scholarly journals Protective effect of the T112 PrP variant in sheep challenged with bovine spongiform encephalopathy

2009 ◽  
Vol 90 (10) ◽  
pp. 2569-2574 ◽  
Author(s):  
G. C. Saunders ◽  
I. Lantier ◽  
S. Cawthraw ◽  
P. Berthon ◽  
S. J. Moore ◽  
...  
Keyword(s):  
Protective Effect ◽  
Bovine Spongiform Encephalopathy ◽  
Open Reading Frame ◽  
Spongiform Encephalopathy ◽  
Wild Type ◽  
Reading Frame ◽  
Incubation Periods ◽  
Codon Positions ◽  
Gene Open Reading Frame ◽  
Suffolk Sheep

Sheep with an ARQ/ARQ PRNP genotype at codon positions 136/154/171 are highly susceptible to experimental infection with bovine spongiform encephalopathy (BSE). However, a number of sheep challenged orally or intracerebrally with BSE were clinically asymptomatic and found to survive or were diagnosed as BSE-negative when culled. Sequencing of the full PRNP gene open reading frame of BSE-susceptible and -resistant sheep indicated that, in the majority of Suffolk sheep, resistance was associated with an M112T PRNP variant (TARQ allele). A high proportion (47 of 49; 96 %) of BSE-challenged wild-type (MARQ/MARQ) Suffolk sheep were BSE-infected, whereas none of the 20 sheep with at least one TARQ allele succumbed to BSE. Thirteen TARQ-carrying sheep challenged with BSE are still alive and some have survival periods equivalent to, or greater than, reported incubation periods of BSE in ARR/ARR and VRQ/VRQ sheep.

scholarly journals Transmissions of variant Creutzfeldt–Jakob disease from brain and lymphoreticular tissue show uniform and conserved bovine spongiform encephalopathy-related phenotypic properties on primary and secondary passage in wild-type mice

2009 ◽  
Vol 90 (12) ◽  
pp. 3075-3082 ◽  
Author(s):  
Diane L. Ritchie ◽  
Aileen Boyle ◽  
Irene McConnell ◽  
Mark W. Head ◽  
James W. Ironside ◽  
...  
Keyword(s):  
Bovine Spongiform Encephalopathy ◽  
Fragment Size ◽  
Biological Properties ◽  
Mouse Strains ◽  
Spongiform Encephalopathy ◽  
Wild Type ◽  
Phenotypic Properties ◽  
Peripheral Tissues ◽  
Incubation Periods ◽  
Jakob Disease

Prion strains are defined by their biological properties after transmission to wild-type mice, specifically by their incubation periods and patterns of vacuolar pathology (‘lesion profiles’). Preliminary results from transmissions of variant Creutzfeldt–Jakob disease (vCJD) to wild-type mice provided the first compelling evidence for the close similarity of the vCJD agent to the agent causing bovine spongiform encephalopathy (BSE). Complete results from this investigation, including the transmission characteristics of vCJD from brain and peripheral tissues of 10 cases (after primary transmission and subsequent mouse-to-mouse passage), have now been analysed. All 10 vCJD sources resulted in consistent incubation periods and lesion profiles, suggesting that all 10 patients were infected with the same strain of agent. Incubation periods suggested that infectious titres may be subject to regional variation within the brain. Comparison of incubation periods and lesion profiles from transmission of brain and peripheral tissues showed no evidence of tissue-specific modification in the biological properties of the agent. Analysis of the protease-resistant prion protein (PrPres) by Western blotting from primary and subsequent passages in mice showed a glycosylation pattern closely resembling that of vCJD in humans, the so-called BSE ‘glycoform signature’. Minor variations in PrPres fragment size were evident between mouse strains carrying different alleles of the gene encoding PrP both in primary transmissions and on further passages of vCJD brain. Overall, the results closely resembled those of previously reported transmissions of BSE in the same mouse strains, consistent with BSE being the origin of all of these vCJD cases.

scholarly journals The Cloning and Molecular Analysis of pawn-B in Paramecium tetraurelia

Genetics ◽  
2000 ◽  
Vol 155 (3) ◽  
pp. 1105-1117 ◽  
Author(s):  
W John Haynes ◽  
Kit-Yin Ling ◽  
Robin R Preston ◽  
Yoshiro Saimi ◽  
Ching Kung
Keyword(s):  
Genomic Library ◽  
Open Reading Frame ◽  
Paramecium Tetraurelia ◽  
Wild Type ◽  
Rt Pcr ◽  
Reading Frame ◽  
Close Proximity ◽  
In The Wild ◽  
Dna Fragment ◽  
Alternative Sites

