Idas, a novel phylogenetically conserved geminin-related protein, binds to geminin and is required for cell cycle progression.

Development and homeostasis of multicellular organisms relies on an intricate balance between cell proliferation and differentiation. Geminin regulates the cell cycle by directly binding and inhibiting the DNA replication licensing factor Cdt1. Geminin also interacts with transcriptional regulators of differentiation and chromatin remodelling factors, and its balanced interactions are implicated in proliferation-differentiation decisions during development. Here, we describe Idas (Idas being a cousin of the Gemini in Ancient Greek Mythology), a previously uncharacterised coiled-coil protein related to Geminin. We show that human Idas localizes to the nucleus, forms a complex with Geminin both in cells and in vitro through coiled-coil mediated interactions, and can change Geminin subcellular localization. Idas does not associate with Cdt1 and prevents Geminin from binding to Cdt1 in vitro. Idas depletion from cells affects cell cycle progression; cells accumulate in S phase and are unable to efficiently progress to mitosis. Idas protein levels decrease in anaphase, whereas its overexpression causes mitotic defects. During development, we show that Idas exhibits high level expression in the choroid plexus and the cortical hem of the mouse telencephalon. Our data highlight Idas as a novel Geminin binding partner, implicated in cell cycle progression, and a putative regulator of proliferation-differentiation decisions during development.

ProteinCCD: enabling the design of protein truncation constructs for expression and crystallization experiments.

ProteinCCD (CCD for Crystallographic Construct Design) aims to facilitate a common practice in structural biology, namely the design of several truncation constructs of the protein under investigation, based on experimental data or on sequence analysis tools. ProteinCCD functions as a meta-server, available online at http://xtal.nki.nl/ccd, that collects information from prediction servers concerning secondary structure, disorder, coiled coils, transmembrane segments, domains and domain linkers. It then displays a condensed view of all results against the protein sequence. The user can study the output and choose interactively possible starts and ends for suitable protein constructs. Since the required input to ProteinCCD is the DNA and not the protein sequence, once the starts and ends of constructs are chosen, the software can automatically design the oligonucleotides needed for PCR amplification of all constructs. ProteinCCD outputs a comprehensive view of all constructs and all oligos needed for bookkeeping or for direct copy-paste ordering of the designed oligonucleotides.

Structures of native human thymidine phosphorylase and in complex with 5-iodouracil.

Thymidine phosphorylase (TP) first identified as platelet derived endothelial cell growth factor (PD-ECGF) plays a key role in nucleoside metabolism. Human TP (hTP) is implicated in angiogenesis and is overexpressed in several solid tumors. Here, we report the crystal structures of recombinant hTP and its complex with a substrate 5-iodouracil (5IUR) at 3.0 and 2.5A, respectively. In addition, we provide information on the role of specific residues in the enzymatic activity of hTP through mutagenesis and kinetic studies.

COPD characteristics and socioeconomic burden in Hellenic correctional institutions.

BACKGROUND: The high prevalence of smoking (80%) in Greek correctional institutions is anticipated to result in high prevalence of COPD in such settings. AIM: The aim of the Greek obstructive luNg disease epidemiOlogy and health economics Study In corrective institutionS (GNOSIS) is to determine the prevalence of smoking and COPD among inmates and to assess the health-related quality of life. METHODS: GNOSIS, a cross-sectional epidemiological study, was conducted between March 2011 and December 2011 in seven correctional institutions in Greece. RESULTS: A total of 552 participants, 91.3% male, median age of 43.0 years (interquartile range: 35-53), were enrolled. COPD prevalence was 6.0% and was found to increase with age (18.6% among those ≥60 years), length of prison stay, and length of sentence. Of the participants diagnosed with COPD, 36.4% were diagnosed with Global initiative for chronic Obstructive Lung Disease (GOLD) stage I and 51.5% were diagnosed with stage II. Dyspnea severity was assessed as grades 0-1 on the medical research council dyspnea scale for 88.3%, while 31% reported ≥2 COPD exacerbations in the past year. Seventy-nine percent of the total number of the participants were smokers, with a median smoking of 20.0 cigarettes per day, while 42.9% were assessed as having a strong addiction to nicotine. The median EuroQol visual analog scale score was 70.0 (interquartile range: 60.0-90.0). Problems in the dimension of anxiety/depression were reported by 82.8%. CONCLUSION: The results of the study support the notion that the prevalence of COPD among inmates of Greek correctional institutions may increase in the following years. The findings underscore the importance of taking actions to limit COPD prevalence and its risk factors in the Greek correctional system.

Frequency and risk factors of COPD exacerbations and hospitalizations: a nationwide study in Greece (Greek Obstructive Lung Disease Epidemiology and health ecoNomics: GOLDEN study).

