ABSTRACT
PURPOSE: The first aim was to evaluate feasibility and reproducibility of 2-dimensional ultrasound (2D) shear wave elastography (SWE) of human fetal lungs and liver between 24 and 34weeks of gestation. The second aim was to model fetal lung-to-liver elastography ratio (LLE ratio) and to assess its variations according to gestational age and maternal administration of corticosteroids. MATERIAL AND METHODS: 2D-SWE examinations were prospectively performed in fetuses of women with an uncomplicated pregnancy (group 1) and fetuses of women with a threatened preterm labor requiring administration of corticosteroids (group 2). Two 2D-SWE examinations were performed at "day 0" and "day 2" in group 1; before and 24hours after a course of corticosteroid in group 2. Three operators performed 2 cycles of 3 measurements on the lung (regions A1, A2, A3) and the liver (regions IV, V, VI). Repeatability and reproducibility of measurements were calculated. The fetal LLE ratio was modeled from the most reproducible regions. RESULTS: Fifty-five women were enrolled in group 1 and 48 in group 2. For the lung, 8.6% of measurements were considered invalid and 6.9% for the liver. The most reproducible region for the lung was A3 [ICC between 0.70 (95% CI: 0.42-0.85) and 0.78 (95% CI: 0.48-0.90)] and region VI for the liver [ICC between 0.70 (95% CI: 0.40-0.85) and 0.84 (95% CI: 0.60-0.94)]. According to gestational age, a moderate positive linear correlation was found for stiffness values of A3 (R=0.56), V (R=0.46) and VI (R=0.44). LLE ratio values at "day 0" were not different between the two groups but decreased at "day 2" in group 2 (0.2; 95% CI: 0.07-0.34; P<0.001). CONCLUSION: Quantitative fetal lung and liver stiffness measurements are possible with 2D-SWE with acceptable reproducibility.
Subject(s)
Elasticity Imaging Techniques , Liver/diagnostic imaging , Liver/embryology , Lung/diagnostic imaging , Lung/embryology , Adult , Case-Control Studies , Elasticity Imaging Techniques/methods , Feasibility Studies , Female , Gestational Age , Humans , Pilot Projects , Pregnancy , Prospective Studies , Reproducibility of Results , Ultrasonography, Prenatal , Young AdultABSTRACT
Self-administration of antibiotics using elastomeric pumps has become the most frequently used treatment modality at the outpatient parenteral antimicrobial therapy (OPAT) unit of the University Hospital of Lausanne. However, it remains unknown how comfortable patients feel using this mode of treatment. A questionnaire was offered to all patients treated at the OPAT unit between June 2014 and December 2015. The questionnaire was distributed to 188 patients and 112 questionnaires were returned. Seventy-one patients were treated by self-administration, 21 attended the OPAT unit on a daily basis, and 20 received their antibiotics from home-care nurses. Overall, 83-97% of the patients gave the highest possible scores to the four items evaluating their global satisfaction. Subjects treated by self-administration gave a significantly better rating to 6 of the 17 semi-quantitative questions than the patients treated at the OPAT unit or by home-care nurses. There was no item which was more poorly rated by patients treated by self-administered OPAT than by the other treatment groups. In conclusion satisfaction was high in all patients treated by OPAT. The particularly high satisfaction of patients treated by self-administration of antibiotics with elastomeric pumps suggests that a significant number of patients are happy to take over some responsibility for their treatment. Patients' capacity to appropriate their care themselves should not be underestimated by health care professionals.
