Structure of the Rtt109-AcCoA/Vps75 complex and implications for chaperone-mediated histone acetylation

Yeast Rtt109 promotes nucleosome assembly and genome stability by acetylating K9, K27, and K56 of histone H3 through interaction with either of two distinct histone chaperones, Vps75 or Asf1. We report the crystal structure of an Rtt109-AcCoA/Vps75 complex revealing an elongated Vps75 homodimer bound to two globular Rtt109 molecules to form a symmetrical holoenzyme with a ～12?? diameter central hole. Vps75 and Rtt109 residues that mediate complex formation in the crystals are also important for Rtt109-Vps75 interaction and H3K9/K27 acetylation both in?vitro and in yeast cells. The same Rtt109 residues do not participate in Asf1-mediated Rtt109 acetylation in?vitro or H3K56 acetylation in yeast cells, demonstrating that Asf1 and Vps75 dictate Rtt109 substrate specificity through distinct mechanisms. These studies also suggest that Vps75 binding stimulates Rtt109 catalytic activity by appropriately presenting the H3-H4 substrate within the central cavity of the holoenzyme to promote H3K9/K27 acetylation of new histones before deposition.     

Evaluation of Physicochemical Activity of Anticancer Fusion Proteins; Enterocin A- R type pyocin-Lactocin-Ligand Against Gastric Cancer Cell Line by Real-Time RT PCR Technique

International Journal of Peptide Research and Therapeutics - Gastric cancer treatment remains a major challenge. There are many reports on the positive efficacy of Bacteriocins associated with...     

TLR Ligands Induce Antiviral Responses in Chicken Macrophages

Chicken macrophages express several receptors for recognition of pathogens, including Toll-like receptors (TLRs). TLRs bind to pathogen-associated molecular patterns (PAMPs) derived from bacterial or viral pathogens leading to the activation of macrophages. Macrophages play a critical role in immunity against viruses, including influenza viruses. The present study was designed to test the hypothesis that treatment of chicken macrophages with TLR ligands reduces avian influenza replication. Furthermore, we sought to study the expression of some of the key mediators involved in the TLR-mediated antiviral responses of macrophages. Chicken macrophages were treated with the TLR2, 3, 4, 7 and 21 ligands, Pam3CSK4, poly(I:C), LPS, R848 and CpG ODN, respectively, at different doses and time points pre- and post-H4N6 avian influenza virus (AIV) infection. The results revealed that pre-treatment of macrophages with Pam3CSK4, LPS and CpG ODN reduced the replication of AIV in chicken macrophages. In addition, the relative expression of genes involved in inflammatory and antiviral responses were quantified at 3, 8 and 18 hours post-treatment with the TLR2, 4 and 21 ligands. Pam3CSK4, LPS and CpG ODN increased the expression of interleukin (IL)-1β, interferon (IFN)-γ, IFN-β and interferon regulatory factor (IFR) 7. The expression of these genes correlated with the reduction of viral replication in macrophages. These results shed light on the process of immunity to AIV in chickens.     

The phylogenetic position of an <Emphasis Type="Italic">Armillaria</Emphasis> species from Amami-Oshima,a subtropical island of Japan,based on elongation factor and ITS sequences

An undetermined Armillaria species was collected on Amami-Oshima, a subtropical island of Japan. The phylogenetic position of the Armillaria sp. was determined using sequences of the elongation factor-1α (EF-1α) gene and the internal transcribed spacer (ITS) region (ITS1-5.8S-ITS2) of ribosomal DNA (rDNA). The phylogenetic analyses based on EF-1α and ITS sequences showed that this species differs from known Japanese taxa of Armillaria. The sequences of this species and A. novae-zelandiae from Southeast Asia were contained in a strongly supported clade, which was adjacent to a well-supported sister clade containing A. novae-zelandiae from Australia and New Zealand.     

