Identification of an Xiap-Like Pseudogene on Mouse Chromosome 7

The most thoroughly characterized mammalian IAP is XIAP/BIRC4, which can inhibit caspases 9, 3 and 7, but may also regulate apoptosis through interactions with other proteins such as Smac/DIABLO, HtrA2/Omi, XAF1, TAK1, cIAP1, and cIAP2.High throughput sequencing of the mouse genome revealed the existence of a gene resembling Xiap/Birc4 on mouse chromosome 7. To confirm the existence of this gene, and to determine its functional significance, we performed Southern and Northern blot analysis. This showed the presence of the Xiap-like gene in both wild-type and Xiap gene knock-out mice, but the corresponding mRNA was not detected in any tissues examined by Northern blot. Analysis of the gene sequence in all three possible reading frames predicts that expression of this gene would not give rise to a full-length protein, but only non-functional truncated polypeptides. Because its nucleotide sequence is 92% identical to Xiap, but it has no introns corresponding to those of Xiap, we conclude that Xiap-ps1 is a pseudogene generated by retro-transposition of a spliced Xiap message to chromosome 7.     

The effect of β‐methylation on the conformation of α, β‐dehydrophenylalanine: a DFT study

Dehydroamino acids are non‐coded amino acids that offer unique conformational properties. Dehydrophenylalanine (ΔPhe) is most commonly used to modify bioactive peptides to constrain the topography of the phenyl ring in the side chain, which commonly serves as a pharmacophore. The Ramachandran maps (in the gas phase and in CHCl₃ mimicking environments) of ΔPhe analogues with methyl groups at the β position of the side chain as well as at the C‐terminal amide were calculated using the B3LYP/6‐31 + G** method. Unexpectedly, β‐methylation alone results in an increase of conformational freedom of the affected ΔPhe residue. However, further modification by introducing an additional methyl group at C‐terminal methyl amide results in a steric crowding that fixes the torsion angle ψ of all conformers to the value 123°, regardless of the Z or E position of the phenyl ring. The number of conformers is reduced and the accessible conformational space of the residues is very limited. In particular, (Z)‐Δ(βMe)Phe with the tertiary C‐terminal amide can be classified as the amino acid derivative that has a single conformational state as it seems to adopt only the β conformation. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.     

Inter- and intrachromosomal asynchrony of cell division cycle events in root meristem cells of Allium cepa: possible connection with gradient of cyclin B-like proteins

Alternate treatments of Allium cepa root meristems with hydroxyurea (HU) and caffeine give rise to extremely large and highly elongated cells with atypical images of mitotic divisions, including internuclear asynchrony and an unknown type of interchromosomal asynchrony observed during metaphase-to-anaphase transition. Another type of asynchrony that cannot depend solely on the increased length of cells was observed following long-term incubation of roots with HU. This kind of treatment revealed both cell nuclei entering premature mitosis and, for the first time, an uncommon form of mitotic abnormality manifested in a gradual condensation of chromatin (spanning from interphase to prometaphase). Immunocytochemical study of polykaryotic cells using anti-β tubulin antibodies revealed severe perturbations in the microtubular organization of preprophase bands. Quantitative immunofluorescence measurements of the control cells indicate that the level of cyclin B-like proteins reaches the maximum at the G2 to metaphase transition and then becomes reduced during later stages of mitosis. After long-term incubation with low doses of HU, the amount of cyclin B-like proteins considerably increases, and a significant number of elongated cells show gradients of these proteins spread along successive regions of the perinuclear cytoplasm. It is suggested that there may be a direct link between the effects of HU-mediated deceleration of S- and G2-phases and an enhanced concentration of cyclin B-like proteins. In consequence, the activation of cyclin B-CDK complexes gives rise to an abnormal pattern of premature mitotic chromosome condensation with biphasic nuclear structures having one part of chromatin decondensed, and the other part condensed.     

Individual blastomeres of 16- and 32-cell mouse embryos are able to develop into foetuses and mice

Cell and developmental studies have clarified how, by the time of implantation, the mouse embryo forms three primary cell lineages: epiblast (EPI), primitive endoderm (PE), and trophectoderm (TE). However, it still remains unknown when cells allocated to these three lineages become determined in their developmental fate. To address this question, we studied the developmental potential of single blastomeres derived from 16- and 32-cell stage embryos and supported by carrier, tetraploid blastomeres. We were able to generate singletons, identical twins, triplets, and quadruplets from individual inner and outer cells of 16-cell embryos and, sporadically, foetuses from single cells of 32-cell embryos. The use of embryos constitutively expressing GFP as the donors of single diploid blastomeres enabled us to identify their cell progeny in the constructed 2n↔4n blastocysts. We showed that the descendants of donor blastomeres were able to locate themselves in all three first cell lineages, i.e., epiblast, primitive endoderm, and trophectoderm. In addition, the application of Cdx2 and Gata4 markers for trophectoderm and primitive endoderm, respectively, showed that the expression of these two genes in the descendants of donor blastomeres was either down- or up-regulated, depending on the cell lineage they happened to occupy. Thus, our results demonstrate that up to the early blastocysts stage, the destiny of at least some blastomeres, although they have begun to express markers of different lineage, is still labile.     