Subject(s)
Ambulatory Care/methods , Anti-Bacterial Agents/administration & dosage , Bacterial Infections/drug therapy , Outpatients , Patient Satisfaction , Administration, Intravenous , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Self Administration , Surveys and Questionnaires , Switzerland , Young AdultABSTRACT
Outpatient parenteral antimicrobial therapy (OPAT) has been recognised as a useful, cost-effective and safe alternative to inpatient treatment, but no formal OPAT unit existed in Switzerland until recently. In December 2013 an OPAT unit was established at Lausanne University Hospital. We review here the experience of this new OPAT unit after 18 months of activity. Patient characteristics, clinical activities and outcomes were recorded prospectively. Need and acceptance was evaluated as number of OPAT courses administered and number of patients refusing OPAT. Safety and efficacy were evaluated as: (1) adverse events linked to antimicrobials and catheters, (2) re-admission to hospital, (3) rate of treatment failures and (4) mortality. Over 18 months, 179 courses of OPAT were administered. Acceptance was high with only four patients refusing OPAT. Urinary tract infections with resistant bacteria and musculoskeletal infections were the most common diagnoses. Self-administration of antibiotics using elastomeric pumps became rapidly the most frequently used approach. Sixteen patients presented with adverse events linked to antimicrobials and catheters. OPAT-related readmissions occurred in nine patients. The overall cure rate was 94 %. This study shows that OPAT is very well accepted by patients and medical staff, even in a setting which has not used this type of treatment approach until now. Self-administration using elastomeric pumps proved to be particularly useful, safe and efficient. OPAT offers a good alternative to hospitalisation for patients presenting with infections due to resistant bacteria that cannot be treated orally anymore and for difficult to treat infections.
Subject(s)
Ambulatory Care , Anti-Infective Agents/administration & dosage , Bacterial Infections/drug therapy , Adolescent , Adult , Aged , Aged, 80 and over , Anti-Infective Agents/adverse effects , Bacterial Infections/diagnosis , Bacterial Infections/microbiology , Female , Humans , Infusions, Parenteral , Male , Middle Aged , Recurrence , Switzerland/epidemiology , Treatment Outcome , Young AdultABSTRACT
The black-chinned tilapia Sarotherodon melanotheron heudelotii is an ecologically appealing model as it shows exceptional adaptive capacities, especially with regard to salinity. In spite of this, this species is devoid of genomic resources, which impedes the understanding of such remarkable features. De novo assembly of transcript sequences produced by next-generation sequencing technologies offers a rapid approach to obtain expressed gene sequences for non-model organisms. It also facilitates the development of quantitative real-time PCR (qPCR) assays for analysing gene expression under different environmental conditions. Nevertheless, obtaining accurate and reliable qPCR results from such data requires a number of validations prior to interpretation. The transcriptome of S. melanotheron was sequenced to discover transcripts potentially involved in the plasticity of male reproduction in response to salinity variations. A set of 54 candidate and reference genes was selected through a digital gene expression (DGE) approach, and a de novo qPCR assay using these genes was validated for further detailed expression analyses. A user-friendly web interface was created for easy handling of the sequence data. This sequence collection represents a major transcriptomic resource for S. melanotheron and will provide a useful tool for functional genomics and genetics studies.
Subject(s)
Cichlids/genetics , Cichlids/physiology , Osmotic Pressure , Salinity , Transcriptome , Animals , Computational Biology , High-Throughput Nucleotide Sequencing , Molecular Sequence Data , Sequence AnalysisABSTRACT
OBJECTIVE: The study objective was to assess the awareness of standard precautions (SP) among healthcare professionals, 1 year after the latest national guidelines were issued. METHODS: A multicenter cross-sectional survey was conducted in 34 volunteer institutions in 2010. Data was collected using an anonymous and self-administered questionnaire. The data was analyzed with a program developed from Epi-Info software. RESULTS: Four thousand four hundred and thirty-nine questionnaires were analyzed. Most respondents were nurses (44.1%) or nurses' aides (26.7%) followed by physicians (3.5%). 25% of respondents had participated in specific PS training in the previous 5 years. The percentage of correct answers for each question ranged from 37.1 to 91%. There was 72.6% of correct answers on hand hygiene but only 7.3% of correct answers on use of appropriate barriers and disposal of needles. 39.3% of respondents gave correct answers to eight or more of the 10 SP questions. The level of knowledge of nurses was higher compared to other professionals. The lowest level of knowledge was observed in long-term care and psychiatric institutions. CONCLUSIONS: The knowledge of healthcare professionals on use of appropriate protective barriers and disposal of needles is still too limited. The survey results should be used to develop adequate and targeted educational interventions.
