Signal transduction pathways in both prokaryotes and eukaryotes utilize protein phosphorylation as a key regulatory mechanism. Recent studies have proven that eukaryotic-type serine/threonine protein kinases (Hank's type) are widespread in many bacteria, although little is known regarding the cellular processes they control. In this study, we have attempted to establish the role of a single eukaryotic-type protein kinase, StkP of Streptococcus pneumoniae, in bacterial survival. Our results indicate that the expression of StkP is important for the resistance of S. pneumoniae to various stress conditions. To investigate the impact of StkP on this phenotype, we compared the whole-genome expression profiles of the wild-type and DeltastkP mutant strains by microarray technology. This analysis revealed that StkP positively controls the transcription of a set of genes encoding functions involved in cell wall metabolism, pyrimidine biosynthesis, DNA repair, iron uptake, and oxidative stress response. Despite the reduced transformability of the stkP mutant, we found that the competence regulon was derepressed in the stkP mutant under conditions that normally repress natural competence development. Furthermore, the competence regulon was expressed independently of exogenous competence-stimulating peptide. In summary, our studies show that a eukaryotic-type serine/threonine protein kinase functions as a global regulator of gene expression in S. pneumoniae.

• MeSH
• bakteriální proteiny genetika   metabolismus   MeSH
• delece genu MeSH
• eukaryotické buňky enzymologie   MeSH
• fenotyp MeSH
• financování organizované MeSH
• koncentrace vodíkových iontů MeSH
• mikrobiální viabilita genetika   účinky léků   MeSH
• mutace MeSH
• osmotický tlak MeSH
• oxidační stres MeSH
• peroxid vodíku farmakologie   MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• protein-serin-threoninkinasy genetika   metabolismus   MeSH
• regulace genové exprese u bakterií MeSH
• sekvenční analýza hybridizací s uspořádaným souborem oligonukleotidů MeSH
• Streptococcus pneumoniae enzymologie   genetika   růst a vývoj   MeSH
• testy genetické komplementace MeSH
• vysoká teplota MeSH

The silent information regulator 1 (Sirt1) has been shown to have negative effects on the Notch pathway in several contexts. We bring evidence that Sirt1 has a positive effect on Notch activation in Drosophila, in the context of sensory organ precursor specification and during wing development. The phenotype of Sirt1 mutant resembles weak Notch loss-of-function phenotypes, and genetic interactions of Sirt1 with the components of the Notch pathway also suggest a positive role for Sirt1 in Notch signalling. Sirt1 is necessary for the efficient activation of enhancer of split [E(spl)] genes by Notch in S2N cells. Additionally, the Notch-dependent response of several E(spl) genes is sensitive to metabolic stress caused by 2-deoxy-d-glucose treatment, in a Sirt1-dependent manner. We found Sirt1 associated with several proteins involved in Notch repression as well as activation, including the cofactor exchange factor Ebi (TBL1), the RLAF/LAF histone chaperone complex and the Tip60 acetylation complex. Moreover, Sirt1 participates in the deacetylation of the CSL transcription factor Suppressor of Hairless. The role of Sirt1 in Notch signalling is, therefore, more complex than previously recognized, and its diverse effects may be explained by a plethora of Sirt1 substrates involved in the regulation of Notch signalling.

• MeSH
• buněčné linie MeSH
• deoxyglukosa farmakologie   MeSH
• Drosophila MeSH
• hmotnostní spektrometrie MeSH
• imunoprecipitace MeSH
• messenger RNA antagonisté a inhibitory   MeSH
• proteiny Drosophily genetika   metabolismus   MeSH
• receptory Notch genetika   metabolismus   MeSH
• represorové proteiny genetika   metabolismus   MeSH
• RNA interference fyziologie   MeSH
• signální transdukce účinky léků   genetika   MeSH
• sirtuin 1 genetika   metabolismus   MeSH
• transkripční faktory bHLH genetika   metabolismus   MeSH
• vazba proteinů MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Fibroblast growth factor 21 (FGF21) is a novel metabolic regulator produced primarily by the liver that exerts potent antidiabetic and lipid-lowering effects in animal models of obesity and type 2 diabetes mellitus. This hormone contributes to body weight regulation and is strongly involved in the response to nutritional deprivation and ketogenic state in mice. The principal sites of metabolic actions of FGF21 are adipose tissue, liver and pancreas. Experimental studies have shown marked improvements in diabetes compensation and dyslipidemia after FGF21 administration in diabetic mice and primates. Positive metabolic actions of FGF21 without the presence of apparent side effects make this factor a hot candidate to treat type 2 diabetes and accompanying metabolic diseases. The aim of this review is to summarize the current knowledge about the metabolic effects of FGF21 including some preliminary data on changes of its levels in humans with a special emphasis on its therapeutic potential in type 2 diabetes mellitus.

