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125 records – page 1 of 13.

Accumulation and exchange of parasites during adaptive radiation in an ancient lake.

https://arctichealth.org/en/permalink/ahliterature301785
Source
Int J Parasitol. 2018 03; 48(3-4):297-307
Publication Type
Journal Article
Date
03-2018
Author
Joseph E Ironside
Toby J Wilkinson
Author Affiliation
Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, Ceredigion SY23 3DA, United Kingdom. Electronic address: jei@aber.ac.uk.
Source
Int J Parasitol. 2018 03; 48(3-4):297-307
Date
03-2018
Language
English
Publication Type
Journal Article
Keywords
Adaptation, Biological
Amphipoda - classification - parasitology - physiology
Animals
Bayes Theorem
Biodiversity
Cloning, Molecular
DNA, Fungal - chemistry
DNA, Ribosomal - chemistry
Europe
Host Specificity
Lakes - parasitology
Microsporidia - classification - genetics - growth & development
Phylogeny
Ponds - parasitology
Rivers - parasitology
Russia
Abstract
In the ancient Lake Baikal, Russia, amphipod crustaceans have undergone a spectacular adaptive radiation, resulting in a diverse community of species. A survey of microsporidian parasites inhabiting endemic and non-endemic amphipod host species at the margins of Lake Baikal indicates that the endemic amphipods harbour many microsporidian parasite groups associated with amphipods elsewhere in Eurasia. While these parasites may have undergone a degree of adaptive radiation within the lake, there is little evidence of host specificity. Furthermore, a lack of reciprocal monophyly indicates that exchanges of microsporidia between Baikalian and non-Baikalian hosts have occurred frequently in the past and may be ongoing. Conversely, limitations to parasite exchange between Baikalian and non-Baikalian host populations at the margins of the lake are implied by differences in parasite prevalence and lack of shared microsporidian haplotypes between the two host communities. While amphipod hosts have speciated sympatrically within Lake Baikal, the parasites appear instead to have accumulated, moving into the lake from external amphipod populations on multiple occasions to exploit the large and diverse community of endemic amphipods in Lake Baikal.
PubMed ID
29273284 View in PubMed
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Alpha-methylacyl-CoA racemase from Mycobacterium tuberculosis. Mutational and structural characterization of the active site and the fold.

https://arctichealth.org/en/permalink/ahliterature69307
Source
J Biol Chem. 2005 Apr 1;280(13):12611-20
Publication Type
Article
Date
Apr-1-2005
Author
Kalle Savolainen
Prasenjit Bhaumik
Werner Schmitz
Tiina J Kotti
Ernst Conzelmann
Rik K Wierenga
J Kalervo Hiltunen
Author Affiliation
Biocenter Oulu and Department of Biochemistry, University of Oulu, Linnanmaa, P. O. Box 3000, FIN-90014 University of Oulu, Finland.
Source
J Biol Chem. 2005 Apr 1;280(13):12611-20
Date
Apr-1-2005
Language
English
Publication Type
Article
Keywords
Alanine - chemistry
Amino Acid Sequence
Animals
Bile Acids and Salts - metabolism
Binding Sites
Catalysis
Circular Dichroism
Cloning, Molecular
Crystallography, X-Ray
Dimerization
Escherichia coli - metabolism
Models, Chemical
Models, Molecular
Molecular Sequence Data
Mutation
Mycobacterium tuberculosis - enzymology - genetics
Protein Conformation
Protein Folding
Protein Structure, Secondary
Racemases and Epimerases - chemistry - genetics
Rats
Research Support, Non-U.S. Gov't
Sequence Homology, Amino Acid
Substrate Specificity
Ultraviolet Rays
Abstract
Alpha-methylacyl-CoA racemase (Amacr) catalyzes the racemization of alpha-methyl-branched CoA esters. Sequence comparisons have shown that this enzyme is a member of the family III CoA transferases. The mammalian Amacr is involved in bile acid synthesis and branched-chain fatty acid degradation. In human, mutated variants of Amacr have been shown to be associated with disease states. Amino acid sequence alignment of Amacrs and its homologues from various species revealed 26 conserved protic residues, assumed to be potential candidates as catalytic residues. Amacr from Mycobacterium tuberculosis (MCR) was taken as a representative of the racemases. To determine their importance for efficient catalysis, each of these 26 protic residues of MCR was mutated into an alanine, respectively, and the mutated variants were overexpressed in Escherichia coli. It was found that four variants (R91A, H126A, D156A, and E241A) were properly folded but had much decreased catalytic efficiency. Apparently, Arg91, His126, Asp156, and Glu241 are important catalytic residues of MCR. The importance of these residues for catalysis can be rationalized by the 1.8 A resolution crystal structure of MCR, which shows that the catalytic site is at the interface between the large and small domain of two different subunits of the dimeric enzyme. This crystal structure is the first structure of a complete enzyme of the bile acid synthesis pathway. It shows that MCR has unique structural features, not seen in the structures of the sequence related formyl-CoA transferases, suggesting that the family III CoA transferases can be subdivided in at least two classes, being racemases and CoA transferases.
PubMed ID
15632186 View in PubMed
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An AB recombinant and its parental HIV type 1 strains in the area of the former Soviet Union: low requirements for sequence identity in recombination. UNAIDS Virus Isolation Network.