Subject(s)
Health Facilities/statistics & numerical data , Health Personnel/psychology , Knowledge , Universal Precautions , Adult , Cross-Sectional Studies , Female , France , Guideline Adherence/statistics & numerical data , Hand Disinfection/standards , Health Care Surveys , Humans , Male , Medical Waste Disposal/standards , Middle Aged , Nurses/psychology , Nursing Assistants/psychology , Physicians/psychology , Surveys and Questionnaires , Universal Precautions/methodsABSTRACT
Epithelial-to-mesenchymal transition (EMT) is closely linked to conversion of early-stage tumours into invasive malignancies. Many signalling pathways are involved in EMT, but the key regulatory kinases in this important process have not been clearly identified. Protein kinase CK2 is a multi-subunit protein kinase, which, when overexpressed, has been linked to disease progression and poor prognosis in various cancers. Specifically, overexpression of CK2α in human breast cancers is correlated with metastatic risk. In this article, we show that an imbalance of CK2 subunits reflected by a decrease in the CK2ß regulatory subunit in a subset of breast tumour samples is correlated with induction of EMT-related markers. CK2ß-depleted epithelial cells displayed EMT-like morphological changes, enhanced migration, and anchorage-independent growth, all of which require Snail1 induction. In epithelial cells, Snail1 stability is negatively regulated by CK2 and GSK3ß through synergistic hierarchal phosphorylation. This process depends strongly on CK2ß, thus confirming that CK2 functions upstream of Snail1. In primary breast tumours, CK2ß underexpression also correlates strongly with expression of EMT markers, emphasizing the link between asymmetric expression of CK2 subunits and EMT in vivo. Our results therefore highlight the importance of CK2ß in controlling epithelial cell plasticity. They show that CK2 holoenzyme activity is essential to suppress EMT, and that it contributes to maintaining a normal epithelial morphology. This study also suggests that unbalanced expression of CK2 subunits may drive EMT, thereby contributing to tumour progression.
Subject(s)
Casein Kinase II/genetics , Epithelial-Mesenchymal Transition/genetics , Gene Expression Regulation, Enzymologic/physiology , Transcription Factors/genetics , Breast Neoplasms/genetics , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Carcinoma/genetics , Carcinoma/metabolism , Carcinoma/pathology , Casein Kinase II/metabolism , Casein Kinase II/physiology , Cells, Cultured , Female , Gene Expression Profiling , Gene Expression Regulation, Neoplastic , Humans , Isoenzymes/genetics , Isoenzymes/metabolism , Microarray Analysis , Models, Biological , Protein Subunits/genetics , Protein Subunits/metabolism , Snail Family Transcription Factors , Tissue Array Analysis , Transcription Factors/metabolism , Transcription Factors/physiology , Up-Regulation/geneticsABSTRACT
Protein kinase CK2 targets a vast array of substrates located in a number of cellular compartments, making the challenge of discriminating among these substrates a daunting task. However, as a signaling protein, CK2 could be targeted to different cellular compartments in response to various stress stimuli such as heat shock, UV irradiation, hypoxia, DNA damage and viral infections. This review will be focused on the evidence that the dynamic association of CK2 subunits and the substrate-dependent subcellular targeting of the enzyme are a likely point of regulation in response to a variety of signaling events. We propose that in addition to enzymatic substrate recognition, regulated CK2 localization to specific compartments should help to provide the exquisite specificity required for robust signal transduction.
Subject(s)
Casein Kinase II/physiology , Signal Transduction/physiology , Animals , Cell Membrane/metabolism , Cell Nucleus/metabolism , Humans , Isoenzymes/physiology , Phosphorylation , Protein Binding , Protein Conformation , Protein Transport/physiology , Substrate SpecificityABSTRACT
The August 2003 heat wave in France resulted in many thousands of excess deaths particularly of elderly people. Individual and environmental risk factors for death among the community-dwelling elderly were identified. We conducted a case-control survey and defined cases as people aged 65 years and older who lived at home and died from August 8 through August 13 from causes other than accident, suicide, or surgical complications. Controls were matched with cases for age, sex, and residential area. Interviewers used questionnaires to collect data. Satellite pictures provided profiles of the heat island characteristics around the homes. Lack of mobility was a major risk factor along with some pre-existing medical conditions. Housing characteristics associated with death were lack of thermal insulation and sleeping on the top floor, right under the roof. The temperature around the building was a major risk factor. Behaviour such as dressing lightly and use of cooling techniques and devices were protective factors. These findings suggest people with pre-existing medical conditions were likely to be vulnerable during heat waves and need information on how to adjust daily routines to heat waves. In the long term, building insulation and urban planning must be adapted to provide protection from possible heat waves.
