TY - JOUR
A1 - Kreft, Jürgen
A1 - Burger, Klaus J.
A1 - Goebel, Werner
T1 - Expression of antibiotic resistance genes from Escherichia coli in Bacillus subtilis
N2 - Bifunctional recombinant plasmids were constructed, comprised of the E. coli vectors pBR322, pBR325 and pACYC184 and different plasmids from Gram-positive bacteria, e.g. pBSU161-1 of B. subtilis and pUB110 and pC221 of S. aureus. The beta-lactamase (bla) gene and the chloramphenicol acetyltransferase (cat) gene from the E. coli plasmids were not transcribed and therefore not expressed in B. subtilis. However, tetracycline resistance from the E. coli plasmids was expressed in B. subtilis. Transcription of the tetracycline resistance gene(s) started in B. subtilis at or near the original E. coli promoter, the sequence of which is almost identical with the sequence recognized by σ55 of B. subtilis RNA polymerase.
KW - Biologie
Y1 - 1983
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60600
ER -
TY - JOUR
A1 - Kreft, Jürgen
A1 - Funke, Dorothee
A1 - Haas, Albert
A1 - Lottspeich, Friedrich
A1 - Goebel, Werner
T1 - Production, purification and characterization of hemolysins from Listeria ivanovii and Listeria monocytogenes Sv4b.
N2 - In culture supematants of both Listeria ivanovii and Listeria monocytogenes Sv4b, for the first time a hemolysin of molecular weight 58 kDa was identified, which had all the characteristics of an SH-activated cytolysin, and which was therefore identified as Iisteriolysin 0 (LLO). In the case of L. ivanovii a second major supematant protein of molecular weight 24 kDa co-purified with LLO. However, the function of this protein has to be determined. In culture supematants of L. ivanovii a sphingomyelinase and a Iecithinase activity could be detected, both enzymatic activities together contributing to the pronounced hemolysis caused by L. ivanovii. The N-tenninal amino acid sequences of LLO and the 24 kDa from L. ivanovii are shown.
KW - Biologie
KW - Hemolysin
KW - Listeria
Y1 - 1989
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60545
ER -
TY - JOUR
A1 - Lampidis, Robert
A1 - Gross, Roy
A1 - Sokolovic, Zeljka
A1 - Goebel, Werner
A1 - Kreft, Jürgen
T1 - The virulence regulator protein of Listeria ivanovii is highly homologous to PrfA from Listeria monocytogenes and both belong to the Crp-Fnr family of transcription regulators
N2 - No abstract available
KW - Biologie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60503
ER -
TY - JOUR
A1 - Linsenmair, Karl Eduard
T1 - Anemomenotactic orientation in beetles and scorpions
N2 - Scorpions, living in North African semideserts are - in spite of disrupting experimental interferences - able to maintain a certain direction in their natural environment in the dark on a plane surface. Under comparable laboratory conditions, excluding the possibility of light or gravity orientation, they can orient themselves if a directed air current passes over the "arena." In most cases the scorpions do not run necessarily with or against the wind, but rather maintain constant angles to the air current for anywhere from minutes to many hours. They are running anemomenotactically (ref. 1). Under identical conditions many species of beetles also orient themselves to air currents (refs. 2 to 4). The main problems to be solved in the study of anemomenotactic orientation are: (1) Which physical qualities of the air current have an influence on the anemomenotaxis? (2) With which sense organs do beetles and scorpions perceive wind directions? (3) Which physiological mechanism is the basis of anemomenotactic orientation? (4) What is the biological significance of anemomenotaxis in beetles and scorpions? With respect to these problems, more study has been done on beetles than on scorpions. Therefore, due to lack of space, I shall discuss mainly some of the results obtained in experiments with dung beetles (Geotrupes silvaticus, G. ,Stercorarius, G. armifrons, G. niger, Scarabaeus variolosus) and tenebrionid beetles (Tenebrio molitor, Pimelia grossa, P. tenuicomis, Scaurus dubius).