• MeSH
• diabetes mellitus 2. typu farmakoterapie   metabolismus   MeSH
• energetický metabolismus účinky léků   MeSH
• fibroblastové růstové faktory metabolismus   terapeutické užití   účinky léků   MeSH
• financování organizované MeSH
• hypoglykemika škodlivé účinky   terapeutické užití   MeSH
• látky proti obezitě škodlivé účinky   terapeutické užití   MeSH
• lidé MeSH
• modely nemocí na zvířatech MeSH
• obezita farmakoterapie   metabolismus   MeSH
• signální transdukce účinky léků   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH

• MeSH
• hormonální substituční terapie MeSH
• hypofyzární nanismus genetika   terapie   MeSH
• klinická studie jako téma MeSH
• lékařská genetika MeSH
• lidský růstový hormon genetika   terapeutické užití   MeSH
• mutace genetika   MeSH
• neuroendokrinologie MeSH
• růst a vývoj genetika   MeSH
• vývojové poruchy u dětí genetika   terapie   MeSH
• Publikační typ
• příručky MeSH

• Konspekt
• Obecná genetika. Obecná cytogenetika. Evoluce
• NLK Obory
• pediatrie
• genetika, lékařská genetika
• endokrinologie

DNA strand breaks arise continuously as the result of intracellular metabolism and in response to a multitude of genotoxic agents. To overcome such challenges to genomic stability, cells have evolved genome surveillance pathways that detect and repair damaged DNA in a coordinated fashion. Here we identify the previously uncharacterized human protein Xip1 (C2orf13) as a novel component of the checkpoint response to DNA strand breaks. Green fluorescent protein-tagged Xip1 was rapidly recruited to sites of DNA breaks, and this accumulation was dependent on a novel type of zinc finger motif located in the C terminus of Xip1. The initial recruitment kinetics of Xip1 closely paralleled that of XRCC1, a central organizer of single strand break (SSB) repair, and its accumulation was both delayed and sustained when the detection of SSBs was abrogated by inhibition of PARP-1. Xip1 and XRCC1 stably interacted through recognition of CK2 phosphorylation sites in XRCC1 by the Forkhead-associated (FHA) domain of Xip1, and XRCC1 was required to maintain steady-state levels of Xip1. Moreover, Xip1 was phosphorylated on Ser-116 by ataxia telangiectasia-mutated in response to ionizing radiation, further underscoring the potential importance of Xip1 in the DNA damage response. Finally, depletion of Xip1 significantly decreased the clonogenic survival of cells exposed to DNA SSB- or double strand break-inducing agents. Collectively, these findings implicate Xip1 as a new regulator of genome maintenance pathways, which may function to organize DNA strand break repair complexes at sites of DNA damage.

• MeSH
• ATM protein MeSH
• DNA vazebné proteiny metabolismus   MeSH
• DNA-lyasa (apurinová nebo apyrimidinová) MeSH
• dvouřetězcové zlomy DNA * MeSH
• fosfoproteiny genetika   metabolismus   MeSH
• fosforylace MeSH
• jednořetězcové zlomy DNA * MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• nestabilita genomu * fyziologie   MeSH
• oprava DNA * fyziologie   MeSH
• posttranslační úpravy proteinů fyziologie   MeSH
• protein-serin-threoninkinasy metabolismus   MeSH
• proteiny buněčného cyklu metabolismus   MeSH
• terciární struktura proteinů genetika   MeSH
• zinkové prsty genetika   MeSH
• Check Tag
• lidé MeSH

Cytokinins (CKs) are well-established as important phytohormonal regulators of plant growth and development. An increasing number of studies have also revealed the function of these hormones in plant responses to biotic and abiotic stresses. While the function of certain CK classes, including trans-zeatin and isopentenyladenine-type CKs, have been studied in detail, the role of cis-zeatin-type CKs (cZs) in plant development and in mediating environmental interactions is less well defined. Here we provide a comprehensive summary of the current knowledge about abundance, metabolism and activities of cZs in plants. We outline the history of their analysis and the metabolic routes comprising cZ biosynthesis and degradation. Further we provide an overview of changes in the pools of cZs during plant development and environmental interactions. We summarize studies that investigate the role of cZs in regulating plant development and defence responses to pathogen and herbivore attack and highlight their potential role as 'novel' stress-response markers. Since the functional roles of cZs remain largely based on correlative data and genetic manipulations of their biosynthesis, inactivation and degradation are few, we suggest experimental approaches using transgenic plants altered in cZ levels to further uncover their roles in plant growth and environmental interactions and their potential for crop improvement.