Subject(s)
Aged, 80 and over/statistics & numerical data , Heat Stroke/etiology , Heat Stroke/mortality , Housing/statistics & numerical data , Temperature , Air Conditioning , Case-Control Studies , City Planning , Comorbidity , Female , France , Geriatric Assessment , Health Education , Health Services Needs and Demand , Heat Stroke/prevention & control , Humans , Male , Meteorological Concepts , Mobility Limitation , Multivariate Analysis , Public Health Practice , Residence Characteristics/statistics & numerical data , Risk Assessment , Risk Factors , Socioeconomic Factors , Surveys and Questionnaires , Urban Health/statistics & numerical dataABSTRACT
Based on the perturbation of its expression in human cancers and on its involvement in transformation and tumorigenesis, protein kinase CK2 has recently attracted attention as a potential therapeutic target. To assess the value of CK2 as a target for antiproliferative strategies, we have initiated a program aiming to develop inhibitors targeting specifically the regulatory CK2beta subunit. Here, we use a two-hybrid approach to isolate from combinatorial libraries, peptide aptamers that specifically interact with CK2beta. One of these (P1), which has significant sequence homology to the cytomegalovirus IE2 protein, binds with high affinity to the N-terminal domain of CK2beta without disrupting the formation of the CK2 holoenzyme. Expression of green fluorescent protein (GFP)-P1 in different mammalian cell lines activates p53 phosphorylation on serine 15, induces an upregulation of p21 and the release of the Cyt-C and apoptosis-inducing factor proapoptotic proteins triggering caspase-dependent and caspase-independent apoptosis. GFP-P1-induced apoptosis is associated with a p53-dependent pathway as cell death was abrogated in p53 knocked out cells. In summary, our data show that genetically selected peptide aptamers that specifically target CK2beta can induce apoptosis in mammalian cells through the recruitment of a p53-dependent apoptosis pathway. They also emphasize the critical role of CK2beta for cell survival and might allow the design of novel proapoptotic agents targeting this protein.
Subject(s)
Aptamers, Peptide/pharmacology , Casein Kinase II/physiology , Cell Survival/physiology , Tumor Suppressor Protein p53/physiology , 3T3 Cells , Amino Acid Sequence , Animals , Apoptosis/drug effects , Apoptosis/physiology , Aptamers, Peptide/chemistry , Base Sequence , DNA Primers , HeLa Cells , Humans , Immunoprecipitation , Mice , Molecular Sequence Data , Surface Plasmon ResonanceABSTRACT
Epstein-Barr virus (EBV) is associated with lymphoma in immunocompromised patients. This study provides evidence that the expression of EBV nuclear antigen-3 genes can be directed from the F promoter in different type I Burkitt's lymphoma cell lines and in some lymphomas from human immunodeficiency virus-infected patients. This expression occurs predominantly after induction of the EBV lytic cycle.