Sleep habits of Iranian pre-school children in an urban area: Late sleeping and sleep debt in children

Using BEARS (Bedtime problems, Excessive sleepiness, Awakenings during the night, Regularity of sleep, Snoring), and CSHQ (Children’s Sleep Habits Questionnaires) screening tools with 224 participants revealed that Iranian children have shorter night sleep duration than expected (9.54 vs 12 h) for their age group. Earlier sleepers had longer night sleep duration (10:36 ± 1:12; 9:12 ± 1:06 h, P > 0.001), and total daily sleep time (11:36 ± 1:42; 10:36 ± 1:30 h, P = 0.005) than late sleepers. A majority (85%) of naptakers had sleep bedtime of 22:00 or later. The poor sleep quality of Iranian preschool children is probably due to cultural characteristics, climate differences, or harmful sleep habits.

     

A cross-sectional study of barriers to personal health record use among patients attending a safety-net clinic

Background

Personal health records (PHR) may improve patients'' health by providing access to and context for health information. Among patients receiving care at a safety-net HIV/AIDS clinic, we examined the hypothesis that a mental health (MH) or substance use (SU) condition represents a barrier to engagement with web-based health information, as measured by consent to participate in a trial that provided access to personal (PHR) or general (non-PHR) health information portals and by completion of baseline study surveys posted there.

Methods

Participants were individually trained to access and navigate individualized online accounts and to complete study surveys. In response to need, during accrual months 4 to 12 we enhanced participant training to encourage survey completion with the help of staff. Using logistic regression models, we estimated odds ratios for study participation and for survey completion by combined MH/SU status, adjusted for levels of computer competency, on-study training, and demographics.

Results

Among 2,871 clinic patients, 70% had MH/SU conditions, with depression (38%) and methamphetamine use (17%) most commonly documented. Middle-aged patients and those with a MH/SU condition were over-represented among study participants (N = 338). Survey completion was statistically independent of MH/SU status (OR, 1.85 [95% CI, 0.93–3.66]) but tended to be higher among those with MH/SU conditions. Completion rates were low among beginner computer users, regardless of training level (<50%), but adequate among advanced users (>70%).

Conclusions

Among patients attending a safety-net clinic, MH/SU conditions were not barriers to engagement with web-based health information. Instead, level of computer competency was useful for identifying individuals requiring substantial computer training in order to fully participate in the study. Intensive on-study training was insufficient to enable beginner computer users to complete study surveys.     

Nitrite as a candidate substrate in microbial fuel cells

Current generation using nitrite as substrate (pH 6.9, 40 mgN l(-1)) in a nitrite-fed microbial fuel cell was investigated under anaerobic and aerobic anodic conditions as an alternative to the biological nitrite oxidation process. Cell current, coulombic efficiency (CE) and power generation of 0.04 mA, 30 ± 2 % and 19.3 ± 3.3 μW m(-2), respectively, were observed under anaerobic conditions while complete nitrite degradation (no current) was obtained under aerobic conditions. Switching from aerobic to anaerobic anode enhanced the CE and power generation (39 ± 1 % and 29 ± 4.3 μW m(-2)).     

Quantitative genetics of temperature performance curves of Neurospora crassa

Earth's temperature is increasing due to anthropogenic CO emissions; and organisms need either to adapt to higher temperatures, migrate into colder areas, or face extinction. Temperature affects nearly all aspects of an organism's physiology via its influence on metabolic rate and protein structure, therefore genetic adaptation to increased temperature may be much harder to achieve compared to other abiotic stresses. There is still much to be learned about the evolutionary potential for adaptation to higher temperatures, therefore we studied the quantitative genetics of growth rates in different temperatures that make up the thermal performance curve of the fungal model system Neurospora crassa. We studied the amount of genetic variation for thermal performance curves and examined possible genetic constraints by estimating the G -matrix. We observed a substantial amount of genetic variation for growth in different temperatures, and most genetic variation was for performance curve elevation. Contrary to common theoretical assumptions, we did not find strong evidence for genetic trade-offs for growth between hotter and colder temperatures. We also simulated short-term evolution of thermal performance curves of N. crassa, and suggest that they can have versatile responses to selection.