methods , Telangiectasia, Hereditary Hemorrhagic/complications , Epistaxis/etiology , Epistaxis/surgery , Humans , Skin Transplantation
9.
Am J Rhinol Allergy ; 24(5): 341-7, 2010.
Article in English | MEDLINE | ID: mdl-21244733

ABSTRACT

BACKGROUND: Nasal polyps are one of the most common findings of physical examination in the otolaryngology area and the experimental model of nasal polyps in the rabbit maxillary sinus is helpful for clarifying the mechanism of polyp formation. Several protocols have been reported for this model, but most of them involved infectious polyps without eosinophil infiltration. We have attempted to establish a novel rabbit model of polyps associated with eosinophil infiltration. METHODS: Rabbits were either untreated (group A) or sensitized with ovalbumin (OVA; groups B-D). After repeated exposure to OVA, some animals further received valine-glycine-serine-glutamine (group C) or poly-L-arginine (group D) in their maxillary sinuses for 4 weeks. Subsequently, sinus tissues were dissected and subjected to histological analysis. The changes in mRNA expression were analyzed by DNA microarray. RESULTS: Remarkable histological changes were observed in groups C and D but not in group B in eosinophil number in the maxillary sinus mucosa, the width of the lamina propria, and polyp scoring. These changes in group D were greater than those in group C. DNA microarray analysis revealed that up-regulated genes in group D included those related to inflammation and extracellular matrix metabolism. On the other hand, down-regulated genes in group D involved those related to anti-inflammation. CONCLUSION: Our results indicate that treatment with inflammatory agents, in combination with an antigen-dependent immune response, could induce nasal polyp formation associated with eosinophil infiltration and mucosal hypertrophy. The gene expression profile supported the clinical relevance of this model.


Subject(s)
Eosinophilia/etiology , Nasal Polyps/etiology , Animals , Eosinophils/pathology , Gene Expression Profiling , Immunoglobulin G/blood , Male , Nasal Mucosa/pathology , Nasal Polyps/pathology , Oligonucleotide Array Sequence Analysis , Ovalbumin/immunology , Peptides , Polymerase Chain Reaction , Rabbits
10.
J Phys Chem B ; 110(11): 5537-41, 2006 Mar 23.
Article in English | MEDLINE | ID: mdl-16539493

ABSTRACT

TiO(2) thin films prepared by a radio frequency magnetron sputtering (RF-MS) deposition method were found to show an enhanced photoelectrochemical response in the visible light region. By controlling the temperature and the gaseous medium during the deposition step, it was possible to control the properties of these films. The photoelectrochemical behavior of the sputtered TiO(2) thin films was compared with that of a commercial TiO(2) sample, and the sputtered films showed higher incident photon to the charge carrier generation efficiency (IPCE of 12.6% at 350 nm) as well as power conversion efficiency (0.33% at 1.84 mW/cm(2)) than the commercial TiO(2) sample. Femtosecond transient absorption spectroscopy experiments have revealed that a major fraction of photogenerated electrons and holes recombine within a few picoseconds, thus limiting photocurrent generation efficiency. The mechanistic insights obtained in the present study should aid in designing semiconductor nanostructures that will maximize the charge separation efficiency and extend the response of the large band gap semiconductor TiO(2) into visible light regions.

11.
Genome Res ; 16(1): 55-65, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16344560

ABSTRACT

By analyzing 1,780,295 5'-end sequences of human full-length cDNAs derived from 164 kinds of oligo-cap cDNA libraries, we identified 269,774 independent positions of transcriptional start sites (TSSs) for 14,628 human RefSeq genes. These TSSs were clustered into 30,964 clusters that were separated from each other by more than 500 bp and thus are very likely to constitute mutually distinct alternative promoters. To our surprise, at least 7674 (52%) human RefSeq genes were subject to regulation by putative alternative promoters (PAPs). On average, there were 3.1 PAPs per gene, with the composition of one CpG-island-containing promoter per 2.6 CpG-less promoters. In 17% of the PAP-containing loci, tissue-specific use of the PAPs was observed. The richest tissue sources of the tissue-specific PAPs were testis and brain. It was also intriguing that the PAP-containing promoters were enriched in the genes encoding signal transduction-related proteins and were rarer in the genes encoding extracellular proteins, possibly reflecting the varied functional requirement for and the restricted expression of those categories of genes, respectively. The patterns of the first exons were highly diverse as well. On average, there were 7.7 different splicing types of first exons per locus partly produced by the PAPs, suggesting that a wide variety of transcripts can be achieved by this mechanism. Our findings suggest that use of alternate promoters and consequent alternative use of first exons should play a pivotal role in generating the complexity required for the highly elaborated molecular systems in humans.


