The cellular stress response of the scleractinian coral <Emphasis Type="Italic">Goniopora columna</Emphasis> during the progression of the black band disease

Black band disease (BBD) is a widespread coral pathology caused by a microbial consortium dominated by cyanobacteria, which is significantly contributing to the loss of coral cover and diversity worldwide. Since the effects of the BBD pathogens on the physiology and cellular stress response of coral polyps appear almost unknown, the expression of some molecular biomarkers, such as Hsp70, Hsp60, HO-1, and MnSOD, was analyzed in the apparently healthy tissues of Goniopora columna located at different distances from the infection and during two disease development stages. All the biomarkers displayed different levels of expression between healthy and diseased colonies. In the healthy corals, low basal levels were found stable over time in different parts of the same colony. On the contrary, in the diseased colonies, a strong up-regulation of all the biomarkers was observed in all the tissues surrounding the infection, which suffered an oxidative stress probably generated by the alternation, at the progression front of the disease, of conditions of oxygen supersaturation and hypoxia/anoxia, and by the production of the cyanotoxin microcystin by the BBD cyanobacteria. Furthermore, in the infected colonies, the expression of all the biomarkers appeared significantly affected by the development stage of the disease. In conclusion, our approach may constitute a useful diagnostic tool, since the cellular stress response of corals is activated before the pathogens colonize the tissues, and expands the current knowledge of the mechanisms controlling the host responses to infection in corals.     

Improved Secretion of Native Human Insulin-Like Growth Factor 1 from gas1 Mutant Saccharomyces cerevisiae Cells

We studied the secretion of recombinant human insulin-like growth factor 1 (rhIGF-1) from transformed yeast cells. The hIGF-1 gene was fused to the mating factor α prepro- leader sequence under the control of the constitutive ACT1 promoter. We found that the inactivation of the GAS1 gene in the host strain led to a supersecretory phenotype yielding a considerable increase, from 8 to 55 mg/liter, in rhIGF-1 production.     

Peripheral Visual Performance Enhancement by Neurofeedback Training

Peripheral visual performance is an important ability for everyone, and a positive inter-individual correlation is found between the peripheral visual performance and the alpha amplitude during the performance test. This study investigated the effect of alpha neurofeedback training on the peripheral visual performance. A neurofeedback group of 13 subjects finished 20 sessions of alpha enhancement feedback within 20 days. The peripheral visual performance was assessed by a new dynamic peripheral visual test on the first and last training day. The results revealed that the neurofeedback group showed significant enhancement of the peripheral visual performance as well as the relative alpha amplitude during the peripheral visual test. It was not the case in the non-neurofeedback control group, which performed the tests within the same time frame as the neurofeedback group but without any training sessions. These findings suggest that alpha neurofeedback training was effective in improving peripheral visual performance. To the best of our knowledge, this is the first study to show evidence for performance improvement in peripheral vision via alpha neurofeedback training.     

On an automatic delineator for arterial blood pressure waveforms

Arterial blood pressure waveforms contain rich pathophysiological information; hence receive much attention in cardiovascular health monitoring. To assist computerized analysis, an automatic delineator was proposed for the fiducial points of arterial blood pressure waveforms, namely their onsets, systolic peaks and dicrotic notches. The presented delineator characterizes arterial blood pressure waveforms in a beat-by-beat manner. It firstly seeks the pairs of inflection and zero-crossing points, and then utilizes combinatorial amplitude and interval criteria to select the onset and systolic peak. Once a new beat is settled, the delineator seeks the derivative backward to locate the dicrotic notch in the preceding beat. In a nutshell, the delineator is based on the combinatorial analysis of arterial blood pressure waveforms and their derivatives. Three open databases, with an additional subset database, were utilized for delineator validation and performance evaluation. In terms of beat detection, the delineator achieved an average error rate 1.14%, sensitivity 99.43% and positive predictivity 99.45%. As to dicrotic notch detection, it performed well with an error rate 6.83%, sensitivity 96.53% and positive predictivity 96.64%.     