Subject(s)
Burkitt Lymphoma/virology , Epstein-Barr Virus Nuclear Antigens/metabolism , Gene Expression , Herpesvirus 4, Human/physiology , Lymphoma, AIDS-Related/virology , Virus Latency , Base Sequence , Cell Line , DNA, Viral/genetics , Epstein-Barr Virus Nuclear Antigens/analysis , Epstein-Barr Virus Nuclear Antigens/genetics , Herpesvirus 4, Human/genetics , Humans , Immunohistochemistry , Molecular Sequence Data , Promoter Regions, Genetic , RNA, Messenger/genetics , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
Surface plasmon resonance has been used to study the interaction between the subunits composing protein kinase CK2 (two catalytic, alpha-subunits, and two regulatory, beta-subunits), as well as the interaction of each subunit with two types of protein substrates, casein, the phosphorylation of which is activated by the regulatory subunit, and calmodulin, which belongs to the kind of substrates on which the catalytic subunit is downregulated by the regulatory subunit. The interaction of casein with the catalytic subunit differs from the interaction with the holoenzyme. Similarly to the interaction with the regulatory subunit, the catalytic subunit interacts with the protein substrate forming a very stable, irreversible complex. The reconstituted holoenzyme, however, binds casein reversibly, displaying a binding mode similar to that displayed by the regulatory subunit. The interaction of calmodulin with the catalytic subunit gives place, like in the case of casein, to an irreversible complex. The interactions with the regulatory subunit and with the holoenzyme were practically negligible, and the interaction with the regulatory subunit disappeared upon increasing the temperature value to close to 30 degrees C. The presence of polylysine induced a high increase in the extent of calmodulin binding to the holoenzyme. The results obtained suggest that CK2beta subunit and protein substrates share a common, or at least an overlapping, site of interaction on the catalytic subunit. The interaction between both subunits would prevent substrates from binding irreversibly to alpha subunit, and, at the same time, it would generate a new and milder site of interaction between the whole holoenzyme and the protein substrate. The main difference between casein and calmodulin would consist in the lower affinity display by the last for the new site generated upon the binding of the regulatory subunit, in the absence of polycations like polylysine.
Subject(s)
Calmodulin/chemistry , Caseins/chemistry , Protein Serine-Threonine Kinases/chemistry , Binding Sites , Casein Kinase II , Cell Division , Crystallography, X-Ray , Dimerization , Escherichia coli/metabolism , Hydrogen-Ion Concentration , Polylysine/chemistry , Protein Binding , Protein Structure, Tertiary , Recombinant Proteins/metabolism , Surface Plasmon Resonance , Temperature , Time FactorsABSTRACT
We have generated fusion proteins between the subunits of CK2 and GFP and characterized their behaviour in living cells. The expressed fusion proteins were functional and interacted with endogenous CK2. Imaging of NIH3T3 cells expressing low level of GFP-CK2alpha or GFP-CK2beta showed that both proteins were mostly nuclear in interphase. Both CK2 subunits contain nuclear localization domains that target them independently to the nucleus. Once in the nucleus, both subunits diffused rapidly in the nucleoplasm. In mitotic cells, CK2 subunits were dispersed throughout the cytoplasm and were not associated to chromatin. Our data are compatible with the idea that each subunit can translocate individually to the nucleus to interact with each other or with important cellular partners. Understanding the molecular mechanisms which regulate the dynamic localization of CK2 subunits will be of central importance.
Subject(s)
Cell Nucleus/enzymology , Protein Serine-Threonine Kinases/biosynthesis , Protein Serine-Threonine Kinases/genetics , 3T3 Cells , Active Transport, Cell Nucleus , Animals , Casein Kinase II , Cell Line , Cell Nucleus/metabolism , Chromatin/metabolism , Cytoplasm/metabolism , Green Fluorescent Proteins , HeLa Cells , Humans , K562 Cells , Luminescent Proteins/metabolism , Mice , Microscopy, Fluorescence , Mitosis , Plasmids , Protein Binding , Protein Structure, Tertiary , Recombinant Fusion Proteins/metabolism , TransfectionABSTRACT
DNA topoisomerase II alpha is required for chromatin condensation during prophase. This process is temporally linked with the appearance of mitosis-specific phosphorylation sites on topoisomerase IIalpha including one recognized by the MPM-2 monoclonal antibody. We now report that the ability of mitotic extracts to create the MPM-2 epitope on human topoisomerase II alpha is abolished by immunodepletion of protein kinase CK2. Furthermore, the MPM-2 phosphoepitope on topoisomerase II alpha can be generated by purified CK2. Phosphorylation of C-truncated topoisomerase II alpha mutant proteins conclusively shows, that the MPM-2 epitope is present in the last 163 amino acids. Use of peptides containing all conserved CK2 consensus sites in this region indicates that only the peptide containing Arg-1466 to Ala-1485 is able to compete with topoisomerase II alpha for binding of the MPM-2 antibody. Replacement of Ser-1469 with Ala abolishes the ability of the phosphorylated peptide to bind to the MPM-2 antibody while a peptide containing phosphorylated Ser-1469 binds tightly. Surprisingly, the MPM-2 phosphoepitope influences neither the catalytic activity of topoisomerase II alpha nor its ability to form molecular complexes with CK2 in vitro. In conclusion, we have identified protein kinase CK2 as a new MPM-2 kinase able to phosphorylate an important mitotic protein, topoisomerase II alpha, on Ser-1469.