• MeSH
• býložravci MeSH
• fyziologie rostlin * MeSH
• potravní řetězec * MeSH
• regulace genové exprese u rostlin * MeSH
• regulátory růstu rostlin metabolismus   MeSH
• vývoj rostlin MeSH
• zeatin metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Cultures of three-dimensional aggregates of embryonic stem cells (ESCs) called embryoid bodies (EBs) provide a valuable system for analyzing molecular mechanisms that regulate differentiation of this unique cell type. Cyclin-dependent kinase inhibitor p27Kip1 (p27) becomes elevated during the differentiation of mouse ESCs (mESCs). In this study, various aspects of differentiation of EBs produced from normal and p27-deficient mESCs were analyzed to address the biological significance of this elevation. It was found that EBs lacking p27 grew significantly bigger, but this was not accompanied by detect-able abnormalities in the activities of cyclin-dependent kinases (CDKs). In most EB cells, downregulation of activating cyclins rather than upregulation of inhibiting p27 is probably responsible for lowering the activity of their CDKs. Abnormalities in the development of specific cell lineages were also observed in p27-deficient EBs. These included elimination of cells positive for cytokeratin endo-A (TROMA-I) and increased proliferation and formation of cavities originating from cells positive for Lewis-X. Our data also suggest that although two different pools of Lewis-X-expressing cells, cluster forming (ESC-like) and cavity forming (neural progenitors), normally exist in EBs, the absence of p27 leads to the enhancement of only the neural pool. No failure was found when the neurogenic capacity of p27-deficient mESCs was tested using various protein markers. Together, our data point to a dual role of p27 in mESCs, with one role being in the regulation of proliferation and the other role in establishing some other aspects of a differentiated phenotype.

• MeSH
• antigen Lewis X metabolismus   MeSH
• buněčná diferenciace MeSH
• buněčný cyklus MeSH
• časové faktory MeSH
• down regulace MeSH
• embryo savčí fyziologie   MeSH
• fenotyp MeSH
• financování organizované MeSH
• fluorescenční mikroskopie MeSH
• imunohistochemie MeSH
• imunoprecipitace MeSH
• inhibitor p27 cyklin-dependentní kinasy MeSH
• kmenové buňky metabolismus   MeSH
• myši MeSH
• nádorové supresorové proteiny fyziologie   genetika   MeSH
• neurony metabolismus   MeSH
• proliferace buněk MeSH
• proteiny buněčného cyklu fyziologie   genetika   MeSH
• průtoková cytometrie MeSH
• upregulace MeSH
• viabilita buněk MeSH
• western blotting MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH

We studied how deficiency in lamins A/C and lamina-associated polypeptide 2α (Lap2α) affects DNA repair after irradiation. A-type lamins and Lap2α were not recruited to local DNA lesions and did not accumulate to γ-irradiation-induced foci (IRIF), as it is generally observed for well-known marker of DNA lesions, 53BP1 protein. At micro-irradiated chromatin of lmna double knockout (dn) and Lap2α dn cells, 53BP1 protein levels were reduced, compared to locally irradiated wild-type counterpart. Decreased levels of 53BP1 we also observed in whole populations of lmna dn and Lap2α dn cells, irradiated by UV light. We also studied distribution pattern of 53BP1 protein in a genome outside micro-irradiated region. In Lap2α deficient cells, identical fluorescence of mCherry-tagged 53BP1 protein was found at both microirradiated region and surrounding chromatin. However, a well-known marker of double strand breaks, γH2AX, was highly abundant in the lesion-surrounding genome of Lap2α deficient cells. Described changes, induced by irradiation in Lap2α dn cells, were not accompanied by cell cycle changes. In Lap2α dn cells, we additionally performed analysis by FLIM (Fluorescence Lifetime Imaging Microscopy) that showed different dynamic behavior of mCherry-tagged 53BP1 protein pools when it was compared with wild-type (wt) fibroblasts. This analysis revealed three different fractions of mCherry-53BP1 protein. Two of them showed identical exponential decay times (τ1 and τ3), but the decay rate of τ2 and amplitudes of fluorescence decays (A1-A3) were statistically different in wt and Lap2α dn fibroblasts. Moreover, γ-irradiation weakened an interaction between A-type lamins and Lap2α. Together, our results demonstrate how depletion of Lap2α affects DNA damage response (DDR) and how chromatin compactness is changed in Lap2α deficient cells exposed to radiation.