KW - Biologie
KW - Skorpion
KW - Käfer
Y1 - 1972
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-78118
ER -
TY - JOUR
A1 - Linsenmair, Karl Eduard
A1 - Schmuck, R.
T1 - Adaptations of the reed frog Hyperbolius viridiflavus to its arid environment. III. Aspects of nitrogen metabolism and osmuregulation in the reed frog, H. viridiflavus taeniatus, with special reference to the role of iridophores
N2 - Reed frogs of the superspecies Hyperolius viridiflavus occur throughout the seasonally very dry and hot African savannas. Despite their small size (300-700 mg), estivating reed frogs do not avoid stressful conditions above ground by burrowing into the soil, but endure the inhospitable climate relatively unprotected, clinging to mostly dry grass sterns. They must have emcient mechanisms to enable them to survive e.g. very high temperatures, low relative hurnidities, and high solar radiation loads. Mechanisms must also have developed to prevent poisoning by the nitrogenous wastes that inevitably result from protein and nucleotide turnover. In contrast to fossorial amphibians, estivating reed frogs do not become torpid. Reduction in metabolism is therefore rather Iimited so that nitrogenous wastes accumulate faster in these frogs than in fossorial amphibians. This severely aggravates the osmotic problems caused by dehydration. During dry periods total plasma osmolarity greatly increases, mainly due to urea accumulation. Of the total urea accumulated over 42 days of experimental water deprivation, 30% was produced during the first 7 days. In the next 7 days rise in plasma urea content was negligible. This strong initial increase of urea is seen as a byproduct of elevated amino acid catabolism following the onset of dry conditions. Tbe rise in total plasma osmolarity due to urea accumulation, however, is not totally disadvantageous, but enables fast rehydration when water is available for very short periods only. Voiding of urine and feces eeases once evaporative water loss exceeds 10% of body weight. Tberefore, during continuous water deprivation, nitrogenous end products are not excreted. After 42 days of water deprivation, bladder fluid was substantially depleted, and urea coneentration in the remaining urine (up to 447 mM) was never greater than in plasma fluid. Feces voided at the end of the dry period after water uptake contained only small amounts of nitrogenous end products. DSF (dry season frogs) seemed not to be uricotelic. Instead, up to 35% of the total nitrogenous wastes produced over 42 days of water deprivation were deposited in an osmotically inert and nontoxic form in iridophore crystals. The increase in skin purine content averaged 150 µg/mg dry weight. If urea had been the only nitrogenous waste product during an estivation period of 42 days, lethal limits of total osmolarity (about 700 mOsm) would have been reached 10-14 days earlier. Thus iridophores are not only involved in colour change and in reducing heat load by radiation remission, but are also important in osmoregulation during dry periods. The seIective advantages of deposition of guanine rather than uric acid are discussed.
KW - Biologie
KW - Zoologie
KW - Frosch
KW - Hyperolius viridiflavus
KW - Estivation
KW - Osmoregulation
KW - Nitrogen metabolism
KW - lridophores
Y1 - 1988
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-78108
ER -
TY - JOUR
A1 - Menescal, Luciana
A1 - Schmidt, Cornelia
A1 - Liedtke, Daniel
A1 - Schartl, Manfred
T1 - Liver hyperplasia after tamoxifen induction of Myc in a transgenic medaka model
N2 - Myc is a global transcriptional regulator and one of the most frequently overexpressed oncoproteins in human tumors. It is well established that activation of Myc leads to enhanced cell proliferation but can also lead to increased apoptosis. The use of animal models expressing deregulated levels of Myc has helped to both elucidate its function in normal cells and give insight into how Myc initiates and maintains tumorigenesis. Analyses of the medaka (Oryzias latipes) genome uncovered the unexpected presence of two Myc gene copies in this teleost species. Comparison of these Myc versions to other vertebrate species revealed that one gene, myc17, differs by the loss of some conserved regulatory protein motifs present in all other known Myc genes. To investigate how such differences might affect the basic biological functions of Myc, we generated a tamoxifeninducible in vivo model utilizing a natural, fish-specific Myc gene. Using this model we show that, when activated, Myc17 leads to increased proliferation and to apoptosis in a dose-dependent manner, similar to human Myc. We have also shown that long-term Myc17 activation triggers liver hyperplasia in adult fish, allowing this newly established transgenic medaka model to be used to study the transition from hyperplasia to liver cancer and to identify Myc-induced tumorigenesis modifiers.