QEEG characteristics and spectrum weighted frequency for children diagnosed as autistic spectrum disorder

Background

Autistic spectrum disorders are a group of neurological and developmental disorders associated with social, communication, sensory, behavioral and cognitive impairments, as well as restricted, repetitive patterns of behavior, activities, or interests.The aim of this study was a) to analyze QEEG findings of autistic patients and to compare the results with data base; and b) to introduce the calculation of spectrum weighted frequency (brain rate) as an indicator of general mental arousal in these patients.

Results

Results for Q-EEG shows generally increased delta-theta activity in frontal region of the brain. Changes in QEEG pattern appeared to be in a non-linear correlation with maturational processes.Brain rate measured in CZ shows slow brain activity (5. 86) which is significantly lower than normal and corresponds to low general mental arousal.Recent research has shown that autistic disorders have as their basis disturbances of neural connectivity. Neurofeedback seems capable of remediating such disturbances when these data are considered as part of treatment planning.

Conclusions

Prognosis of this pervasive disorder depends on the intellectual abilities: the better intellectual functioning, the possibilities for life adaptation are higherQEEG shows generally increased delta-theta activity in frontal region of the brain which is related to poor cognitive abilities.Brain rate measured in CZ shows slow brain activity related to under arousal.Pharmacotherapy combined with behavior therapy, social support and especially neurofeedback technique promise slight improvements

     

Proteomic analysis of p38alpha mitogen-activated protein kinase-regulated changes in membrane fractions of RAS-transformed fibroblasts

Oncogenic Ras signaling has been long known to play an important role in tumorigenesis and human cancer. In this report, we have used the sensitive 2-D-DIGE coupled to MS for the identification of proteins differentially expressed at the cell membrane level between oncogenic H-RasV12-transformed wild-type and p38alpha-deficient mouse embryo fibroblasts (MEFs). Following trifluoroethanol solubilization, 76 proteins were found to be differentially regulated. After PMF, 63 spots containing 42 different proteins were unequivocally identified by MALDI-TOF MS coupled with database interrogation. As expected, many of them were membrane proteins. Six proteins were selected for further validation studies based on their potential functional link with malignant transformation and signal transduction. These were prohibitin (PHB), protein disulfide isomerase 3 (PDIA3), focal adhesion kinase 2 (FAK2), c-GMP dependent protein kinase 2 (KGP2), NADH-ubiquinone oxidoreductase 30 kDa subunit (NUGM) and translationally controlled tumor protein (TCTP). All these proteins were up-regulated in the membranes of H-RasV12-transformed p38alpha-/-cells, except for prohibitin, which was down-regulated. An excellent correlation was found between DIGE results and Western blot studies, indicating the reliability of the 2-D-DIGE analysis. The available evidence about the putative function of the identified proteins supports the emerging role of p38alpha as a negative regulator of tumorigenesis. Further studies are in progress to elucidate the implications of these findings in the regulation of H-Ras-induced transformation by p38alpha signaling.     

The relationships between self-efficacy,self-control,chronotype, procrastination and sleep problems in young adults

ABSTRACT

The main aim of our study was to examine whether there was a relationship between psychological characteristics such as self-efficacy, self-control and chronotype as well as procrastination on the one hand and sleep problems on the other. There were 315 young adults aged between 18 and 27 years (M = 20.57). We used the General Procrastination Scale, the General Self-Efficacy Scale (GSES), Brief Self-Control Scale, the Composite Scale of Morningness (CSM) and the Pittsburgh Sleep Quality Index (PSQI). Our results indicated that low self-efficacy, low self-control and eveningness were positive predictors of procrastination. The reciprocal relationship exists between procrastination and sleep problems. Procrastination positively contributed to sleep problems, whereas sleep problems were a negative predictor of procrastination.     

Synthesis and SAR of pyridothiazole substituted pyrimidine derived HCV replication inhibitors

Introduction of a nitrogen atom into the benzene ring of a previously identified HCV replication (replicase) benzothiazole inhibitor 1, resulted in the discovery of the more potent pyridothiazole analogues 3. The potency and PK properties of the compounds were attenuated by the introductions of various functionalities at the R(1), R(2) or R(3) positions of the molecule (compound 3). Inhibitors 38 and 44 displayed excellent potency, selectivity (GAPDH/MTS CC(50)), PK parameters in all species studied, and cross genotype activity.