The Reduced Level of Inorganic Polyphosphate Mobilizes Antioxidant and Manganese-Resistance Systems in .

Inorganic polyphosphate (polyP) is crucial for adaptive reactions and stress response in microorganisms. A convenient model to study the role of polyP in yeast is the strain CRN/PPN1 that overexpresses polyphosphatase Ppn1 with stably decreased polyphosphate level. In this study, we combined the whole-transcriptome sequencing, fluorescence microscopy, and polyP quantification to characterize the CRN/PPN1 response to manganese and oxidative stresses.

svist4get: a simple visualization tool for genomic tracks from sequencing experiments.

Background: High-throughput sequencing often provides a foundation for experimental analyses in the life sciences. For many such methods, an intermediate layer of bioinformatics data analysis is the genomic signal track constructed by short read mapping to a particular genome assembly. There are many software tools to visualize genomic tracks in a web browser or with a stand-alone graphical user interface.

Translatome and transcriptome analysis of TMA20 (MCT-1) and TMA64 (eIF2D) knockout yeast strains.

TMA20 (MCT-1), TMA22 (DENR) and TMA64 (eIF2D) are eukaryotic translation factors involved in ribosome recycling and re-initiation. They operate with P-site bound tRNA in post-termination or (re-)initiation translation complexes, thus participating in the removal of 40S ribosomal subunit from mRNA stop codons after termination and controlling translation re-initiation on mRNAs with upstream open reading frames (uORFs), as well as initiation on some specific mRNAs. Here we report ribosomal profiling data of strains with individual deletions of , or both and genes.

An update to database TraVA: organ-specific cold stress response in Arabidopsis thaliana.

Background: Transcriptome map is a powerful tool for a variety of biological studies; transcriptome maps that include different organs, tissues, cells and stages of development are currently available for at least 30 plants. Some of them include samples treated by environmental or biotic stresses. However, most studies explore only limited set of organs and developmental stages (leaves or seedlings).

CpG traffic lights are markers of regulatory regions in human genome.

Background: DNA methylation is involved in the regulation of gene expression. Although bisulfite-sequencing based methods profile DNA methylation at a single CpG resolution, methylation levels are usually averaged over genomic regions in the downstream bioinformatic analysis.

Results: We demonstrate that on the genome level a single CpG methylation can serve as a more accurate predictor of gene expression than an average promoter / gene body methylation.

Mask-based approach to phasing of single-particle diffraction data. II. Likelihood-based selection criteria.

A new type of mask-selection criterion is suggested for mask-based phasing. In this phasing approach, a large number of connected molecular masks are randomly generated. Structure-factor phases corresponding to a trial mask are accepted as an admissible solution of the phase problem if the mask satisfies some specified selection rules that are key to success.

Should the Treatment of Amyloidosis Be Personified? Molecular Mechanism of Amyloid Formation by Aβ Peptide and Its Fragments.

Aβ and Aβ peptides are believed to be associated with Alzheimer's disease. Aggregates (plaques) of Aβ fibrils are found in the brains of humans affected with this disease. The mechanism of formation of Aβ fibrils has not been studied completely, which hinders the development of a correct strategy for therapeutic prevention of this neurodegenerative disorder.

Genome-wide map of human and mouse transcription factor binding sites aggregated from ChIP-Seq data.

Objectives: Mammalian genomics studies, especially those focusing on transcriptional regulation, require information on genomic locations of regulatory regions, particularly, transcription factor (TF) binding sites. There are plenty of published ChIP-Seq data on in vivo binding of transcription factors in different cell types and conditions. However, handling of thousands of separate data sets is often impractical and it is desirable to have a single global map of genomic regions potentially bound by a particular TF in any of studied cell types and conditions.

Search for Functional Flexible Regions in the G-protein Family: New Reading of the FoldUnfold Program.

Background: Unstructured regions in proteins can vary from several amino acid residues to a completely disordered sequence. Since such regions play an important role in the protein functioning, much attention is being paid to their prediction. Special different programs are available for this purpose; however, predictions obtained vary from protein to protein.

Sequence characteristics define trade-offs between on-target and genome-wide off-target hybridization of oligoprobes.

Off-target oligoprobe's interaction with partially complementary nucleotide sequences represents a problem for many bio-techniques. The goal of the study was to identify oligoprobe sequence characteristics that control the ratio between on-target and off-target hybridization. To understand the complex interplay between specific and genome-wide off-target (cross-hybridization) signals, we analyzed a database derived from genomic comparison hybridization experiments performed with an Affymetrix tiling array.

To Be Fibrils or To Be Nanofilms? Oligomers Are Building Blocks for Fibril and Nanofilm Formation of Fragments of Aβ Peptide.

To identify the key stages in the amyloid fibril formation we studied the aggregation of amyloidogenic fragments of Aβ peptide, Aβ(16-25), Aβ(31-40), and Aβ(33-42), using the methods of electron microscopy, X-ray analysis, mass spectrometry, and structural modeling. We have found that fragments Aβ(31-40) and Aβ(33-42) form amyloid fibrils in the shape of bundles and ribbons, while fragment Aβ(16-25) forms only nanofilms. We are the first who performed 2D reconstruction of amyloid fibrils by the Markham rotation technique on electron micrographs of negatively stained fragments of Aβ peptide.

Winner-take-all in a phase oscillator system with adaptation.