BACKGROUND: COPD exacerbations and hospitalizations have been associated with poor prognosis for the COPD patient. OBJECTIVE: To evaluate the frequency and risk factors of COPD exacerbations, hospitalizations, and admissions to intensive care units (ICUs) in Greece by a nationwide cross-sectional study. MATERIALS AND METHODS: A nationwide observational, multicenter, cross-sectional study was conducted in the clinical practice setting of respiratory medicine physicians over a 6 month-period (October 2010 to March 2011). A total of 6,125 COPD patients were recruited by 199 respiratory physicians. RESULTS: Participants had a median age of 68.0 years, 71.3% were males, and 71.8% suffered from comorbidities. The median disease duration was 10.0 years. Of the patients, 45.3% were classified as having GOLD (Global initiative for chronic Obstructive Lung Disease) stage III or IV COPD. Patients with four or more comorbidities had 78.5% and threefold-higher than expected number of exacerbations and hospitalizations, respectively, as well as fivefold-higher risk of admission to the ICU compared to those with no comorbidities. Obese patients had 6.2% fewer expected exacerbations compared to those with a normal body mass index. Patients with GOLD stage IV had 74.5% and fivefold-higher expected number of exacerbations and hospitalizations, respectively, and nearly threefold-higher risk of admission to the ICU compared to stage I patients. An additional risk factor for exacerbations and hospitalizations was low compliance with treatment: 45% of patients reported forgetting to take their medication, and 81% reported a preference for a treatment with a lower dosing frequency. CONCLUSION: Comorbidities, disease severity, and compliance with treatment were identified as the most notable risk factors for exacerbations, hospitalizations, and ICU admissions. The results point to the need for a multifactorial approach for the COPD patient and for the development of strategies that can increase patient compliance with treatment.

Characteristics of prevalent and new COPD cases in Greece: the GOLDEN study.

BACKGROUND: Greece has one of the highest rates of smoking and chronic obstructive pulmonary disease (COPD) in Europe. AIM: The study aimed to record both the disease characteristics among a sample of Greek COPD patients and the nationwide rates of newly diagnosed COPD cases. METHODS: In this noninterventional, epidemiological cross-sectional study, a representative nationwide sample of 45 respiratory centers provided data on the following: 1) the demographic and clinical characteristics of COPD patients and 2) newly diagnosed COPD cases monitored over a period of 6 months by each physician. RESULTS: Data from 6,125 COPD patients were collected. Advanced age (median age: 68 years), male predominance (71.3%), largely overweight status with median body mass index (BMI) =27.5 kg/m(2), high percentage of current and ex-smokers (89.8%), and presence of comorbidities (81.9%) were evident in the sample. According to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2011 criteria, majority of the COPD patients had moderate or severe airflow limitation (61%). Severity of airflow limitation was significantly associated with older age, male sex, obesity, ex-smoking status, and presence of comorbidity (all P-values <0.001). A total of 61.3% of the patients received medication, mostly bronchodilators (64.4%) and fixed-dose combinations of long-acting ß2-agonists and inhaled corticosteroids (39.9%), while 35.9% reported taking medication on demand. The majority (81.1%) of patients reported a preference for fewer inhalations of their bronchodilator therapy. Based on the mixed-effect Poisson model, the rate of newly diagnosed COPD cases was estimated to be 18.2% (95% confidence interval: 14.9-22.3) per pulmonologist/3 months. Of those newly diagnosed, the majority of patients had mild or moderate airflow limitation (78.2%). CONCLUSION: The Greek Obstructive Lung Disease Epidemiology and health ecoNomics study reflected the real-life profile of COPD patients and provided evidence on the profile of new COPD cases in Greece. Various demographic factors were delineated, which can assist in designing more effective diagnostic and management strategies for COPD in Greece.

Sex discrepancies in COPD patients and burden of the disease in females: a nationwide study in Greece (Greek Obstructive Lung Disease Epidemiology and health ecoNomics: GOLDEN study).

BACKGROUND: The prevalence of chronic obstructive pulmonary disease (COPD) in females appears to be increasing. Recent studies have revealed that the percentage of women with COPD in Greece is approximately 12.5%. AIMS: To evaluate the burden of COPD among males and females in Greece through a nationwide cross-sectional survey and to explore sex differences regarding functional characteristics and exacerbation frequency. METHODS: Data collection was completed in a 6-month period. The present study followed a nationwide sampling approach of respiratory medicine physicians. The sampling approach included three steps: 1) estimation of expected incidence and prevalence of COPD cases in each prefecture of Greece and in total; 2) estimation of expected incidence of COPD cases per physician in each prefecture; and 3) creation of a frame of three different sampling zones. Following this sampling, data were provided by 199 respiratory physicians. RESULTS: The participating physicians provided data from 6,125 COPD patients. Female patients represented 28.7% of the study participants. Female COPD patients were, on average, 5 years younger than male COPD patients. Never smokers accounted for 9.4% within female patients, compared to 2.7% of males (P<0.001). Female patients were characterized by milder forms of the disease. Comorbidities were more prevalent in men, with the exception of gastroesophageal reflux (14.6% versus 17.1% for men and women, respectively, P=0.013). Female COPD patients had a higher expected number of outpatient visits per year (by 8.9%) than males (P<0.001), although hospital admissions did not differ significantly between sexes (P=0.116). Females had fewer absences from work due to COPD per year, by 19.0% (P<0.001), compared to males. CONCLUSION: The differences observed between male and female COPD patients provide valuable information which could aid the prevention and management of COPD in Greece.

Systematic bioinformatics and experimental validation of yeast complexes reduces the rate of attrition during structural investigations.

For high-throughput structural studies of protein complexes of composition inferred from proteomics data, it is crucial that candidate complexes are selected accurately. Herein, we exemplify a procedure that combines a bioinformatics tool for complex selection with in vivo validation, to deliver structural results in a medium-throughout manner. We have selected a set of 20 yeast complexes, which were predicted to be feasible by either an automated bioinformatics algorithm, by manual inspection of primary data, or by literature searches. These complexes were validated with two straightforward and efficient biochemical assays, and heterologous expression technologies of complex components were then used to produce the complexes to assess their feasibility experimentally. Approximately one-half of the selected complexes were useful for structural studies, and we detail one particular success story. Our results underscore the importance of accurate target selection and validation in avoiding transient, unstable, or simply nonexistent complexes from the outset.