Dikicioglu D.,Bogazici University |
Karabekmez E.,Bogazici University |
Rash B.,University of Manchester |
Pir P.,University of Cambridge |
And 4 more authors.
BMC Systems Biology
Background: A microorganism is able to adapt to changes in its physicochemical or nutritional environment and this is crucial for its survival. The yeast, Saccharomyces cerevisiae, has developed mechanisms to respond to such environmental changes in a rapid and effective manner; such responses may demand a widespread re-programming of gene activity. The dynamics of the re-organization of the cellular activities of S. cerevisiae in response to the sudden and transient removal of either carbon or nitrogen limitation has been studied by following both the short- and long-term changes in yeast's transcriptomic profiles.Results: The study, which spans timescales from seconds to hours, has revealed the hierarchy of metabolic and genetic regulatory switches that allow yeast to adapt to, and recover from, a pulse of a previously limiting nutrient. At the transcriptome level, a glucose impulse evoked significant changes in the expression of genes concerned with glycolysis, carboxylic acid metabolism, oxidative phosphorylation, and nucleic acid and sulphur metabolism. In ammonium-limited cultures, an ammonium impulse resulted in the significant changes in the expression of genes involved in nitrogen metabolism and ion transport. Although both perturbations evoked significant changes in the expression of genes involved in the machinery and process of protein synthesis, the transcriptomic response was delayed and less complex in the case of an ammonium impulse. Analysis of the regulatory events by two different system-level, network-based approaches provided further information about dynamic organization of yeast cells as a response to a nutritional change.Conclusions: The study provided important information on the temporal organization of transcriptomic organization and underlying regulatory events as a response to both carbon and nitrogen impulse. It has also revealed the importance of a long-term dynamic analysis of the response to the relaxation of a nutritional limitation to understand the molecular basis of the cells' dynamic behaviour. © 2011 Dikicioglu et al; licensee BioMed Central Ltd. Source
Novacta Biosystems | Date: 2011-06-10
This invention relates to characterisation of the biosynthetic gene cluster for the lantibiotic actagardine, identification of a novel variant of actagardine and its biosynthetic cluster, and methods of production and use of actagardine, a novel actagardine variant, herein referred to as actagardine B, and variants of both of these produced according to this invention, utilizing genes from the characterised biosynthetic gene clusters.
Novacta Biosystems | Date: 2010-01-12
The present invention pertains generally to certain compounds of the deoxyactagardine A and B type. Such compounds are suitable for use in the treatment of microbial infections, for example
CANTAB ANTI INFECTIVES Ltd and Novacta Biosystems | Date: 2012-11-16
Provided are compounds, the use of the said compounds in treatment, for example treatment of microbial infections, particularly by Gram negative bacteria. The compounds are polymyxin-based and are represented by the formula (I): and pharmaceutically acceptable salts thereof, where X is NHC(O), C(O), OC(O), CH2 or SO2; R5 represents C0-12 alkyl(C4-6 heterocyclyl), or C2-12 alkyl or C0-12 alkyl(C3-8 cycloalkyl). and the alkyl or cycloalkyl bears one, two or three hydroxyl groups, or a NR6R7 group, or one NR6R7 group and one or two hydroxyl groups; and R1 to R4 and R6 to R8 are as defined in the description.
Novacta Biosystems | Date: 2011-07-12
Described is a pharmaceutical formulation of a capsule for oral delivery of a type B lantibiotic to the stomach comprising a hard gelatine, HPMC or starch capsule, and a type B lantibiotic of formula (I): wherein X is NH(CH