https://arctichealth.org/en/permalink/ahliterature7511
Source
AIDS Res Hum Retroviruses. 2000 Jul 20;16(11):1047-53
Publication Type
Article
Date
Jul-20-2000
Author
K. Liitsola
K. Holm
A. Bobkov
V. Pokrovsky
T. Smolskaya
P. Leinikki
S. Osmanov
M. Salminen
Author Affiliation
Department of Infectious Disease Epidemiology, National Public Health Institute, Helsinki, Finland. kirsi.liitsola@ktl.fi
Source
AIDS Res Hum Retroviruses. 2000 Jul 20;16(11):1047-53
Date
Jul-20-2000
Language
English
Publication Type
Article
Keywords
Base Sequence
Cloning, Molecular
Genes, env
Genome, Viral
HIV Infections - epidemiology - virology
HIV-1 - classification - genetics
Humans
Male
Molecular Sequence Data
Phylogeny
Polymerase Chain Reaction
Recombination, Genetic
Research Support, Non-U.S. Gov't
Russia - epidemiology
Sequence Analysis, DNA
Substance Abuse, Intravenous - complications
Ukraine - epidemiology
Abstract
In the former Soviet Union (SU) increasing numbers of HIV-1 infections among injecting drug users (IDU) have been reported, especially in the Ukraine. The main subtype transmitted among the IDUs seems to be subtype A, but limited numbers of subtype B cases have also been reported. In Kaliningrad, Russia, an AB recombinant strain was earlier shown to be responsible for the local outbreak. Here we describe the genetic relationship of HIV-1 strains circulating among IDUs in the former SU. For subtype A and the AB recombinant strains nearly full-length genomes were sequenced, and for one subtype B strain the entire envelope gene was cloned. The relationship between the AB recombinant strain and the subtype A and subtype B strains and the mosaic structure of the recombinant was studied by phylogenetic analysis. Ukrainian A and B strains were shown to be the probable parental viruses of the Kaliningrad AB recombinant strain. In the envelope gene the recombination breakpoint could also be precisely mapped to a region of similarity of only 14 base pairs. This suggests that only short stretches of absolute sequence identity may be needed for efficient RNA recombination between HIV-1 subtypes.
PubMed ID
10933619 View in PubMed
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Analysis of T-DNA insertion sites in transgenic tobacco plants with mutant phenotype.

https://arctichealth.org/en/permalink/ahliterature69054
Source
Dokl Biochem. 2000 Jan-Feb;370(1-6):16-9
Publication Type
Article

[An analysis of the cDNA nucleotide sequence for the C-terminal fragment of the coat protein in tobacco mosaic virus isolates from tobacco growing in an ecological niche of Polesye, Ukraine]

https://arctichealth.org/en/permalink/ahliterature69071
Source
Tsitol Genet. 1998 Apr-May;32(3):30-5
Publication Type
Article
Author
A L Boiko
S A Stepaniuk
O M Garifulin
Source
Tsitol Genet. 1998 Apr-May;32(3):30-5
Language
Russian
Publication Type
Article
Keywords
Amino Acid Sequence
Base Sequence
Capsid - chemistry - genetics
Cesium radioisotopes
Cloning, Molecular - methods
DNA, Complementary - genetics
DNA, Viral - genetics
Ecosystem
English Abstract
Molecular Sequence Data
Peptide Fragments - chemistry - genetics
Plants, Toxic
Radioactive Pollutants
Tobacco - virology
Tobacco Mosaic Virus - genetics - isolation & purification
Ukraine
Abstract
Two identical strains of tobacco type TVM have been isolated in the region with 137Cs nuclear contamination with density of 12.6 Cu/km2 recombinant plasmids (pTVM9, pTVM9,5) containing cDNA of complete provirus and C-end sequence of cDNA of specific capsid protein from one of isolated viruses have been obtained. The capsule proteins of isolated strains have the higher 19.5 +/- 1.9 kDa molecular weight than standard TVM strain (17.5 kDa) as to SDS-PAAG electrophoresis data. No differences in distribution of fragments immunoactive to control antiserum have been found when using immunoblot analysis of capsid proteins of isolates and standard strain treated by tripsin. Sequencing analysis of cDNA pTVM9,5 has revealed non-conservative amino acid replacement of serine by tyrosine in position 149 for homologous region of capsid protein of standard TVM strain, which allows to suppose the mediated effect of specific ecological situation on the appearance of such replacement.
PubMed ID
9879105 View in PubMed
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An intrinsically disordered domain in Polaribacter irgensii KOPRI 22228 CspB confers extraordinary freeze-tolerance.