We consider a system of generalized phase oscillators with a central element and radial connections. In contrast to conventional phase oscillators of the Kuramoto type, the dynamic variables in our system include not only the phase of each oscillator but also the natural frequency of the central oscillator, and the connection strengths from the peripheral oscillators to the central oscillator. With appropriate parameter values the system demonstrates winner-take-all behavior in terms of the competition between peripheral oscillators for the synchronization with the central oscillator.

Signaling ammonium across membranes through an ammonium sensor histidine kinase.

Sensing and uptake of external ammonium is essential for anaerobic ammonium-oxidizing (anammox) bacteria, and is typically the domain of the ubiquitous Amt/Rh ammonium transporters. Here, we report on the structure and function of an ammonium sensor/transducer from the anammox bacterium "Candidatus Kuenenia stuttgartiensis" that combines a membrane-integral ammonium transporter domain with a fused histidine kinase. It contains a high-affinity ammonium binding site not present in assimilatory Amt proteins.

Comparative mechanical unfolding studies of spectrin domains R15, R16 and R17.

Spectrins belong to repetitive three-helix bundle proteins that have vital functions in multicellular organisms and are of potential value in nanotechnology. To reveal the unique physical features of repeat proteins we have studied the structural and mechanical properties of three repeats of chicken brain α-spectrin (R15, R16 and R17) at the atomic level under stretching at constant velocities (0.01, 0.

Studying the role of axon fasciculation during development in a computational model of the Xenopus tadpole spinal cord.

During nervous system development growing axons can interact with each other, for example by adhering together in order to produce bundles (fasciculation). How does such axon-axon interaction affect the resulting axonal trajectories, and what are the possible benefits of this process in terms of network function? In this paper we study these questions by adapting an existing computational model of the development of neurons in the Xenopus tadpole spinal cord to include interactions between axons. We demonstrate that even relatively weak attraction causes bundles to appear, while if axons weakly repulse each other their trajectories diverge such that they fill the available space.

The nucleoid protein Dps binds genomic DNA of Escherichia coli in a non-random manner.

Dps is a multifunctional homododecameric protein that oxidizes Fe2+ ions accumulating them in the form of Fe2O3 within its protein cavity, interacts with DNA tightly condensing bacterial nucleoid upon starvation and performs some other functions. During the last two decades from discovery of this protein, its ferroxidase activity became rather well studied, but the mechanism of Dps interaction with DNA still remains enigmatic. The crucial role of lysine residues in the unstructured N-terminal tails led to the conventional point of view that Dps binds DNA without sequence or structural specificity.

To swim or not to swim: A population-level model of Xenopus tadpole decision making and locomotor behaviour.

We present a detailed computational model of interacting neuronal populations that mimic the hatchling Xenopus tadpole nervous system. The model includes four sensory pathways, integrators of sensory information, and a central pattern generator (CPG) network. Sensory pathways of different modalities receive inputs from an "environment"; these inputs are then processed and integrated to select the most appropriate locomotor action.

Advanced correlation grid: Analysis and visualisation of functional connectivity among multiple spike trains.

Background: This study analyses multiple spike trains (MST) data, defines its functional connectivity and subsequently visualises an accurate diagram of connections. This is a challenging problem. For example, it is difficult to distinguish the common input and the direct functional connection of two spike trains.

A Network Model of Local Field Potential Activity in Essential Tremor and the Impact of Deep Brain Stimulation.

Essential tremor (ET), a movement disorder characterised by an uncontrollable shaking of the affected body part, is often professed to be the most common movement disorder, affecting up to one percent of adults over 40 years of age. The precise cause of ET is unknown, however pathological oscillations of a network of a number of brain regions are implicated in leading to the disorder. Deep brain stimulation (DBS) is a clinical therapy used to alleviate the symptoms of a number of movement disorders.

Reaction times in visual search can be explained by a simple model of neural synchronization.

We present an oscillatory neural network model that can account for reaction times in visual search experiments. The model consists of a central oscillator that represents the central executive of the attention system and a number of peripheral oscillators that represent objects in the display. The oscillators are described as generalized Kuramoto type oscillators with adapted parameters.

Dataset of the molecular dynamics simulations of bilayers consisting of short amyloidogenic peptide VDSWNVLVAG from Bgl2p-glucantransferase of cell wall.

The amyloidogenic peptide VSWNVLVAG from Bgl2p-glucantransferase of cell wall and its modifying analog VSWNVLVAG were taken for the construction of four types of bilayers which differ by orientation of the peptides in the layers and of the layers relative to each other. These bilayers were used as starting models for the molecular dynamics (MD) at three charge states (neutral, pH3, and pH5). The changes of the fraction of secondary structure during 1 ns simulations were received for 96 MD trajectories.

Structural model of amyloid fibrils for amyloidogenic peptide from Bgl2p-glucantransferase of S. cerevisiae cell wall and its modifying analog. New morphology of amyloid fibrils.

We performed a comparative study of the process of amyloid formation by short homologous peptides with a substitution of aspartate for glutamate in position 2 - VDSWNVLVAG (AspNB) and VESWNVLVAG (GluNB) - with unblocked termini. Peptide AspNB (residues 166-175) corresponded to the predicted amyloidogenic region of the protein glucantransferase Bgl2 from the Saccharomyces cerevisiae cell wall. The process of amyloid formation was monitored by fluorescence spectroscopy (FS), electron microscopy (EM), tandem mass spectrometry (TMS), and X-ray diffraction (XD) methods.