Subject(s)
CpG Islands/genetics , Gene Library , Multigene Family/genetics , Promoter Regions, Genetic/genetics , Quantitative Trait Loci/genetics , Transcription, Genetic/genetics , Base Sequence , Exons/genetics , Humans , Molecular Sequence Data , Organ Specificity , Signal Transduction/genetics
12.
DNA Res ; 12(6): 403-16, 2005.
Article in English | MEDLINE | ID: mdl-16769697

ABSTRACT

The tRNA molecule has an important role in translation, the function of which is to carry amino acids to the ribosomes. It is known that tRNA is transcribed from tRNA genes, some of which, in Eukarya and Archaea, contain introns. A computational analysis of the complete genome of Aeropyrum pernix K1 predicted the presence of 14 intron-containing tRNA genes. To elucidate whether these introns are actually processed in living cells and what mechanism detects the intron regions, cDNAs for premature and mature forms of the tRNA molecules transcribed from the intron-containing tRNA genes in the model aerobic acidothermophilic crenarchaeon, A. pernix K1 were identified and analyzed. A comparison between the nucleotide sequences of these two types of cDNAs indicated that the intron regions of the tRNA molecules were indeed processed in A. pernix K1 living cells. Some cDNA clones showed that the actual splicing positions were different from those predicted by computational analysis. However, the bulge-helix-bulge structure, which has been previously identified in exon-intron boundaries of archaeal tRNA genes, was evident in all boundary regions confirmed in this work. These results indicate that the generally described mechanism for tRNA processing in Archaea is utilized for processing the intron region of the tRNA molecules in A. pernix K1.


Subject(s)
Aeropyrum/genetics , Nucleic Acid Conformation , RNA, Archaeal/genetics , RNA, Transfer/genetics , Base Sequence , DNA, Complementary/genetics , Introns , Molecular Sequence Data
13.
Mol Biol Evol ; 21(9): 1683-91, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15163767

ABSTRACT

Corynebacterium glutamicum, which is the closest relative of Corynebacterium efficiens, is widely used for the large scale production of many kinds of amino acids, particularly glutamic acid and lysine, by fermentation. Corynebacterium diphtheriae, which is well known as a human pathogen, is also closely related to these two species of Corynebacteria, but it lacks such productivity of amino acids. It is an important and interesting question to ask how those closely related bacterial species have undergone such significant functional differentiation in amino acid biosynthesis. The main purpose of the present study is to clarify the evolutionary process of functional differentiation among the three species of Corynebacteria by conducting a comparative analysis of genome sequences. When Mycobacterium and Streptomyces were used as out groups, our comparative study suggested that the common ancestor of Corynebacteria already possessed almost all of the gene sets necessary for amino acid production. However, C. diphtheriae was found to have lost the genes responsible for amino acid production. Moreover, we found that the common ancestor of C. efficiens and C. glutamicum have acquired some of genes responsible for amino acid production by horizontal gene transfer. Thus, we conclude that the evolutionary events of gene loss and horizontal gene transfer must have been responsible for functional differentiation in amino acid biosynthesis of the three species of Corynebacteria.


Subject(s)
Amino Acids/biosynthesis , Corynebacterium/genetics , Corynebacterium/metabolism , Genome, Bacterial , Base Composition , Corynebacterium/pathogenicity , Corynebacterium diphtheriae/genetics , Corynebacterium diphtheriae/metabolism , Corynebacterium diphtheriae/pathogenicity , Corynebacterium glutamicum/genetics , Corynebacterium glutamicum/metabolism , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Evolution, Molecular , Gene Deletion , Gene Transfer, Horizontal , Genes, Bacterial , Humans , Models, Biological , Open Reading Frames , Phylogeny , Species Specificity
14.
Genome Res ; 13(7): 1572-9, 2003 Jul.
Article in English | MEDLINE | ID: mdl-12840036

ABSTRACT

Corynebacterium efficiens is the closest relative of Corynebacterium glutamicum, a species widely used for the industrial production of amino acids. C. efficiens but not C. glutamicum can grow above 40 degrees C. We sequenced the complete C. efficiens genome to investigate the basis of its thermostability by comparing its genome with that of C. glutamicum. The difference in GC content between the species was reflected in codon usage and nucleotide substitutions. Our comparative genomic study clearly showed that there was tremendous bias in amino acid substitutions in all orthologous ORFs. Analysis of the direction of the amino acid substitutions suggested that three substitutions are important for the stability of the C. efficiens proteins: from lysine to arginine, serine to alanine, and serine to threonine. Our results strongly suggest that the accumulation of these three types of amino acid substitutions correlates with the acquisition of thermostability and is responsible for the greater GC content of C. efficiens.