Abstract Pawn mutants of Paramecium tetraurelia lack a depolarization-activated Ca2+ current and do not swim backward. Using the method of microinjection and sorting a genomic library, we have cloned a DNA fragment that complements pawn-B (pwB/pwB). The minimal complementing fragment is a 798-bp open reading frame (ORF) that restores the Ca2+ current and the backward swimming when expressed. This ORF contains a 29-bp intron and is transcribed and translated. The translated product has two putative transmembrane domains but no clear matches in current databases. Mutations in the available pwB alleles were found within this ORF. The d4-95 and d4-96 alleles are single base substitutions, while d4-662 (previously pawn-D) harbors a 44-bp insertion that matches an internal eliminated sequence (IES) found in the wild-type germline DNA except for a single C-to-T transition. Northern hybridizations and RT-PCR indicate that d4-662 transcripts are rapidly degraded or not produced. A second 155-bp IES in the wild-type germline ORF excises at two alternative sites spanning three asparagine codons. The pwB ORF appears to be separated from a 5′ neighboring ORF by only 36 bp. The close proximity of the two ORFs and the location of the pwB protein as indicated by GFP-fusion constructs are discussed.

scholarly journals CZK3, a MAP Kinase Kinase Kinase Homolog in Cercospora zeae-maydis, Regulates Cercosporin Biosynthesis, Fungal Development, and Pathogenesis

2003 ◽  
Vol 16 (9) ◽  
pp. 760-768 ◽  
Author(s):  
Won-Bo Shim ◽  
Larry D. Dunkle
Keyword(s):  
Map Kinase ◽  
Map Kinases ◽  
Gray Leaf Spot ◽  
Open Reading Frame ◽  
Wild Type ◽  
Toxic Activity ◽  
Reading Frame ◽  
Cercospora Zeae Maydis ◽  
Map Kinase Kinase Kinase ◽  
Map Kinase Kinase

The fungus Cercospora zeae-maydis causes gray leaf spot of maize and produces cercosporin, a photosensitizing perylenequinone with toxic activity against a broad spectrum of organisms. However, little is known about the biosynthetic pathway or factors that regulate cercosporin production. Analysis of a cDNA subtraction library comprised of genes that are up-regulated during cercosporin synthesis revealed a sequence highly similar to mitogen-activated protein (MAP) kinases in other fungi. Sequencing and conceptual translation of the full-length genomic sequence indicated that the gene, which we designated CZK3, contains a 4,119-bp open reading frame devoid of introns and encodes a 1,373-amino acid sequence that is highly similar to Wis4, a MAP kinase kinase kinase in Schizosaccharomyces pombe. Targeted disruption of CZK3 suppressed expression of genes predicted to participate in cercosporin biosynthesis and abolished cercosporin production. The disrupted mutants grew faster on agar media than the wild type but were deficient in conidiation and elicited only small chlorotic spots on inoculated maize leaves compared with rectangular necrotic lesions incited by the wild type. Complementation of disruptants with the CZK3 open reading frame and flanking sequences restored wild-type levels of conidiation, growth rate, and virulence as well as the ability to produce cercosporin. The results suggest that cercosporin is a virulence factor in C. zeae-maydis during maize pathogenesis, but the pleiotropic effects of CZK3 disruption precluded definitive conclusions.

Molecular and genetic analysis of the gene encoding the Saccharomyces cerevisiae strand exchange protein Sep1

1991 ◽  
Vol 11 (5) ◽  
pp. 2593-2608 ◽  
Author(s):  
D X Tishkoff ◽  
A W Johnson ◽  
R D Kolodner
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Open Reading Frame ◽  
Strand Exchange ◽  
Wild Type ◽  
Homologous Pairing ◽  
Gene Encoding ◽  
Reading Frame ◽  
Cloned Gene ◽  
Diploid Cells ◽  
Exchange Protein