https://arctichealth.org/en/permalink/ahliterature289779
Source
Biochem Biophys Res Commun. 2018 02 05; 496(2):374-380
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Date
02-05-2018
Author
Youn Hong Jung
Ji-Hyun Uh
Kyunghee Lee
Hana Im
Author Affiliation
Department of Molecular Biology, Sejong University, 209 Neungdong-ro, Gunja-dong, Gwangjin-gu, Seoul 05006, Republic of Korea.
Source
Biochem Biophys Res Commun. 2018 02 05; 496(2):374-380
Date
02-05-2018
Language
English
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Keywords
Adaptation, Physiological - genetics
Bacterial Proteins - chemistry - genetics - metabolism
Cloning, Molecular
Cold Temperature
DNA-Binding Proteins - chemistry - genetics - metabolism
Escherichia coli - genetics - metabolism
Flavobacteriaceae - genetics - metabolism
Gene Expression
Intrinsically Disordered Proteins - chemistry - genetics - metabolism
Liposomes - chemistry - metabolism
Mutation
Protein Binding
Protein Domains
Recombinant Proteins - chemistry - genetics - metabolism
Stress, Physiological
Abstract
Organisms living in extremely cold environments possess mechanisms to survive low temperatures. Among the known cold-induced genes, cold-shock proteins (Csps) are the most prominent. A csp-homologous gene, cspBPi, has been cloned from the Arctic bacterium Polaribacter irgensii KOPRI 22228, and overexpression of this gene greatly increased the freezing tolerance of its host. This protein consists of a unique N-terminal domain and a well conserved C-terminal cold shock domain. To elucidate the detailed mechanisms involved in the extraordinary freeze-tolerance conferred by CspBPi, we identified the responsible domain by mutational analysis. Changes of residues in the cold shock domain that are crucial for binding RNA or single-stranded DNA did not impair the ability of the host to survive freezing stress. All domain-shuffled CspBPi variants containing the N-terminal domain retained the ability to confer superior freeze-tolerance. Slow electrophoretic mobility and far-UV circular dichroism spectra of the N-terminal domain suggested an intrinsically disordered structure for this region. The N-terminal domain also bound to lipid vesicles in vitro. This lipid vesicle binding characteristic is shared with other intrinsically disordered proteins, such as a-synuclein and plant dehydrins, known to confer cold-tolerance when overexpressed, suggesting a mechanism for cold-survival through membrane binding.
PubMed ID
29330047 View in PubMed
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Application of a yeast estrogen screen in non-biomarker species Varicorhinus barbatulus fish with two estrogen receptor subtypes to assess xenoestrogens.

https://arctichealth.org/en/permalink/ahliterature165448
Source
Toxicol In Vitro. 2007 Jun;21(4):604-12
Publication Type
Article
Date
Jun-2007
Author
Keng-Yen Fu
Chung-Yuan Chen
Whei-Meih Chang
Author Affiliation
Institute of Environmental Engineering, National Chiao Tung University, Hsinchu 300, Taiwan, ROC.
Source
Toxicol In Vitro. 2007 Jun;21(4):604-12
Date
Jun-2007
Language
English
Publication Type
Article
Keywords
Animals
Cloning, Molecular
Cyprinidae - physiology
Environmental Pollutants - toxicity
Estrogen Receptor alpha - drug effects - genetics - metabolism
Estrogen Receptor beta - drug effects - genetics - metabolism
Estrogens, Non-Steroidal - toxicity
Female
Humans
Ligands
Liver - drug effects - metabolism
Oncorhynchus mykiss
Receptors, Estrogen - drug effects - genetics - metabolism
Transcriptional Activation - genetics
Xenobiotics - toxicity
Yeasts - genetics - metabolism
Abstract
Xenoestrogens can interfere with normal estrogen signaling by competitively binding to the estrogen receptor (ER) and activating transcription of target genes. In this study, we cloned the estrogen receptor alpha (vbERalpha) and beta 2 (vbERbeta2) genes from liver of the indigenous Taiwanese cyprinid fish Varicorhinus barbatulus and tested the direct impact of several xenoestrogens on these ERs. Transcriptional activity of xenoestrogens was measured by the enzymatic activity of estrogen responsive element (ERE)-containing beta-galactosidase in a yeast reporter system. The xenoestrogens tested were phenol derivatives, DDT-related substances, phthalic acid esters, and polychlorinated biphenyls, with 17beta-estradiol (E2) as a subjective standard. The phenol derivatives [4-nonylphenol (4-NP), 4-t-octylphenol (4-t-OP) and bisphenol A (BPA)] exhibited significant dose-dependent responses in both ligand potency and ligand efficiency. Consistent with yeast assays using human or rainbow trout ERs, we observed a general subtype preference in that vbERalpha displayed higher relative potencies and efficiencies than vbERbeta2, although our assays induced a stronger response for xenoestrogens than did human or trout ERs. Whereas 4-NP and 4-t-OP have similar EC50 values relative to E2 for both ER subtypes, the strong estrogenic response of BPA markedly differentiates vbERalpha from vbERbeta2, suggesting possible species-specific BPA sensitivity. We report that the ameliorative yeast tool is readily applicable for indigenous wildlife studies of the bio-toxic influence of xenoestrogens with wildlife-specific estrogen receptors.
PubMed ID
17258427 View in PubMed
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Assembly of a 1-Mb restriction-mapped cosmid contig spanning the candidate region for Finnish congenital nephrosis (NPHS1) in 19q13.1.

https://arctichealth.org/en/permalink/ahliterature211815
Source
Genomics. 1996 Jun 1;34(2):223-5
Publication Type
Article
Date
Jun-1-1996
Author
A S Olsen
A. Georgescu
S. Johnson
A V Carrano
Author Affiliation
Human Genome Center, Lawrence Livermore National Laboratory, Livermore, California, 94551, USA.
Source
Genomics. 1996 Jun 1;34(2):223-5
Date
Jun-1-1996
Language
English
Publication Type
Article
Keywords
Chromosome Mapping
Chromosomes, Human, Pair 19
Cloning, Molecular
Cosmids
Deoxyribonuclease EcoRI
Exons
Finland - epidemiology
Gene Library
Genes, Recessive
Genetic markers
Humans
Incidence
Nephrosis - congenital - epidemiology - genetics
Restriction Mapping
Abstract
We describe the assembly of a 1-Mb cosmid contig and restriction map spanning the candidate region for Finnish congenital nephrosis (NPHS1) in 19q13.1. The map was constructed from 16 smaller contigs assembled by fingerprinting, a BAC and a PAC clone, and 42 previously unmapped cosmids. In most cases, single-step cosmid walks were sufficient to join two previously assembled contigs, and all but one gap was filled from this cosmid contig library. The remaining gap of about 19 kb was spanned with a single BAC and a single PAC clone. EcoRI mapping of a dense set of overlapping clones validated the assembly of the map and indicated a length of 1040 kb for the contig. This high-resolution clone map provides an ideal resource for gene identification through cDNA selection, exon trapping, and DNA sequencing.
PubMed ID
8661053 View in PubMed
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Assembly of a high-resolution map of the Acadian Usher syndrome region and localization of the nuclear EF-hand acidic gene.