Subject(s)
Cell Cycle Proteins , DNA Topoisomerases, Type II , DNA Topoisomerases, Type II/metabolism , Isoenzymes/metabolism , Mitosis , Phosphoproteins/metabolism , Protein Serine-Threonine Kinases/metabolism , Serine/metabolism , Amino Acid Sequence , Animals , Antigens, Neoplasm , Casein Kinase II , Catalysis , Cell Extracts , Chromosomes, Human , DNA Topoisomerases, Type II/chemistry , DNA-Binding Proteins , Guanosine Triphosphate/metabolism , HeLa Cells , Heparin/metabolism , Humans , Isoenzymes/antagonists & inhibitors , Isoenzymes/chemistry , Kinesins , Molecular Sequence Data , Phosphorylation , Sequence Homology, Amino Acid , Topoisomerase II InhibitorsABSTRACT
Disruption of Epstein-Barr virus (EBV) latency is mediated by ZEBRA, the protein product of the immediate-early EBV gene, BZLF1. In vitro, phorbol 12-myristate 13-acetate (PMA), a potent activator of protein kinase C (PKC), induces reactivation of EBV. However, the physiological stimuli responsible for the disruption of viral latency are not well characterized. Transforming growth factor beta 1 (TGF-beta1) has also been shown to trigger the reactivation of EBV in Burkitt lymphoma cell lines; however, the effect of TGF-beta1 on ZEBRA expression has not been reported. To further understand this phenomenon, we have investigated the effect of TGF-beta1 on ZEBRA expression. Our results indicate that the treatment of different EBV-positive Burkitt's lymphoma cell lines with TGF-beta1 induces a time-dependent activation of BZLF1 transcription with a corresponding increase in the production of the protein ZEBRA. TGF-beta1 has been shown to exert its effects through a wide range of intracellular routes; in the present study, we have explored these pathways. Transient expression of Smad proteins on their own had no effect on ZEBRA expression. A specific inhibitor of p38 mitogen-activated protein kinase (MAPK), SB203580, did not affect TGF-beta1-induced ZEBRA expression, whereas treatment with the MAPK/ERK kinase inhibitors, PD98059 and U0126, dramatically decreased this induction. This suggests that TGF-beta1 effect on BZLF1 expression requires the MAPK pathway. However, in Raji and B95-8 cells additional routes can be used, as (i) the inhibition of ZEBRA induction by PD98059 or U0126 was incomplete, whereas these inhibitors completely abolished PMA-induced ZEBRA expression, (ii) TGF-beta1 induction of ZEBRA expression occurs in PKC-depleted cells, (iii) in Raji and in B95-8 cells, the effect of TGF-beta1 and PMA are additive. Transient transfection of the EBV-negative B-cell line DG75 with a BZLF1 promoter-fusion construct (Zp-CAT) showed that under conditions where the BZLF1 promoter is activated by PMA treatment, TGF-beta1 had no significant effect on the expression of the chloramphenicol acetyltransferase gene. Furthermore, TGF-beta1 induction of BZLF1 transcripts is dependent on de novo protein synthesis, which suggests that TGF-beta1 induces BZLF1 expression by an indirect mechanism.