Identification of a glycoprotein involved in cell cycle progression in yeast

The molecular events of start, the regulatory step that commits yeast cells to DNA replication, have recently begun to be investigated. One of the gene products required for completion of start has been found to have a significant structural homology with oncogenes endowed with protein kinase activity. Our experiments provide data on the biosynthetic pathway of a previously identified labile protein (p100, molecular weight 100,000, isoelectric point of approximately 4.8-5) involved in cell cycle progression at start, which appears to be specifically made during the release from cell cycle arrest of a temperature-sensitive mutant (cdc25) of Saccharomyces cerevisiae. On two-dimensional gel, p100 migrates very close to another 100-kDa labile protein (p100*) which behaves as a cell cycle modulated protein with reduced synthesis in G1. Pulse and chase labeling of protein with [35S]methionine suggests that both p100 and p100* are processed to a protein (p115) of slightly higher molecular weight (Mr = 115,000). Peptide mapping analysis indicates that p100 and p100 yield identical maps and that both p100 and p100* are very much similar to p115. p115 is a glycosylated protein as shown by a labeling experiment with [3H]glucosamine and by the fact that the synthesis of both p100 and p115 is inhibited if cells are cultured in the presence of tunicamycin. A protein having the same heterogeneous aspect of migration on sodium dodecyl sulfate-polyacrylamide gel and the same apparent molecular weight and isoelectric point of p115 is abundantly present in a preparation of membranes from S. cerevisiae and the isolated radioactive p115 comigrates with it. Taken together these results favor the idea that terminal glycosylation of both p100 and p100* gives rise to the fully glycosylated p115 protein which appears to be a membrane-associated protein.     

InSaccharomyces cerevisiae overexpression of hybrid Virus-Like-Particles correlates with altered cell volume distributions

Overexpression of hybrid Virus-Like-Particles (VLP) was found to dramatically affect cell kinetics and morphology with a significant increase in doubling times, induction times and major alterations in cell volume distributions. Optimal expression (ca. 10 mg/l) was obtained with a two-step fermentation strategy (raffinose galactose) coupled to GAL4 overexpression, resulting in partial cell lysis and VLP release.     

Changes in the protein synthesis pattern during a nutritional shift-down transition in Saccharomyces cerevisiae

In Saccharomyces cerevisiae cells (strain A364A) during a shift-down from glucose to raffinose, a rapid reduction in the rate of RNA accumulation was observed whereas the rate of protein accumulation was unaffected for at least 2 h. Following the transition the percentage of unbudded cells slightly increased and the cell volume distribution showed a newly formed subpopulation of smaller cells. To study the effects of the shift-down on the protein synthesis pattern, total [³⁵S]-methionine pulse-labeled extracts were fractionated by high-resolution two-dimensional gel electrophoresis. The synthesis of two classes of proteins (I and II) was modulated during the transitory state of growth: one positively, the other negatively. Two polypeptides of 57 kDa showed the most dramatic increase in synthesis during the shift-down. Also a heat-shock protein (HSP 256) appeared to be positively correlated to the shift-down transition.     

Defects in Assembly of the Extracellular Matrix Are Responsible for Altered Morphogenesis of a Candida albicans phr1 Mutant

Analysis of Candida albicans cells using antibodies directed against Gas1p/Ggp1p, Saccharomyces cerevisiae homolog of Phr1p, revealed that Phr1p is a glycoprotein of about 88 kDa whose accumulation increases with the rise of external pH. This polypeptide is present both in the yeast form and during germ tube induction. In the Phr1⁻ cells at pH 8 the solubility of glucans in alkali is greatly affected. In the parental strain the alkali-soluble/-insoluble glucan ratio shows a 50% decrease at pH 8 with respect to pH 4.5, whereas in the null mutant it is unchanged, indicating the lack of a polymer cross-linker activity induced by the rise of pH. The mutant has a sixfold increase in chitin level and is hypersensitive to calcofluor. Consistently with a role of chitin in strengthening the cell wall, Phr1⁻ cells are more sensitive to nikkomycin Z than the parental strain.     

Three-dimensional structure of the catalytic domain of the yeast β-(1,3)-glucan transferase Gas1: a molecular modeling investigation

The three-dimensional (3D) structure of the catalytic domain of Gas1p, a protein belonging to the only family of β-(1,3)-glucan transferases so far identified in yeasts and some pathogenic fungi (family GH-72), has been predicted by combining results derived from threading methods, multiple sequence alignments and secondary-structure predictions. The 3D model has allowed the identification of several residues that are predicted to play a crucial role in structural integrity, substrate recognition and catalysis. In particular, the model of the catalytic domain can be useful for designing site-directed mutagenesis experiments and for developing inhibitors of Gas1p enzymatic activity. Figure Three-dimensional models of the Gas1p catalytic domain as predicted using as template 7A3H (PDB code) protein Electronic Supplementary Material Supplementary material is available for this article at