https://arctichealth.org/en/permalink/ahliterature205307
Source
Biochim Biophys Acta. 1998 Jul 1;1407(1):84-91
Publication Type
Article
Date
Jul-1-1998
Author
M M DeAngelis
J P Doucet
S. Drury
S T Sherry
M B Robichaux
Z. Den
M Z Pelias
G M Ditta
B J Keats
P L Deininger
M A Batzer
Author Affiliation
Department of Pathology, Louisiana State University Medical Center, 1901 Perdido Street, New Orleans, LA 70112, USA.
Source
Biochim Biophys Acta. 1998 Jul 1;1407(1):84-91
Date
Jul-1-1998
Language
English
Publication Type
Article
Keywords
Bacteriophage P1 - genetics
Calcium-Binding Proteins
Canada - ethnology
Chromosome Mapping
Chromosomes, Artificial, Yeast
Chromosomes, Human, Pair 11
Cloning, Molecular
DNA-Binding Proteins - genetics
France - ethnology
Hearing Loss, Sensorineural - classification - epidemiology - genetics
Humans
Louisiana - epidemiology
Microsatellite Repeats
Nerve Tissue Proteins
Retinitis Pigmentosa - classification - epidemiology - genetics
Sequence Analysis, DNA
Syndrome
Abstract
Usher syndrome type 1C (USH1C) occurs in a small population of Acadian descendants from southwestern Louisiana. Linkage and linkage disequilibrium analyses localize USH1C to chromosome 11p between markers D11S1397 and D11S1888, an interval of less than 680 kb. Here, we refine the USH1C linkage to a region less than 400 kb, between genetic markers D11S1397 and D11S1890. Using 17 genetic markers from this interval, we have isolated a contiguous set of 60 bacterial artificial chromosomes (BACs) that span the USH1C critical region. Exon trapping of BAC clones from this region resulted in the recovery of an exon of the nuclear EF-hand acidic (NEFA) gene. However, DNA sequence analysis of the NEFA cDNA from lymphocytes of affected individuals provided no evidence of mutation, making structural mutations in the NEFA protein unlikely as the cellular cause of Acadian Usher syndrome.
PubMed ID
9639681 View in PubMed
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The basis of prostaglandin synthesis in coral: molecular cloning and expression of a cyclooxygenase from the Arctic soft coral Gersemia fruticosa.

https://arctichealth.org/en/permalink/ahliterature3964
Source
J Biol Chem. 2001 Mar 9;276(10):7033-40
Publication Type
Article
Date
Mar-9-2001
Author
R. Koljak
I. Järving
R. Kurg
W E Boeglin
K. Varvas
K. Valmsen
M. Ustav
A R Brash
N. Samel
Author Affiliation
Department of Bioorganic Chemistry, Institute of Chemistry, Tallinn Technical University, Akadeemia tee 15, Tallinn 12618, Estonia.
Source
J Biol Chem. 2001 Mar 9;276(10):7033-40
Date
Mar-9-2001
Language
English
Publication Type
Article
Keywords
Alanine - chemistry
Amino Acid Sequence
Animals
Arginine - chemistry
Blotting, Northern
COS Cells
Chromatography, Thin Layer
Cloning, Molecular
Cnidaria - metabolism
Cyclooxygenase 1
Cyclooxygenase 2
DNA, Complementary - metabolism
Hela Cells
Histidine - chemistry
Humans
Isoenzymes - chemistry
Isoleucine - chemistry
Membrane Proteins
Microscopy, Fluorescence
Models, Genetic
Molecular Sequence Data
Phylogeny
Plasmids - metabolism
Polymerase Chain Reaction
Prostaglandin-Endoperoxide Synthases - biosynthesis - chemistry - genetics
Prostaglandins - biosynthesis
Protein Binding
RNA, Messenger - metabolism
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.
Sequence Analysis, DNA
Sequence Homology, Amino Acid
Serine - chemistry
Tyrosine - chemistry
Abstract
In vertebrates, the synthesis of prostaglandin hormones is catalyzed by cyclooxygenase (COX)-1, a constitutively expressed enzyme with physiological functions, and COX-2, induced in inflammation and cancer. Prostaglandins have been detected in high concentrations in certain corals, and previous evidence suggested their biosynthesis through a lipoxygenase-allene oxide pathway. Here we describe the discovery of an ancestor of cyclooxygenases that is responsible for prostaglandin biosynthesis in coral. Using a homology-based polymerase chain reaction cloning strategy, the cDNA encoding a polypeptide with approximately 50% amino acid identity to both mammalian COX-1 and COX-2 was cloned and sequenced from the Arctic soft coral Gersemia fruticosa. Nearly all the amino acids essential for substrate binding and catalysis as determined in the mammalian enzymes are represented in coral COX: the arachidonate-binding Arg(120) and Tyr(355) are present, as are the heme-coordinating His(207) and His(388); the catalytic Tyr(385); and the target of aspirin attack, Ser(530). A key amino acid that determines the sensitivity to selective COX-2 inhibitors (Ile(523) in COX-1 and Val(523) in COX-2) is present in coral COX as isoleucine. The conserved Glu(524), implicated in the binding of certain COX inhibitors, is represented as alanine. Expression of the G. fruticosa cDNA afforded a functional cyclooxygenase that converted exogenous arachidonic acid to prostaglandins. The biosynthesis was inhibited by indomethacin, whereas the selective COX-2 inhibitor nimesulide was ineffective. We conclude that the cyclooxygenase occurs widely in the animal kingdom and that vertebrate COX-1 and COX-2 are evolutionary derivatives of the invertebrate precursor.
PubMed ID
11085996 View in PubMed
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125 records – page 1 of 13.