KW - Biologie
Y1 - 2012
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-75316
ER -
TY - JOUR
A1 - Prusty, Bhupesh K.
A1 - Böhme, Linda
A1 - Bergmann, Birgit
A1 - Siegl, Christine
A1 - Krause, Eva
A1 - Mehlitz, Adrian
A1 - Rudel, Thomas
T1 - Imbalanced oxidative stress causes chlamydial persistence during non-productive Human Herpes Virus co-infection
N2 - Both human herpes viruses and Chlamydia are highly prevalent in the human population and are detected together in different human disorders. Here, we demonstrate that co-infection with human herpes virus 6 (HHV6) interferes with the developmental cycle of C. trachomatis and induces persistence. Induction of chlamydial persistence by HHV6 is independent of productive virus infection, but requires the interaction and uptake of the virus by the host cell. On the other hand, viral uptake is strongly promoted under co-infection conditions. Host cell glutathione reductase activity was suppressed by HHV6 causing NADPH accumulation, decreased formation of reduced glutathione and increased oxidative stress. Prevention of oxidative stress restored infectivity of Chlamydia after HHV6-induced persistence. We show that co-infection with Herpes simplex virus 1 or human Cytomegalovirus also induces chlamydial persistence by a similar mechanism suggesting that Chlamydia -human herpes virus co-infections are evolutionary shaped interactions with a thus far unrecognized broad significance.
KW - Biologie
Y1 - 2012
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-76215
ER -
TY - JOUR
A1 - Ratzka, Carolin
A1 - Förster, Frank
A1 - Liang, Chunguang
A1 - Kupper, Maria
A1 - Dandekar, Thomas
A1 - Feldhaar, Heike
A1 - Gross, Roy
T1 - Molecular characterization of antimicrobial peptide genes of the carpenter ant Camponotus floridanus
N2 - The production of antimicrobial peptides (AMPs) is a major defense mechanism against pathogen infestation and of particular importance for insects relying exclusively on an innate immune system. Here, we report on the characterization of three AMPs from the carpenter ant Camponotus floridanus. Due to sequence similarities and amino acid composition these peptides can be classified into the cysteine-rich (e.g. defensin) and glycine-rich (e.g. hymenoptaecin) AMP groups, respectively. The gene and cDNA sequences of these AMPs were established and their expression was shown to be induced by microbial challenge. We characterized two different defensin genes. The defensin-2 gene has a single intron, whereas the defensin-1 gene has two introns. The deduced amino acid sequence of the C. floridanus defensins is very similar to other known ant defensins with the exception of a short C-terminal extension of defensin-1. The hymenoptaecin gene has a single intron and a very peculiar domain structure. The corresponding precursor protein consists of a signal- and a pro-sequence followed by a hymenoptaecin-like domain and six directly repeated hymenoptaecin domains. Each of the hymenoptaecin domains is flanked by an EAEP-spacer sequence and a RR-site known to be a proteolytic processing site. Thus, proteolytic processing of the multipeptide precursor may generate several mature AMPs leading to an amplification of the immune response. Bioinformatical analyses revealed the presence of hymenoptaecin genes with similar multipeptide precursor structure in genomes of other ant species suggesting an evolutionary conserved important role of this gene in ant immunity.