Vegetatively grown Saccharomyces cerevisiae cells contain an activity that promotes a number of homologous pairing reactions. A major portion of this activity is due to strand exchange protein 1 (Sep1), which was originally purified as a 132,000-Mr species (R. Kolodner, D. H. Evans, and P. T. Morrison, Proc. Natl. Acad. Sci. USA 84:5560-5564, 1987). The gene encoding Sep1 was cloned, and analysis of the cloned gene revealed a 4,587-bp open reading frame capable of encoding a 175,000-Mr protein. The protein encoded by this open reading frame was overproduced and purified and had a relative molecular weight of approximately 160,000. The 160,000-Mr protein was at least as active in promoting homologous pairing as the original 132,000-Mr species, which has been shown to be a fragment of the intact 160,000-Mr Sep1 protein. The SEP1 gene mapped to chromosome VII within 20 kbp of RAD54. Three Tn10LUK insertion mutations in the SEP1 gene were characterized. sep1 mutants grew more slowly than wild-type cells, showed a two- to fivefold decrease in the rate of spontaneous mitotic recombination between his4 heteroalleles, and were delayed in their ability to return to growth after UV or gamma irradiation. Sporulation of sep1/sep1 diploids was defective, as indicated by both a 10- to 40-fold reduction in spore formation and reduced spore viability of approximately 50%. The majority of sep1/sep1 diploid cells arrested in meiosis after commitment to recombination but prior to the meiosis I cell division. Return-to-growth experiments showed that sep1/sep1 his4X/his4B diploids exhibited a five- to sixfold greater meiotic induction of His+ recombinants than did isogenic SEP1/SEP1 strains. sep1/sep1 mutants also showed an increased frequency of exchange between HIS4, LEU2, and MAT and a lack of positive interference between these markers compared with wild-type controls. The interaction between sep1, rad50, and spo13 mutations suggested that SEP1 acts in meiosis in a pathway that is parallel to the RAD50 pathway.

Cloning and Characterization of a Prolinase Gene (pepR) from Lactobacillus rhamnosus

1998 ◽  
Vol 64 (5) ◽  
pp. 1831-1836 ◽  
Author(s):  
Pekka Varmanen ◽  
Terhi Rantanen ◽  
Airi Palva ◽  
Soile Tynkkynen
Keyword(s):  
Lactobacillus Rhamnosus ◽  
Gene Replacement ◽  
Lactobacillus Helveticus ◽  
Open Reading Frame ◽  
Transcriptional Unit ◽  
Wild Type ◽  
Reading Frame ◽  
Gene Expressing ◽  
Produce Acid

ABSTRACT A peptidase gene expressingl-proline-β-naphthylamide-hydrolyzing activity was cloned from a gene library of Lactobacillus rhamnosus 1/6 isolated from cheese. Peptidase-expressing activity was localized in a 1.5-kbSacI fragment. A sequence analysis of the SacI fragment revealed the presence of one complete open reading frame (ORF1) that was 903 nucleotides long. The ORF1-encoded 34.2-kDa protein exhibited 68% identity with the PepR protein from Lactobacillus helveticus. Additional sequencing revealed the presence of another open reading frame (ORF2) following pepR; this open reading frame was 459 bp long. Northern (RNA) and primer extension analyses indicated that pepR is expressed both as a monocistronic transcriptional unit and as a dicistronic transcriptional unit with ORF2. Gene replacement was used to construct a PepR-negative strain of L. rhamnosus. PepR was shown to be the primary enzyme capable of hydrolyzing Pro-Leu in L. rhamnosus. However, the PepR-negative mutant did not differ from the wild type in its ability to grow and produce acid in milk. The clonedpepR expressed activity against dipeptides with N-terminal proline residues. Also, Met-Ala, Leu-Leu, and Leu-Gly-Gly and the chromogenic substrates l-leucine-β-naphthylamide andl-phenylalanine-β-naphthylamide were hydrolyzed by the PepR of L. rhamnosus.

scholarly journals Chronic wasting disease and atypical forms of bovine spongiform encephalopathy and scrapie are not transmissible to mice expressing wild-type levels of human prion protein

2012 ◽  
Vol 93 (7) ◽  
pp. 1624-1629 ◽  
Author(s):  
Rona Wilson ◽  
Chris Plinston ◽  
Nora Hunter ◽  
Cristina Casalone ◽  
Cristiano Corona ◽  
...  
Keyword(s):  
Bovine Spongiform Encephalopathy ◽  
Prion Protein ◽  
Chronic Wasting Disease ◽  
Transmissible Spongiform Encephalopathies ◽  
Spongiform Encephalopathy ◽  
Wild Type ◽  
Wasting Disease ◽  
Spongiform Encephalopathies ◽  
Jakob Disease ◽  
Human Prion Protein

The association between bovine spongiform encephalopathy (BSE) and variant Creutzfeldt–Jakob disease (vCJD) has demonstrated that cattle transmissible spongiform encephalopathies (TSEs) can pose a risk to human health and raises the possibility that other ruminant TSEs may be transmissible to humans. In recent years, several novel TSEs in sheep, cattle and deer have been described and the risk posed to humans by these agents is currently unknown. In this study, we inoculated two forms of atypical BSE (BASE and H-type BSE), a chronic wasting disease (CWD) isolate and seven isolates of atypical scrapie into gene-targeted transgenic (Tg) mice expressing the human prion protein (PrP). Upon challenge with these ruminant TSEs, gene-targeted Tg mice expressing human PrP did not show any signs of disease pathology. These data strongly suggest the presence of a substantial transmission barrier between these recently identified ruminant TSEs and humans.

scholarly journals Characterization of a gene product (Sec53p) required for protein assembly in the yeast endoplasmic reticulum.

1985 ◽  
Vol 101 (6) ◽  
pp. 2374-2382 ◽  
Author(s):  
M Bernstein ◽  
W Hoffmann ◽  
G Ammerer ◽  
R Schekman
Keyword(s):  
Endoplasmic Reticulum ◽  
Gene Fusion ◽  
Protein Assembly ◽  
Open Reading Frame ◽  
Cell Fractionation ◽  
Multicopy Plasmid ◽  
Wild Type ◽  
Cytosol Fraction ◽  
Reading Frame

SEC53, a gene that is required for completion of assembly of proteins in the endoplasmic reticulum in yeast, has been cloned, sequenced, and the product localized by cell fractionation. Complementation of a sec53 mutation is achieved with unique plasmids from genomic or cDNA expression banks. These inserts contain the authentic gene, a cloned copy of which integrates at the sec53 locus. An open reading frame in the insert predicts a 29-kD protein with no significant hydrophobic character. This prediction is confirmed by detection of a 28-kD protein overproduced in cells that carry SEC53 on a multicopy plasmid. To follow Sec53p more directly, a LacZ-SEC53 gene fusion has been constructed which allows the isolation of a hybrid protein for use in production of antibody. With such an antibody, quantitative immune decoration has shown that the sec53-6 mutation decreases the level of Sec53p at 37 degrees C, while levels comparable to wild-type are seen at 24 degrees C. An eightfold overproduction of Sec53p accompanies transformation of cells with a multicopy plasmid containing SEC53. Cell fractionation, performed with conditions that preserve the lumenal content of the endoplasmic reticulum (ER), shows Sec53p highly enriched in the cytosol fraction. We suggest that Sec53p acts indirectly to facilitate assembly in the ER, possibly by interacting with a stable ER component, or by providing a small molecule, other than an oligosaccharide precursor, necessary for the assembly event.

scholarly journals Deletion of Open Reading Frame UL26 from the Human Cytomegalovirus Genome Results in Reduced Viral Growth, Which Involves Impaired Stability of Viral Particles

2006 ◽  
Vol 80 (11) ◽  
pp. 5423-5434 ◽  
Author(s):  
Kerstin Lorz ◽  
Heike Hofmann ◽  
Anja Berndt ◽  
Nina Tavalai ◽  
Regina Mueller ◽  
...  
Keyword(s):  
Human Cytomegalovirus ◽  
Transcriptional Activation ◽  
Deletion Mutant ◽  
Artificial Chromosome ◽  
Open Reading Frame ◽  
Wild Type Virus ◽  
Wild Type ◽  
Reading Frame ◽  
Transcriptional Activation Domain ◽  
Viral Particles

ABSTRACT We previously showed that open reading frame (ORF) UL26 of human cytomegalovirus, a member of the US22 multigene family of betaherpesviruses, encodes a novel tegument protein, which is imported into cells in the course of viral infection. Moreover, we demonstrated that pUL26 contains a strong transcriptional activation domain and is capable of stimulating the major immediate-early (IE) enhancer-promoter. Since this suggested an important function of pUL26 during the initiation of the viral replicative cycle, we sought to ascertain the relevance of pUL26 by construction of a viral deletion mutant lacking the UL26 ORF using the bacterial artificial chromosome mutagenesis procedure. The resulting deletion virus was verified by PCR, enzyme restriction, and Southern blot analyses. After infection of human foreskin fibroblasts, the UL26 deletion mutant showed a small-plaque phenotype and replicated to significantly lower titers than wild-type or revertant virus. In particular, we noticed a striking decrease of infectious titers 7 days postinfection in a multistep growth experiment, whereas the release of viral DNA from infected cells was not impaired. A further investigation of this aspect revealed a significantly diminished stability of viral particles derived from the UL26 deletion mutant. Consistent with this, we observed that the tegument composition of the deletion mutant deviates from that of the wild-type virus. We therefore hypothesize that pUL26 plays a role not only in the onset of IE gene transcription but also in the assembly of the viral tegument layer in a stable and correct manner.

scholarly journals Transmission and Adaptation of Chronic Wasting Disease to Hamsters and Transgenic Mice: Evidence for Strains

2007 ◽  
Vol 81 (8) ◽  
pp. 4305-4314 ◽  
Author(s):  
Gregory J. Raymond ◽  
Lynne D. Raymond ◽  
Kimberly D. Meade-White ◽  
Andrew G. Hughson ◽  
Cynthia Favara ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Prion Protein ◽  
Chronic Wasting Disease ◽  
Transmissible Spongiform Encephalopathy ◽  
Wild Type Mouse ◽  
Mouse Strains ◽  
Spongiform Encephalopathy ◽  
Wild Type ◽  
Wasting Disease ◽  
Incubation Periods

ABSTRACT In vitro screening using the cell-free prion protein conversion system indicated that certain rodents may be susceptible to chronic wasting disease (CWD). Therefore, CWD isolates from mule deer, white-tailed deer, and elk were inoculated intracerebrally into various rodent species to assess the rodents' susceptibility and to develop new rodent models of CWD. The species inoculated were Syrian golden, Djungarian, Chinese, Siberian, and Armenian hamsters, transgenic mice expressing the Syrian golden hamster prion protein, and RML Swiss and C57BL10 wild-type mice. The transgenic mice and the Syrian golden, Chinese, Siberian, and Armenian hamsters had limited susceptibility to certain of the CWD inocula, as evidenced by incomplete attack rates and long incubation periods. For serial passages of CWD isolates in Syrian golden hamsters, incubation periods rapidly stabilized, with isolates having either short (85 to 89 days) or long (408 to 544 days) mean incubation periods and distinct neuropathological patterns. In contrast, wild-type mouse strains and Djungarian hamsters were not susceptible to CWD. These results show that CWD can be transmitted and adapted to some species of rodents and suggest that the cervid-derived CWD inocula may have contained or diverged into at least two distinct transmissible spongiform encephalopathy strains.

Increased L-Ornithine Production in Corynebacterium glutamicum by Overexpression of a Gene Encoding a Putative Aminotransferase

2015 ◽  
Vol 25 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Dai-Joong Kim ◽  
Gui-Hye Hwang ◽  
Ji-Na Um ◽  
Jae-Yong Cho
Keyword(s):  
Biosynthetic Pathway ◽  
Gene Promoter ◽  
Open Reading Frame ◽  
Aminotransferase Activity ◽  
Wild Type ◽  
Gene Encoding ◽  
Reading Frame ◽  
Dehydrogenase Gene ◽  
Putative Aminotransferase ◽  
Combined Overexpression

Overexpression of the NCgl0462 open reading frame, encoding a class II aminotransferase, was studied in conjunction with other enzymes in <smlcap>L</smlcap>-ornithine biosynthesis in an <smlcap>L</smlcap>-ornithine-producing strain. Expression of the wild-type NCgl0462 open reading frame, which displayed aminotransferase activity, was amplified by placing it under the control of the glyceraldehyde 3-phosphate dehydrogenase gene promoter in the pEK0 plasmid and in the genome. <smlcap>L</smlcap>-Ornithine production in <i>Corynebacterium</i><i>glutamicum</i> SJC8260 harboring plasmid and the genomic NCgl0462 open reading frame was increased by 8.8 and 21.6%, respectively. In addition, the combined overexpression of the NCgl0462 open reading frame within the genome along with the mutated <smlcap>L</smlcap>-ornithine biosynthesis genes <i>(argCJBD)</i> placed in the pEK0 plasmid in <i>C</i>. <i>glutamicum</i> SJC8260 resulted in significant improvement in <smlcap>L</smlcap>-ornithine production (12.48 g/l for combined overexpression compared with 8.42 g/l for the control). These results suggest that overexpression of the aminotransferase-encoding NCgl0462 open reading frame plays an unequivocal role in the <smlcap>L</smlcap>-ornithine biosynthetic pathway, with overlapping substrate specificity in <i>C</i>. <i>glutamicum</i>.

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