Subject(s)
DNA-Binding Proteins/genetics , Gene Expression Regulation, Viral/drug effects , Herpesvirus 4, Human/genetics , Immediate-Early Proteins/genetics , MAP Kinase Signaling System , Trans-Activators/genetics , Transforming Growth Factor beta/pharmacology , Viral Proteins , Butadienes/pharmacology , Calcium-Calmodulin-Dependent Protein Kinases/antagonists & inhibitors , Cyclic AMP-Dependent Protein Kinases/antagonists & inhibitors , DNA-Binding Proteins/biosynthesis , Enzyme Inhibitors/pharmacology , Flavonoids/pharmacology , Humans , Imidazoles/pharmacology , Immediate-Early Proteins/biosynthesis , Kinetics , Nitriles/pharmacology , Promoter Regions, Genetic , Protein Kinase C/antagonists & inhibitors , Pyridines/pharmacology , RNA, Messenger , Smad2 Protein , Smad3 Protein , Smad4 Protein , Smad7 Protein , Tetradecanoylphorbol Acetate/pharmacology , Trans-Activators/biosynthesis , Transforming Growth Factor beta/metabolism , Tumor Cells, CulturedABSTRACT
Among various other roles described so far, protein kinase CK2 has been involved in cell cycle, proliferation, and development. Here, we show that in response to specific stresses (heat shock or UV irradiation), a pool of the cellular CK2 content relocalizes in a particular nuclear fraction, increasing the activity of the kinase there. Electron microscopic analysis shows that upon heat shock, CK2alpha and CK2beta subunits are both detected in similar speckle structures occurring in the interchromatin space but are differentially targeted inside the nucleolus. This CK2 relocalization process takes place in a time- and dose-dependent manner and is reversible upon recovery at 37 degrees C. Altogether, this work suggests CK2 be involved in the response to physiological stress in higher eukaryotic cells.
Subject(s)
Cell Nucleolus/metabolism , Homeostasis , Protein Serine-Threonine Kinases/metabolism , 3T3 Cells , Animals , Biological Transport , Casein Kinase II , Cell Compartmentation , HeLa Cells , Hot Temperature , Humans , Mice , Oxidative Stress , Subcellular Fractions , Ultraviolet RaysABSTRACT
Epstein-Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC) generally occurs in adults, especially in high-prevalence populations such as the Chinese and Eskimos. In Maghrebian populations, young patients affected with this malignancy represent 25% of the total NPC cases. In adults with NPC, relatively high titers of IgA antibodies to the EBV viral capsid antigen (VCA) and early antigen (EA) represent important markers. However, nearly 50% of young NPC patients are negative for IgA-anti-VCA and -EA or exhibit very low titers of these antibodies. We report here that 92% of sera from young NPC patients negative for IgA-EA and 89% of those negative for IgA-VCA were positive for IgG antibodies to the EBV transactivator protein (ZEBRA) at very high titers. Our results show that in young patients with NPC these antibodies represent the most reliable marker for diagnosis and prognosis, particularly when compared with conventional NPC markers, i.e., IgA-VCA (58%) and anti-EA (25%). The titers of IgG-ZEBRA antibodies increased along with lymph node involvement only in the young patient group, suggesting a prognostic value of this marker in this patient group.
Subject(s)
Antibodies, Neoplasm/blood , Antibodies, Viral/blood , Biomarkers, Tumor/blood , DNA-Binding Proteins/immunology , Herpesvirus 4, Human/immunology , Nasopharyngeal Neoplasms/immunology , Nasopharyngeal Neoplasms/virology , Trans-Activators/immunology , Adolescent , Adult , Antibodies, Neoplasm/immunology , Antibodies, Viral/immunology , Antibody Specificity , Antigens, Viral/immunology , Biomarkers, Tumor/immunology , Capsid/immunology , Child , Child, Preschool , Female , Humans , Immunoglobulin A/blood , Immunoglobulin A/immunology , Immunoglobulin G/blood , Immunoglobulin G/immunology , Male , Nasopharyngeal Neoplasms/blood , Nasopharyngeal Neoplasms/pathology , Neoplasm Staging , Viral Proteins/immunologyABSTRACT
Calnexin was initially identified as an endoplasmic reticulum (ER) type I integral membrane protein, phosphorylated on its cytosolic domain by ER-associated protein kinases. Although the role of the ER luminal domain of calnexin has been established as a constituent of the molecular chaperone machinery of the ER, less is known about the role of the cytosolic phosphorylation of calnexin. Analysis by two-dimensional phosphopeptide maps revealed that calnexin was in vitro phosphorylated in isolated microsomes by casein kinase 2 (CK2) and extracellular-signal regulated kinase-1 (ERK-1) at sites corresponding to those for in vivo phosphorylation. In canine pancreatic microsomes, synergistic phosphorylation by CK2 and ERK-1 led to increased association of calnexin with membrane-bound ribosomes. In vivo, calnexin-associated ERK-1 activity was identified by co-immunoprecipitation. This activity was abolished in cells expressing a dominant-negative MEK-1. Activation of ERK-1 in cells by addition of serum led to a 4-fold increase in ribosome-associated calnexin over unstimulated cells. Taken together with studies revealing calnexin association with CK2 and ERK-1, a model is proposed whereby phosphorylation of calnexin leads to a potential increase in glycoprotein folding close to the translocon.