KW - Biologie
KW - Camponotus floridanus
Y1 - 2012
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-75985
ER -
TY - JOUR
A1 - Riedel, Alice
A1 - Mofolo, Boitumelo
A1 - Avota, Elita
A1 - Schneider-Schaulies, Sibylle
A1 - Meintjes, Ayton
A1 - Mulder, Nicola
A1 - Kneitz, Susanne
T1 - Accumulation of Splice Variants and Transcripts in Response to PI3K Inhibition in T Cells
N2 - Background: Measles virus (MV) causes T cell suppression by interference with phosphatidylinositol-3-kinase (PI3K) activation. We previously found that this interference affected the activity of splice regulatory proteins and a T cell inhibitory protein isoform was produced from an alternatively spliced pre-mRNA. Hypothesis: Differentially regulated and alternatively splice variant transcripts accumulating in response to PI3K abrogation in T cells potentially encode proteins involved in T cell silencing. Methods: To test this hypothesis at the cellular level, we performed a Human Exon 1.0 ST Array on RNAs isolated from T cells stimulated only or stimulated after PI3K inhibition. We developed a simple algorithm based on a splicing index to detect genes that undergo alternative splicing (AS) or are differentially regulated (RG) upon T cell suppression. Results: Applying our algorithm to the data, 9% of the genes were assigned as AS, while only 3% were attributed to RG. Though there are overlaps, AS and RG genes differed with regard to functional regulation, and were found to be enriched in different functional groups. AS genes targeted extracellular matrix (ECM)-receptor interaction and focal adhesion pathways, while RG genes were mainly enriched in cytokine-receptor interaction and Jak-STAT. When combined, AS/RG dependent alterations targeted pathways essential for T cell receptor signaling, cytoskeletal dynamics and cell cycle entry. Conclusions: PI3K abrogation interferes with key T cell activation processes through both differential expression and alternative splicing, which together actively contribute to T cell suppression.
KW - Biologie
Y1 - 2013
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-77917
ER -
TY - THES
A1 - Sauerwein, Till
T1 - Implementation and application of bioinformatical software for the analysis of dual RNA sequencing data of host and pathogen during infection
T1 - Implementierung und Anwendung bioinformatischer Software für die Analyse von dual RNA-Sequenzierdaten von Wirt und Erreger während Infektion
N2 - Since the advent of high-throughput sequencing technologies in the mid-2010s, RNA se-
quencing (RNA-seq) has been established as the method of choice for studying gene
expression. In comparison to microarray-based methods, which have mainly been used to
study gene expression before the rise of RNA-seq, RNA-seq is able to profile the entire
transcriptome of an organism without the need to predefine genes of interest. Today,
a wide variety of RNA-seq methods and protocols exist, including dual RNA sequenc-
ing (dual RNA-seq) and multi RNA sequencing (multi RNA-seq). Dual RNA-seq and
multi RNA-seq simultaneously investigate the transcriptomes of two or more species, re-
spectively. Therefore, the total RNA of all interacting species is sequenced together and
only separated in silico. Compared to conventional RNA-seq, which can only investi-
gate one species at a time, dual RNA-seq and multi RNA-seq analyses can connect the
transcriptome changes of the species being investigated and thus give a clearer picture of
the interspecies interactions. Dual RNA-seq and multi RNA-seq have been applied to a
variety of host-pathogen, mutualistic and commensal interaction systems.
We applied dual RNA-seq to a host-pathogen system of human mast cells and Staphylo-
coccus aureus (S. aureus). S. aureus, a commensal gram-positive bacterium, can become
an opportunistic pathogen and infect skin lesions of atopic dermatitis (AD) patients.
Among the first immune cells S. aureus encounters are mast cells, which have previously
been shown to be able to kill the bacteria by discharging antimicrobial products and re-
leasing extracellular traps made of protein and deoxyribonucleic acid (DNA). However,
S. aureus is known to evade the host’s immune response by internalizing within mast
cells. Our dual RNA-seq analysis of different infection settings revealed that mast cells
and S. aureus need physical contact to influence each other’s gene expression. We could
show that S. aureus cells internalizing within mast cells undergo profound transcriptome
changes to adjust their metabolism to survive in the intracellular niche. On the host side,
we found out that infected mast cells elicit a type-I interferon (IFN-I) response in an
autocrine manner and in a paracrine manner to non-infected bystander-cells. Our study
provides the first evidence that mast cells are capable to produce IFN-I upon infection
with a bacterial pathogen.