Subject(s)
Amino Acid Substitution/genetics , Corynebacterium/genetics , Genome, Bacterial , Hot Temperature , Sequence Analysis, DNA , Amino Acid Sequence/genetics , Amino Acids/genetics , Amino Acids/metabolism , Bacterial Proteins/chemistry , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Base Composition/genetics , Codon/genetics , Codon/metabolism , Computational Biology , Corynebacterium/enzymology , Corynebacterium/metabolism , DNA, Bacterial/genetics , DNA, Bacterial/metabolism , Molecular Sequence Data , Open Reading Frames/genetics , Polymorphism, Single Nucleotide/genetics , Sequence Analysis, DNA/methods
15.
Nat Biotechnol ; 21(5): 526-31, 2003 May.
Article in English | MEDLINE | ID: mdl-12692562

ABSTRACT

Species of the genus Streptomyces are of major pharmaceutical interest because they synthesize a variety of bioactive secondary metabolites. We have determined the complete nucleotide sequence of the linear chromosome of Streptomyces avermitilis. S. avermitilis produces avermectins, a group of antiparasitic agents used in human and veterinary medicine. The genome contains 9,025,608 bases (average GC content, 70.7%) and encodes at least 7,574 potential open reading frames (ORFs). Thirty-five percent of the ORFs (2,664) constitute 721 paralogous families. Thirty gene clusters related to secondary metabolite biosynthesis were identified, corresponding to 6.6% of the genome. Comparison with Streptomyces coelicolor A3(2) revealed that an internal 6.5-Mb region in the S. avermitilis genome was highly conserved with respect to gene order and content, and contained all known essential genes but showed perfectly asymmetric structure at the oriC center. In contrast, the terminal regions were not conserved and preferentially contained nonessential genes.


Subject(s)
DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Gene Expression Regulation, Bacterial/genetics , Genome, Bacterial , Sequence Alignment/methods , Streptomyces/classification , Streptomyces/genetics , Amino Acid Sequence , Bacterial Proteins/chemistry , Bacterial Proteins/genetics , Base Sequence , Conserved Sequence/genetics , Molecular Sequence Data , Sequence Analysis, DNA/methods , Sequence Analysis, Protein , Sequence Homology , Species Specificity
16.
Biochem Biophys Res Commun ; 291(4): 769-74, 2002 Mar 08.
Article in English | MEDLINE | ID: mdl-11866431

ABSTRACT

A molecular chaperone prefoldin/GimC from the hyperthermophilic archaeum Pyrococcus horikoshii OT3 was characterized. Pyrococcus prefoldin protected porcine heart citrate synthase from thermal aggregation whereas each subunit alone afforded little protection. It also arrested the spontaneous refolding of acid-denatured green fluorescent protein and then transferred it not only to a group II chaperonin from the hyperthermophilic archaeum Thermococcus sp. strain KS-1, but also to a group I chaperonin from the thermophilic bacterium Thermus thermophilus HB8 for subsequent ATP dependent refolding.


Subject(s)
Chaperonins/metabolism , Molecular Chaperones/metabolism , Pyrococcus , Animals , Citrate (si)-Synthase/chemistry , Green Fluorescent Proteins , Hot Temperature , Kinetics , Luminescent Proteins/chemistry , Molecular Chaperones/genetics , Protein Denaturation , Protein Folding , Recombinant Proteins/isolation & purification , Recombinant Proteins/metabolism , Swine
17.
J Bacteriol ; 184(3): 687-94, 2002 Feb.
Article in English | MEDLINE | ID: mdl-11790738

ABSTRACT

Proliferating cell nuclear antigen (PCNA) is an essential component in the eukaryotic DNA replication machinery, in which it works for tethering DNA polymerases on the DNA template to accomplish processive DNA synthesis. The PCNA also interacts with many other proteins in important cellular processes, including cell cycle control, DNA repair, and an apoptotic pathway in the domain EUCARYA: We identified three genes encoding PCNA-like sequences in the genome of Aeropyrum pernix, a crenarchaeal archaeon. We cloned and expressed these genes in Escherichia coli and analyzed the gene products. All three PCNA homologs stimulated the primer extension activities of the two DNA polymerases, polymerase I (Pol I) and Pol II, identified in A. pernix to various extents, among which A. pernix PCNA 3 (ApePCNA3) provided a most remarkable effect on both Pol I and Pol II. The three proteins were confirmed to exist in the A. pernix cells. These results suggest that the three PCNAs work as the processivity factor of DNA polymerases in A. pernix cells under different conditions. In Eucarya, three checkpoint proteins, Hus1, Rad1, and Rad9, have been proposed to form a PCNA-like ring structure and may work as a sliding clamp for the translesion DNA polymerases. Therefore, it is very interesting that three active PCNAs were found in one archaeal cell. Further analyses are necessary to determine whether each PCNA has specific roles, and moreover, how they reveal different functions in the cells.


Subject(s)
Archaeal Proteins/metabolism , DNA-Directed DNA Polymerase/metabolism , Desulfurococcaceae/metabolism , Proliferating Cell Nuclear Antigen/metabolism , Amino Acid Sequence , Archaeal Proteins/genetics , Archaeal Proteins/isolation & purification , Cloning, Molecular , DNA Polymerase I/metabolism , DNA Polymerase II/metabolism , DNA Replication , Desulfurococcaceae/genetics , Eukaryotic Cells , Molecular Sequence Data , Proliferating Cell Nuclear Antigen/genetics , Protein Binding , Sequence Analysis , Sequence Homology, Amino Acid
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