Subject(s)
Calcium-Binding Proteins/metabolism , Calcium-Calmodulin-Dependent Protein Kinases/metabolism , Mitogen-Activated Protein Kinase Kinases , Mitogen-Activated Protein Kinases , Protein Serine-Threonine Kinases/metabolism , Ribosomes/metabolism , Animals , Blood Proteins/pharmacology , Calnexin , Casein Kinase II , Cell Line , Cytosol/metabolism , Dogs , Endoplasmic Reticulum, Rough/drug effects , Endoplasmic Reticulum, Rough/enzymology , Endoplasmic Reticulum, Rough/metabolism , Enzyme Activation/drug effects , Intracellular Membranes/drug effects , Intracellular Membranes/enzymology , Intracellular Membranes/metabolism , MAP Kinase Kinase 1 , Microsomes/drug effects , Microsomes/enzymology , Microsomes/metabolism , Mitogen-Activated Protein Kinase 3 , Pancreas/cytology , Phosphorylation , Precipitin Tests , Protein Binding/drug effects , Protein Serine-Threonine Kinases/genetics , Protein-Tyrosine Kinases/genetics , Protein-Tyrosine Kinases/metabolism , Rats , Recombinant Fusion Proteins/metabolism , Ribosomes/drug effects , Serine/metabolismABSTRACT
Protein kinase CK2 is a tetramer composed of two alpha catalytic subunits and two beta regulatory subunits. The structure of a C-terminal truncated form of the human beta subunit has been determined by X-ray crystallography to 1.7 A resolution. One dimer is observed in the asymmetric unit of the crystal. The most striking feature of the structure is the presence of a zinc finger mediating the dimerization. The monomer structure consists of two domains, one entirely alpha-helical and one including the zinc finger. The dimer has a crescent shape holding a highly acidic region at both ends. We propose that this acidic region is involved in the interactions with the polyamines and/or catalytic subunits. Interestingly, conserved amino acid residues among beta subunit sequences are clustered along one linear ridge that wraps around the entire dimer. This feature suggests that protein partners may interact with the dimer through a stretch of residues in an extended conformation.
Subject(s)
Protein Serine-Threonine Kinases/chemistry , Zinc Fingers/physiology , Amino Acid Sequence , Binding Sites , Casein Kinase II , Conserved Sequence , Crystallization , Crystallography, X-Ray , Dimerization , Humans , Hydrogen Bonding , Models, Molecular , Molecular Sequence Data , Peptide Fragments/chemistry , Protein Binding , Protein Conformation , Protein Folding , Protein Serine-Threonine Kinases/metabolism , Protein Structure, Secondary , Sequence Alignment , Spermine/analogs & derivatives , Spermine/metabolism , Zinc/metabolismABSTRACT
We have characterized several subdomains of the beta subunit of protein kinase CK2. The N-terminal half of the protein exhibits a pseudo-substrate segment in tandem with a polyamine binding domain responsible for the activation of the kinase by these polybasic compounds. Study of the chemical features of this polyamine binding site showed that polyamine analogs exhibiting the highest affinity for CK2 are the best CK2 activators. Mutational analysis disclosed that glutamic residues lying in the polyacidic region of the CK2beta subunit are involved in the interaction with polyamine molecules and allowed the delineation of an autonomous binding domain. Furthermore, this regulatory domain was shown to mediate the association of CK2 with plasma membrane. The C-terminal domain of the CK2beta subunit plays a role in the oligomerization of the kinase since it was observed that a truncated form of this subunit lacking its 33-last amino acids was incompetent for the assembly of polymeric forms of CK2. Altogether, our results support the notion that the beta subunit of CK2 is a modular protein made by the association of interdependent domains that are involved in its multiple functions.