N2 - Seit dem Aufkommen von Hochdurchsatz-Sequenziertechnologien Mitte der 2010er Jahre
hat sich RNA-Sequenzierung (RNA-seq) als Methode der Wahl für die Untersuchung von
Genexpression etabliert. Im Vergleich zu Microarray-basierten Methoden, die vor dem
Aufkommen von RNA-seq hauptsächlich zur Untersuchung der Genexpression verwendet
wurden, kann mit RNA-seq das gesamte Transkriptom eines Organismus charakterisiert
werden, ohne dass die Gene von Interesse vorab definiert werden müssen. Heute gibt es ei-
ne Vielzahl von RNA-seq-Methoden und Protokollen, darunter Dual RNA-seq und Multi
RNA-seq. Dual RNA-seq und Multi RNA-seq untersuchen gleichzeitig die Transkriptome
von zwei bzw. mehreren Arten. Dazu wird die gesamte RNA aller interagierenden Arten
gemeinsam sequenziert und nur in silico aufgetrennt. Im Vergleich zur herkömmlichen
RNA-seq, bei der jeweils nur eine Spezies untersucht wird, können Dual RNA-seq- und
Multi RNA-seq-Analysen die Transkriptomveränderungen der untersuchten Spezies mit-
einander in Verbindung bringen und so ein klareres Bild der Wechselwirkungen zwischen
den Spezies vermitteln. Dual RNA-seq und Multi RNA-seq wurden bereits auf eine Viel-
zahl von Wirt-Pathogen-, mutualistischen und kommensalen Interaktionssystemen ange-
wendet.
Wir haben Dual RNA-seq auf ein Wirt-Pathogen-System aus menschlichen Mastzellen und
S. aureus angewendet. S. aureus, ein kommensales grampositives Bakterium, kann zu ei-
nem opportunistischen Erreger werden und Hautläsionen von Patienten mit atopischer
Dermatitis (AD) infizieren. Zu den ersten Immunzellen, auf die S. aureus trifft, gehören
Mastzellen, die nachweislich in der Lage sind, das Bakterium abzutöten, indem sie antimi-
krobielle Produkte abgeben und extrazelluläre Fallen aus Proteinen und DNA freisetzen.
Es ist jedoch bekannt, dass S. aureus die Immunantwort des Wirts umgehen kann, indem
es in die Mastzellen internalisiert wird. Unsere Dual RNA-seq-Analyse verschiedener In-
fektionssituationen ergab, dass Mastzellen und S. aureus physischen Kontakt benötigen,
um ihre Genexpression gegenseitig zu beeinflussen. Wir konnten zeigen, dass S. aureus
Zellen, die von Mastzellen internalisiert werden, tiefgreifende Transkriptomveränderungen
durchlaufen, um ihren Stoffwechsel für das ̈Uberleben in der intrazellulären Nische an-
zupassen. Auf Seite des Wirts fanden wir heraus, dass infizierte Mastzellen eine IFN-I
(Interferon Typ I)-Antwort auf autokrine und auf parakrine Weise auf nicht-infizierte, in
der Nähe befindliche Zellen auslösen. Unsere Studie liefert den ersten Beweis dafür, dass
Mastzellen bei einer Infektion mit einem bakteriellen Erreger in der Lage sind, IFN-I zu
produzieren.
Um die bioinformatische Analyse von Dual RNA-seq und Multi RNA-seq zu erleichtern,
haben wir ein umfangreiches Update des bereits existierenden RNA-seq-Analysepro-
gramms READemption veröffentlicht. Die neue Version READemption 2 ermöglicht es
den Nutzern, Dual RNA-seq- und Multi RNA-seq-Daten einer beliebigen Anzahl von Spe-
zies auf bequeme Weise zu analysieren, während es weiterhin möglich ist, herkömmliche
RNA-seq-Projekte zu analysieren, die nur eine Spezies untersuchen. Bei der Entwicklung
wurde Wert darauf gelegt, die Qualität der Software durch die Einhaltung bewährter
Verfahren für die Entwicklung wissenschaftlicher Software hoch zu halten.
KW - Biologie
KW - biology
Y1 - 2023
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-303075
ER -
TY - JOUR
A1 - Schartl, Manfred
A1 - Kneitz, Susanne
A1 - Wilde, Brigitta
A1 - Wagner, Toni
A1 - Henkel, Christiaan V.
A1 - Spaink, Hermann P.
A1 - Meierjohann, Svenja
T1 - Conserved expression signatures between medaka and human pigment cell tumors
N2 - Aberrations in gene expression are a hallmark of cancer cells. Differential tumor-specific transcript levels of single genes or whole sets of genes may be critical for the neoplastic phenotype and important for therapeutic considerations or useful as biomarkers. As an approach to filter out such relevant expression differences from the plethora of changes noted in global expression profiling studies, we searched for changes of gene expression levels that are conserved. Transcriptomes from massive parallel sequencing of different types of melanoma from medaka were generated and compared to microarray datasets from zebrafish and human melanoma. This revealed molecular conservation at various levels between fish models and human tumors providing a useful strategy for identifying expression signatures strongly associated with disease phenotypes and uncovering new melanoma molecules.
KW - Biologie
Y1 - 2012
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-75848
ER -
TY - JOUR
A1 - Schmuck, R.
A1 - Kobelt, F.
A1 - Linsenmair, Karl Eduard
T1 - Adaptations of the reed frog Hyperbolius viridiflavus (Anura, Hyperbolidae) to its arid environment: V. Iridophores and nitrogen metabolism
N2 - Ofall amphibians living in arid habitats, reed frogs (belonging to the super species Hyperolius viridiflavus) are the most peculiar. Froglets are able to tolerate dry periods of up to 35 days or longer immediately after metamorphosis, in climatically exposed positions. They face similar problems to estivating juveniles, i.e. enduranee of long periods of high temperature and low RH with rather limited energy and water reserves. In addition, they must have had to develop meehanisms to prevent poisoning by nitrogenous wastes that rapidly accumulate during dry periods as a metabolie consequenee of maintaining a non-torpid state. During dry periods, plasma osmolarity of H. v. taeniatus froglets strongly increased, mainly through urea accumulation. Urea accumulation was also observed during metamorphic climax. During postmetamorphic growth, chromatophores develop with the density and morphology typical of the adult pigmentary pattern. The dermal iridophore layer, which is still incomplete at this time, is fully developed within 4-8 days after metamorphosis, irrespective of maintenance conditions. These iridophores mainly contain the purines guanine and hypoxanthine. The ability of these purines to reflect light provides an excellent basis for the role of iridophores in temperature regulation. In individuals experiencing dehydration stress, the initial rate of purine synthesis is doubled in eomparison to specimens continuously maintained under wet season conditions. This increase in synthesis rate leads to a rapid increase in the thiekness of the iridophore layer, thereby effectively reducing radiation absorption. Thus, the danger of overheating is diminished during periods of water shortage when evaporative cooling must be avoided. After the development of an iridophore layer of sufficient thickness for effective radiation reflectance, synthesis of iridophore pigments does not cease. Rather, this pathway is further used during the remaining dry season for solving osmotic problems eaused by accumulation of nitrogenous wastes. During prolonged water deprivation, in spite of reduced metabolic rates, purine pigments are produced at the same rate as in wet season conditions. This leads to a higher relative proportion of nitrogen end products being stored in skin pigments under dry season conditions. At the end of an experimental dry season lasting 35 days, up to 38% of the accrued nitrogen is stored in the form of osmotically inactive purines in thc skin. Thus the osmotic problems caused by evaporative water loss and urea production are greatly reduced.
KW - Biologie
KW - Zoologie
KW - Frosch
Y1 - 1988
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-78094
ER -
TY - JOUR
A1 - Schülein, Ralf
A1 - Kreft, Jürgen
A1 - Gonski, Sigrid
A1 - Goebel, Werner
T1 - Preprosubtilisin Carlsberg processing and secretion is blocked after deletion of amino acids 97-101 in the mature part of the enzyme
N2 - During an investigation into the substrate specificity and processing of subtilisin Carlsberg from Bacillus licheniformis, two major independent findings were made: (i) as has been shown previously, a stretch of five amino acids (residues 97-101 of the mature enzyme) that loops out into the binding cleft is involved in substrate binding by subtilisin Carlsberg. In order to see whether this loop element also determines substrate specificity, the coding region for these five amino acids was deleted from the cloned gene for subtilisin Carlsberg by site-directed mutagenesis. Unexpectedly the resulting mutant preproenzyme (P42c, Mr=42 kDa) was not processed to the mature form (Mr = 30 kDa) and was not released into the medium by a proteasedeficient B. subtilis host strain; rather, it accumulated in the cell membrane. This result demonstrates that the integrity of this loop element, which is very distant from the processing cleavage sites in the preproenzyme, is required for secretion of subtilisin Carlsberg. (ii) In culture supernatants from B. subtilis harbouring the cloned wild-type subtilisin Carlsberg gene the transient appearance (at 0-3 h after onset of stationary phase) of a processing intermediate (P38c, Mr = 38 kDa) oftbis protease could be demonstrated. P38c very probably represents a genuine proform of subtilisin Carlsberg.
KW - Biologie
KW - Bacillus
KW - Proenzyme
KW - Subtilisin maturation
KW - Site-directed mutagenesis
KW - Subtilisin Carlsberg
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60577
ER -
TY - JOUR
A1 - Sturm, Julia B.
A1 - Hess, Michael
A1 - Weibel, Stephanie
A1 - Chen, Nanhei G.
A1 - Yu, Yong A.
A1 - Zhang, Quian
A1 - Donat, Ulrike
A1 - Reiss, Cora
A1 - Gambaryan, Stepan
A1 - Krohne, Georg
A1 - Stritzker, Jochen
A1 - Szalay, Aladar A.
T1 - Functional hyper-IL-6 from vaccinia virus-colonized tumors triggers platelet formation and helps to alleviate toxicity of mitomycin C enhanced virus therapy
N2 - Background: Combination of oncolytic vaccinia virus therapy with conventional chemotherapy has shown promise for tumor therapy. However, side effects of chemotherapy including thrombocytopenia, still remain problematic. Methods: Here, we describe a novel approach to optimize combination therapy of oncolytic virus and chemotherapy utilizing virus-encoding hyper-IL-6, GLV-1h90, to reduce chemotherapy-associated side effects. Results: We showed that the hyper-IL-6 cytokine was successfully produced by GLV-1h90 and was functional both in cell culture as well as in tumor-bearing animals, in which the cytokine-producing vaccinia virus strain was well tolerated. When combined with the chemotherapeutic mitomycin C, the anti-tumor effect of the oncolytic virotherapy was significantly enhanced. Moreover, hyper-IL-6 expression greatly reduced the time interval during which the mice suffered from chemotherapy-induced thrombocytopenia. Conclusion: Therefore, future clinical application would benefit from careful investigation of additional cytokine treatment to reduce chemotherapy-induced side effects.
KW - Biologie
KW - vaccinia virus
KW - cancer
KW - cytokine
KW - hyper-IL-6
KW - oncolysis
KW - chemotherapy
Y1 - 2012
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-75224
ER -