• MeSH
• 53BP1 genetika   metabolismus   MeSH
• chromatin chemie   účinky záření   ultrastruktura   MeSH
• DNA vazebné proteiny nedostatek   genetika   MeSH
• embryo savčí MeSH
• fibroblasty cytologie   metabolismus   účinky záření   MeSH
• FRAP MeSH
• histony genetika   metabolismus   MeSH
• lamin typ A nedostatek   genetika   MeSH
• luminescentní proteiny genetika   metabolismus   MeSH
• membránové proteiny nedostatek   genetika   MeSH
• myši MeSH
• oprava DNA * MeSH
• poškození DNA MeSH
• regulace genové exprese MeSH
• rekombinantní fúzní proteiny genetika   metabolismus   MeSH
• reportérové geny MeSH
• signální transdukce MeSH
• transformované buněčné linie MeSH
• ultrafialové záření MeSH
• záření gama MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Extra-cellular adenosine is an important regulator of inflammatory responses. It is generated from released ATP by a cascade of ectoenzymes and degraded by adenosine deaminase (ADA). There are two types of enzymes with ADA activity: ADA1 and ADGF/ADA2. ADA2 activity originates from macrophages and dendritic cells and is associated with inflammatory responses in humans and rats. Drosophila possesses a family of six ADGF proteins with ADGF-A being the main regulator of extra-cellular adenosine during larval stages. Herein we present the generation of a GFP reporter for ADGF-A expression by a precise replacement of the ADGF-A coding sequence with GFP using homologous recombination. We show that the reporter is specifically expressed in aggregating hemocytes (Drosophila immune cells) forming melanotic capsules; a characteristic of inflammatory response. Our vital reporter thus confirms ADA expression in sites of inflammation in vivo and demonstrates that the requirement for ADA activity during inflammatory response is evolutionary conserved from insects to vertebrates. Our results also suggest that ADA activity is achieved specifically within sites of inflammation by an uncharacterized post-transcriptional regulation based mechanism. Utilizing various mutants that induce melanotic capsule formation and also a real immune challenge provided by parasitic wasps, we show that the acute expression of the ADGF-A protein is not driven by one specific signaling cascade but is rather associated with the behavior of immune cells during the general inflammatory response. Connecting the exclusive expression of ADGF-A within sites of inflammation, as presented here, with the release of energy stores when the ADGF-A activity is absent, suggests that extra-cellular adenosine may function as a signal for energy allocation during immune response and that ADGF-A/ADA2 expression in such sites of inflammation may regulate this role.

• MeSH
• adenosindeaminasa metabolismus   MeSH
• DNA vazebné proteiny genetika   MeSH
• Drosophila melanogaster cytologie   enzymologie   imunologie   parazitologie   MeSH
• fosfoproteiny genetika   MeSH
• hemocyty cytologie   enzymologie   MeSH
• larva cytologie   genetika   MeSH
• messenger RNA genetika   metabolismus   MeSH
• mutace genetika   MeSH
• paraziti fyziologie   MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• proteiny Drosophily genetika   metabolismus   MeSH
• regulace genové exprese MeSH
• rekombinace genetická genetika   MeSH
• reportérové geny genetika   MeSH
• Southernův blotting MeSH
• sršňovití fyziologie   MeSH
• zánět enzymologie   imunologie   patologie   MeSH
• zelené fluorescenční proteiny genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

T cells are pivotal in the adaptive immune defense, necessitating a delicate balance between robust response against infections and self-tolerance. Their activation involves intricate cross-talk among signaling pathways triggered by the T-cell antigen receptors (TCR) and co-stimulatory or inhibitory receptors. The molecular regulation of these complex signaling networks is still incompletely understood. Here, we identify the adaptor protein ABIN1 as a component of the signaling complexes of GITR and OX40 co-stimulation receptors. T cells lacking ABIN1 are hyper-responsive ex vivo, exhibit enhanced responses to cognate infections, and superior ability to induce experimental autoimmune diabetes in mice. ABIN1 negatively regulates p38 kinase activation and late NF-κB target genes. P38 is at least partially responsible for the upregulation of the key effector proteins IFNG and GZMB in ABIN1-deficient T cells after TCR stimulation. Our findings reveal the intricate role of ABIN1 in T-cell regulation.

• MeSH
• adaptorové proteiny signální transdukční * metabolismus   genetika   MeSH
• aktivace lymfocytů imunologie   genetika   MeSH
• cytotoxické T-lymfocyty * imunologie   metabolismus   MeSH
• diabetes mellitus 1. typu imunologie   genetika   metabolismus   MeSH
• glukokortikoidy indukovaný protein související s TNRF MeSH
• interferon gama metabolismus   MeSH
• lidé MeSH
• mitogenem aktivované proteinkinasy p38 metabolismus   MeSH
• myši inbrední C57BL MeSH
• myši knockoutované MeSH
• myši MeSH
• NF-kappa B metabolismus   MeSH
• receptory antigenů T-buněk metabolismus   MeSH
• receptory OX40 metabolismus   genetika   MeSH
• signální transdukce * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH