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Summary: Canonical interleukin-2 (IL-2) signaling via the high-affinity CD25-containing IL-2 receptor-Janus kinase (JAK)1,3-signal transducer and activator of transcription 5 (STAT5) pathway is essential for development and maintenance of CD4+CD25HiFoxp3+ regulatory T cells (Tregs) that support immune homeostasis. Here, we report that IL-2 signaling via an alternative CD25-chemokine receptor pathway promotes the suppressive function of Tregs. Using an antibody against CD25 that biases IL-2 signaling toward this alternative pathway, we establish that this pathway increases the suppressive activity of Tregs and ameliorates murine experimental autoimmune encephalomyelitis (EAE). Furthermore, heparan sulfate, an IL-2-binding element of cell surfaces and extracellular matrix, or an engineered IL-2 immunocytokine can also direct IL-2 signaling toward this alternative pathway. Overall, these data reveal a non-canonical mechanism for IL-2 signaling that promotes suppressive functions of Tregs, further elucidates how IL-2 supports immune homeostasis, and suggests approaches to promote or suppress Treg functions.

Pathogenic intestinal bacteria lead to significant disease in humans. Here we investigated the role of the multifunctional protein, Apurinic/apyrimidinic endonuclease 1 (APE1), in regulating the internalization of bacteria into the intestinal epithelium. Intestinal tumor-cell lines and primary human epithelial cells were infected with Salmonella enterica serovar Typhimurium or adherent-invasive Escherichia coli. The effects of APE1 inhibition on bacterial internalization, the regulation of Rho GTPase Rac1 as well as the epithelial cell barrier function were assessed. Increased numbers of bacteria were present in APE1-deficient colonic tumor cell lines and primary epithelial cells. Activation of Rac1 was augmented following infection but negatively regulated by APE1. Pharmacological inhibition of Rac1 reversed the increase in intracellular bacteria in APE1-deficient cells whereas overexpression of constitutively active Rac1 augmented the numbers in APE1-competent cells. Enhanced numbers of intracellular bacteria resulted in the loss of barrier function and a delay in its recovery. Our data demonstrate that APE1 inhibits the internalization of invasive bacteria into human intestinal epithelial cells through its ability to negatively regulate Rac1. This activity also protects epithelial cell barrier function.

Summary: Cells perceive and respond to the extracellular matrix via integrin receptors; their dysregulation has been implicated in inflammation and cancer metastasis. Here we show that a guanine nucleotide-exchange modulator of trimeric-GTPase Gαi, GIV (a.k.a Girdin), directly binds the integrin adaptor Kindlin-2. A non-canonical short linear motif within the C terminus of GIV binds Kindlin-2-FERM3 domain at a site that is distinct from the binding site for the canonical NPxY motif on the -integrin tail. Binding of GIV to Kindlin-2 allosterically enhances Kindlin-2's affinity for β1-integrin. Consequently, integrin activation and clustering are maximized, which augments cell adhesion, spreading, and invasion. Findings elucidate how the GIV•Kindlin-2 complex has a 2-fold impact: it allosterically synergizes integrin activation and enables β1-integrins to indirectly access and modulate trimeric GTPases via the complex. Furthermore, Cox proportional-hazard models on tumor transcriptomics provide trans-scale evidence of synergistic interactions between GIV•Kindlin-2•β1-integrin on time to progression to metastasis.

The indole motif plays a significant role in the quest for innovative drugs. As proposed, novel N‐substituted indole derivatives were synthesized, and their efficacy against bacteria and fungi was evaluated in vitro. The synthesis of these compounds was confirmed using easily accessible building blocks, and their structural formulas were supported by corrected analytical and spectroscopic analyses. Fresh strains of Candida albicans, Escherichia coli, and Pseudomonas aeruginosa, as well as Bacillus subtilis and Staphylococcus aureus, were utilized to assess the antibacterial and antifungal activities. Notably, the derivatives 1‐(phenyl (piperidine‐1‐yl) methyl)‐1H‐indole and 4‐(1H‐indol‐1‐yl) (phenyl) morpholine have strong antifungal effects on Candida albicans that are equivalent to those of the widely used drug fluconazole. [ABSTRACT FROM AUTHOR]

The alkaline hydrolysis of carboxylate (1-naphthylbutyrate) and carbonate esters (2-(methylsulfonyl)-ethyl-4-nitrophenylcarbonate) in the presence of different surfactants has been studied. The rate of hydrolysis of these esters was determined under pseudo first order condition in which the concentration of NaOH was kept in large excess over the [ester]. The cationic micelles of cetyltrimethylammonium bromide (CTABr) and cetyltrimethylammonium sulfate ((CTA)2SO4) enhanced the rate of hydrolysis of esters to a maximum value and thereafter, the increasing concentration of surfactant decreased the reaction rate. The anionic micelles of sodium dodecyl sulfate (SDS) inhibited the rate of the hydrolysis. The reaction proceeds through the attack of OH− ions on the carbonyl carbon forming tetrahedral intermediate. The tetrahedral intermediate is unstable and collapses immediately to yield respective acid and alcohol. The micelles influence the stability of tetrahedral intermediate, in turn, altering the rate of hydrolysis. The variation in the rate of hydrolysis by micelles was treated by considering the pseudophase ion-exchange model and Menger–Portnoy model. The added salts viz. NaBr, NaCl, and LiCl inhibited the rate of the reaction in the presence of cationic and anionic micelles. The kinetic parameters i.e. km and Ks were determined from the rate–[surfactant] profile.

Tumor cell extravasation is a key step during cancer metastasis, yet the precise mechanisms that regulate this dynamic process are unclear. We utilized a high-resolution time-lapse intravital imaging approach to visualize the dynamics of cancer cell extravasation in vivo. During intravascular migration, cancer cells form protrusive structures identified as invadopodia by their enrichment of MT1-MMP, cortactin, Tks4, and importantly Tks5, which localizes exclusively to invadopodia. Cancer cells extend invadopodia through the endothelium into the extravascular stroma prior to their extravasation at endothelial junctions. Genetic or pharmacological inhibition of invadopodia initiation (cortactin), maturation (Tks5), or function (Tks4) resulted in an abrogation of cancer cell extravasation and metastatic colony formation in an experimental mouse lung metastasis model. This provides direct evidence of a functional role for invadopodia during cancer cell extravasation and distant metastasis and reveals an opportunity for therapeutic intervention in this clinically important process.

Generation of reactive oxygen species (ROS) during infection is an immediate host defense leading to microbial killing. APE1 is a multifunctional protein induced by ROS and after induction, protects against ROS-mediated DNA damage. Rac1 and NAPDH oxidase (Nox1) are important contributors of ROS generation following infection and associated with gastrointestinal epithelial injury. The purpose of this study was to determine if APE1 regulates the function of Rac1 and Nox1 during oxidative stress. Gastric or colonic epithelial cells (wild-type or with suppressed APE1) were infected with Helicobacter pylori or Salmonella enterica and assessed for Rac1 and NADPH oxidase-dependent superoxide production. Rac1 and APE1 interactions were measured by co-immunoprecipitation, confocal microscopy and proximity ligation assay (PLA) in cell lines or in biopsy specimens. Significantly greater levels of ROS were produced by APE1-deficient human gastric and colonic cell lines and primary gastric epithelial cells compared to control cells after infection with either gastric or enteric pathogens. H. pylori activated Rac1 and Nox1 in all cell types, but activation was higher in APE1 suppressed cells. APE1 overexpression decreased H. pylori-induced ROS generation, Rac1 activation, and Nox1 expression. We determined that the effects of APE1 were mediated through its N-terminal lysine residues interacting with Rac1, leading to inhibition of Nox1 expression and ROS generation. APE1 is a negative regulator of oxidative stress in the gastrointestinal epithelium during bacterial infection by modulating Rac1 and Nox1. Our results implicate APE1 in novel molecular interactions that regulate early stress responses elicited by microbial infections.

Reaction of 2-(aminomethyl)benzimidazole dihydrochloride (1) with ethyl acetoacetate was studied to give diazepinone-benzimidazole derivative (2), while, treatment of 1 with phenylhydrazono ethylacetoacetate afforded phenylhydrazino diazepinone derivative (3). On the other hand, reaction of 1 with acetyl acetone resulted in the formation of diazepine derivative (4). The reaction of 1 with ethyl cyanoacetate was studied to give 3-aminodiazepinone derivative (5). Also the reaction of 1 with acetophenone and/or benzophenone has been investigated to give the fused imidazolines 6 and 7 respectively, while the reaction of 1 with cyclopentanone gave benzimidazolyl derivative (8). Treatment of 1 with chloroacetyl chloride gave the fused pyrazinone (9). The treatment of 1 with benzoin gave the derivative (10). The structures of the hitherto unknown compounds have been confirmed from analytical and spectral data. The newly synthesized compounds were screened for antibacterial and antifungal activity.

The present study focuses on using the adsorption character of the layered double hydroxide (LDH) for removal of aromatics species because of its simple production, suitable for ecology, cost less and easy to modify by intercalation organic molecules which cause change from hydrophilic to hydrophobic character and help in increase the removal percentage of mono- and di- aromatics. In this work, nanolayered structures (AlZn NLS) were prepared and characterized by different techniques but cannot remove aromatics. After intercalation by organic molecules (4-aminobenzoic acid, Salicylic acid, Adipic acid and n -capric acid in order), series of AlZn nanohybrids were prepared and showed significant removal of mono- and di-aromatics. The prepared nanohybrids based on n -capric acid showed significant results for removal of both mono-aromatics (33.5%) and di-aromatics (28.6%). The current study concluded that the nanolayered structures of AlZn became effective for removal aromatic species because of the expansion of the interlayered spacing of nanolayers and the increase of hydrophobic character. [ABSTRACT FROM AUTHOR]

The analysis of dynamic events in the tumor microenvironment during cancer progression is limited by the complexity of current in vivo imaging models. This is coupled with an inability to rapidly modulate and visualize protein activity in real time and to understand the consequence of these perturbations in vivo. We developed an intravital imaging approach that allows the rapid induction and subsequent depletion of target protein levels within human cancer xenografts while assessing the impact on cell behavior and morphology in real time. A conditionally stabilized fluorescent E-cadherin chimera was expressed in metastatic breast cancer cells, and the impact of E-cadherin induction and depletion was visualized using real-time confocal microscopy in a xenograft avian embryo model. We demonstrate the assessment of protein localization, cell morphology and migration in cells undergoing epithelial-mesenchymal and mesenchymal-epithelial transitions in breast tumors. This technique allows for precise control over protein activity in vivo while permitting the temporal analysis of dynamic biophysical parameters.

Pathogenic intestinal bacteria lead to significant disease in humans. Here we investigated the role of the multifunctional protein, Apurinic/apyrimidinic endonuclease 1 (APE1), in regulating the internalization of bacteria into the intestinal epithelium. Intestinal tumor-cell lines and primary human epithelial cells were infected with Salmonella enterica serovar Typhimurium or adherent-invasive Escherichia coli. The effects of APE1 inhibition on bacterial internalization, the regulation of Rho GTPase Rac1 as well as the epithelial cell barrier function were assessed. Increased numbers of bacteria were present in APE1-deficient colonic tumor cell lines and primary epithelial cells. Activation of Rac1 was augmented following infection but negatively regulated by APE1. Pharmacological inhibition of Rac1 reversed the increase in intracellular bacteria in APE1-deficient cells whereas overexpression of constitutively active Rac1 augmented the numbers in APE1-competent cells. Enhanced numbers of intracellular bacteria resulted in the loss of barrier function and a delay in its recovery. Our data demonstrate that APE1 inhibits the internalization of invasive bacteria into human intestinal epithelial cells through its ability to negatively regulate Rac1. This activity also protects epithelial cell barrier function. [ABSTRACT FROM AUTHOR]

CD98, which is required for the rapid proliferation of both normal and cancer cells, and MET, the hepatocyte growth factor receptor, are potential targets for therapeutic antitumor Abs. In this study, we report that the antiproliferative activity of a prototype anti-CD98 Ab, UM7F8, is due to Ab-induced membrane-associated ring CH (MARCH) E3 ubiquitin ligase-mediated ubiquitination and downregulation of cell surface CD98. MARCH1-mediated ubiquitination of CD98 is required for UM7F8’s capacity to reduce CD98 surface expression and its capacity to inhibit the proliferation of murine T cells. Similarly, CD98 ubiquitination is required for UM7F8’s capacity to block the colony-forming ability of murine leukemia–initiating cells. To test the potential generality of the paradigm that MARCH E3 ligases can mediate the antiproliferative response to antitumor Abs, we examined the potential effects of MARCH proteins on responses to emibetuzumab, an anti-MET Ab currently in clinical trials for various cancers. We report that MET surface expression is reduced by MARCH1, 4, or 8-mediated ubiquitination and that emibetuzumab-induced MET ubiquitination contributes to its capacity to downregulate MET and inhibit human tumor cell proliferation. Thus, MARCH E3 ligases can act as cofactors for antitumor Abs that target cell surface proteins, suggesting that the MARCH protein repertoire of cells is a determinant of their response to such Abs. [ABSTRACT FROM AUTHOR]

This article pulls together and expands upon a range of key concepts and ideas that were first explored in two separate talks given by the writer highlighting the importance of intercultural ground in body and somatic psychotherapy. After speaking at the European Association for Body Psychotherapy (EABP) Congress in Berlin 2018 and then presenting an opening keynote speech at the United States Association for Body Psychotherapy (USABP) conference in California later that year, the writer explores macroscales of culture and multiculturalism, social and socioeconomic considerations, political cultures and microscales of signs, symbols, rhythms, creativity, societal symptoms, and embodiment, leading to the idea of intercultural ground. Throughout the writer attends to pitfalls and possibilities for both body and somatic psychotherapy, with a specific focus on organizational, practitioner, training, and supervisory levels in the context of the wider world. [ABSTRACT FROM AUTHOR]

Sometimes a patient's dependency and helplessness can feel unbearable. Learning to understand and tolerate these difficult feelings is vital for anyone involved in working with vulnerable people. It is important [...]

Generation of reactive oxygen species (ROS) during infection is an immediate host defense leading to microbial killing. APE1 is a multifunctional protein induced by ROS and after induction, protects against ROS-mediated DNA damage. Rac1 and NAPDH oxidase (Nox1) are important contributors of ROS generation following infection and associated with gastrointestinal epithelial injury. The purpose of this study was to determine if APE1 regulates the function of Rac1 and Nox1 during oxidative stress. Gastric or colonic epithelial cells (wild-type or with suppressed APE1) were infected with Helicobacter pylori or Salmonella enterica and assessed for Rac1 and NADPH oxidase-dependent superoxide production. Rac1 and APE1 interactions were measured by co-immunoprecipitation, confocal microscopy and proximity ligation assay (PLA) in cell lines or in biopsy specimens. Significantly greater levels of ROS were produced by APE1-deficient human gastric and colonic cell lines and primary gastric epithelial cells compared to control cells after infection with either gastric or enteric pathogens. H. pylori activated Rac1 and Nox1 in all cell types, but activation was higher in APE1 suppressed cells. APE1 overexpression decreased H. pylori-induced ROS generation, Rac1 activation, and Nox1 expression. We determined that the effects of APE1 were mediated through its N-terminal lysine residues interacting with Rac1, leading to inhibition of Nox1 expression and ROS generation. APE1 is a negative regulator of oxidative stress in the gastrointestinal epithelium during bacterial infection by modulating Rac1 and Nox1. Our results implicate APE1 in novel molecular interactions that regulate early stress responses elicited by microbial infections. [ABSTRACT FROM AUTHOR]

Summary Tumor cell extravasation is a key step during cancer metastasis, yet the precise mechanisms that regulate this dynamic process are unclear. We utilized a high-resolution time-lapse intravital imaging approach to visualize the dynamics of cancer cell extravasation in vivo. During intravascular migration, cancer cells form protrusive structures identified as invadopodia by their enrichment of MT1-MMP, cortactin, Tks4, and importantly Tks5, which localizes exclusively to invadopodia. Cancer cells extend invadopodia through the endothelium into the extravascular stroma prior to their extravasation at endothelial junctions. Genetic or pharmacological inhibition of invadopodia initiation (cortactin), maturation (Tks5), or function (Tks4) resulted in an abrogation of cancer cell extravasation and metastatic colony formation in an experimental mouse lung metastasis model. This provides direct evidence of a functional role for invadopodia during cancer cell extravasation and distant metastasis and reveals an opportunity for therapeutic intervention in this clinically important process. [ABSTRACT FROM AUTHOR]

Summary: Overcoming the cellular type I interferon (IFN) host defense response is critical for a virus to ensure successful infection. Investigating the effects of human adenovirus (HAdV) infection on global cellular histone posttranslational modification (hPTM), we discovered that virus infection-induced activation of IFN signaling triggers a global increase in the monoubiquitination of histone 2B (H2B) at lysine 120, which is a mark for transcriptionally active chromatin. This hPTM, catalyzed by the hBre1/RNF20 complex, is necessary for activation of the cellular IFN-stimulated gene (ISG) expression program in response to viruses. To establish effective infection, the HAdV E1A protein binds to and dissociates the hBre1 complex to block IFN-induced H2B monoubiquitination and associated ISG expression. Together, these data uncover a key role for H2B monoubiquitination in the type I IFN response and a viral mechanism of antagonizing this hPTM to evade the IFN response. [Copyright &y& Elsevier]

The analysis of dynamic events in the tumor microenvironment during cancer progression is limited by the complexity of current in vivo imaging models. This is coupled with an inability to rapidly modulate and visualize protein activity in real time and to understand the consequence of these perturbations in vivo. We developed an intravital imaging approach that allows the rapid induction and subsequent depletion of target protein levels within human cancer xenografts while assessing the impact on cell behavior and morphology in real time. A conditionally stabilized fluorescent E-cadherin chimera was expressed in metastatic breast cancer cells, and the impact of E-cadherin induction and depletion was visualized using real-time confocal microscopy in a xenograft avian embryo model. We demonstrate the assessment of protein localization, cell morphology and migration in cells undergoing epithelial-mesenchymal and mesenchymal-epithelial transitions in breast tumors. This technique allows for precise control over protein activity in vivo while permitting the temporal analysis of dynamic biophysical parameters. [ABSTRACT FROM AUTHOR]

Reaction of 2-(aminomethyl)benzimidazole dihydrochloride (1) with ethyl acetoacetate was studied to give diazepinone-benzimidazole derivative (2), while, treatment of 1 with phenylhydrazono ethylacetoacetate afforded phenylhydrazino diazepinone derivative (3). On the other hand, reaction of 1 with acetyl acetone resulted in the formation of diazepine derivative (4). The reaction of 1 with ethyl cyanoacetate was studied to give 3- aminodiazepinone derivative (5). Also the reaction of 1 with acetophenone and/or benzophenone has been investigated to give the fused imidazolines 6 and 7 respectively, while the reaction of 1 with cyclopentanone gave benzimidazolyl derivative (8). Treatment of 1 with chloroacetyl chloride gave the fused pyrazinone (9). The treatment of 1 with benzoin gave the derivative (10). The structures of the hitherto unknown compounds have been confirmed from analytical and spectral data. The newly synthesized compounds were screened for antibacterial and antifungal activity. [ABSTRACT FROM AUTHOR]

Abstract: The conserved region 3 (CR3) portion of the human adenovirus (HAdV) 5 E1A protein functions as a potent transcriptional activator that induces expression of viral early genes during infection. Expression of HAdV-5 CR3 in the yeast Saccharomyces cerevisiae inhibits growth, as do the corresponding regions of the HAdV-3, 4, 9, 12 and 40 E1A proteins, which represent the remaining five HAdV subgroups. Growth inhibition is alleviated by disruption of the SAGA transcriptional regulatory complex, suggesting that CR3 targets the yeast SAGA complex. In yeast, transcriptional activation by several, but not all, of the CR3 regions requires the Gcn5 acetyltransferase component of SAGA. The CR3 regions of HAdV-3, 5, 9 and 40, but not HAdV-4 and 12 interact with the pCAF acetyltransferase, a mammalian ortholog of yeast Gcn5. Disruption of the previously described N-terminal pCAF binding site abrogates binding by the HAdV-5 243R E1A protein, but not the larger 289R E1A protein, which is otherwise identical except for the presence of CR3. RNA interference directed against pCAF decreased HAdV-5 CR3 dependent transcriptional activation in mammalian cells. Our results identify a second independent binding site for pCAF in E1A and suggest that it contributes to CR3 dependent transcriptional activation. [Copyright &y& Elsevier]

This article explores the intersections between culture and trauma. In particular it focuses on the Black woman to Black woman client and therapist relationship. The roles of diversity and synthesis are explored in the therapeutic relationship, highlighting the author's approach as a body psychotherapist to working with the somatic trauma of the client and the somatic resonance of the therapist. Particular attention is paid to different ways of working with rage and the client's need to establish enough internal ground to face the trauma. The article allows the reader to share some of the experience of both the traumatised client and her journey, and the therapist's journey, in supporting the client towards health. The article also explores the meaning and working with ancestry as a necessary part of the therapeutic process. Additionally, the article provides some key points of learning for psychotherapists, trainers and supervisors about working with clients, trainees and supervisees different to oneself. Joanne Ablack explore dans cet article, les intersections entre culture et traumatisme. Elle se concentre en particulier sur la femme noire et sur la relation de la femme noire et du thérapeute. Les rôles respectifs de la diversité et de la synthèse sont explorés dans la relation thérapeutique, mettant en valeur son approche de thérapeute du corps, qui travaille avec le traumatisme somatique du client et la résonance somatique du thérapeute. Elle s'interroge particulìerement sur les différentes possibilités de travail avec la rage et sur le besoin des clients d'établire suffisamment d'espace interne pour faire face au traumatisme. Cet article permet au lecteur de partager certaines expériences de la cliente traumatisée et de son voyage ainsi que de celui du thérapeute qui soutient la cliente dans son voyage vers la santé. Ablack explore aussi le sens et le fonctionnement du lignage comme partie intégrale du processus thérapeutique. L'article fournit en plus certains points pédagogiques clés pour les psychothérapeutes, les formateurs et les superviseurs en ce qui concerne leur travail avec des clients, des gens en formation et en supervision, qui sont différents d'eux. In diesem Artikel untersucht Joanne Ablack die Schnittpunkte zwischen Kultur und Trauma. Sie konzentriert sich speziell auf die schwarze Frau und das Verhältnis Patient schwarze Frau und Therapeut. Die Rollen von Verschiedenheit und Synthese werden in der therapeutischen Beziehung unter Hervorhebung ihrer Annäherung als Körper-Psychotherapeutin an die Arbeit mit dem somatischen Trauma des Patienten und der somatischen Resonanz des Therapeuten untersucht. Spezielle Aufmerksamkeit erhalten hierbei die verschiedenen Wege der Arbeit mit Wut und das Bedürfnis des Patienten nach genügend innerem Raum, um das Trauma anzugehen.Der Artikel erlaubt es dem Leser, einige der Erfahrungen sowohl der traumatisierten Patientin und ihrem Weg der Heilung als auch die Unterstützung des Therapeuten auf diesem Weg zu teilen. Ablack untersucht des weiteren die Bedeutung von und Arbeit mit Abstammung als einen bedeutenden Teil des therapeutischen Prozesses.Zusätzlich enthält der Artikel einige Schlüsselpunkte betreffend das Lernen von Psychotherapeuten, Ausbildern und Vorgesetzten über die Arbeit mit Patienten, Ausbildern und Vorgesetzten, die anders als man selbst sind. [ABSTRACT FROM AUTHOR]

CD98 heavy chain (SLC3A2) facilitates lymphocyte clonal expansion that enables adaptive immunity; however, increased expression of CD98 is also a feature of both lymphomas and leukemias and represents a potential therapeutic target in these diseases. CD98 is transcriptionally regulated and ectopic expression of the membrane-associated RING-CH (MARCH) E3 ubiquitin ligases MARCH1 or MARCH8 leads to ubiquitylation and lysosomal degradation of CD98. Here, we examined the potential role of ubiquitylation in regulating CD98 expression and cell proliferation. We report that blocking ubiquitylation by use of a catalytically inactive MARCH or by creating a ubiquitylation-resistant CD98 mutant, prevents MARCH-induced CD98 downregulation in HeLa cells. March1-null T cells display increased CD98 expression. Similarly, T cells expressing ubiquitylation-resistant CD98 manifest increased proliferation in vitro and clonal expansion in vivo. Thus, ubiquitylation and the resulting downregulation of CD98 can limit cell proliferation and clonal expansion. [ABSTRACT FROM AUTHOR]

The largest isoform of adenovirus early region 1A (E1A) contains a unique region termed conserved region 3 (CR3). This region activates viral gene expression by recruiting cellular transcription machinery to the early viral promoters. Recent studies have suggested that there is an optimal level of E1A-dependent transactivation required by human adenovirus (hAd) during infection and that this may be achieved via functional cross talk between the N termini of E1A and CR3. The N terminus of E1A binds GCN5, a cellular lysine acetyltransferase (KAT). We have identified a second independent interaction of E1A with GCN5 that is mediated by CR3, which requires residues 178 to 188 in hAd5 E1A. GCN5 was recruited to the viral genome during infection in an E1A-dependent manner, and this required both GCN5 interaction sites on E1A. Ectopic expression of GCN5 repressed transactivation by both E1A CR3 and full-length E1A. In contrast, RNA interference (RNAi) depletion of GCN5 or treatment with the KAT inhibitor cyclopentylidene-[4-(4'-chlorophenyl)thiazol-2-yl]hydrazone (CPTH2) resulted in increased E1A CR3 transactivation. Moreover, activation of the adenovirus E4 promoter by E1A was increased during infection of homozygous GCN5 KAT-defective (hat/hat) mouse embryonic fibroblasts (MEFs) compared to wild-type control MEFs. Enhanced histone H3 K9/K14 acetylation at the viral E4 promoter required the newly identified binding site for GCN5 within CR3 and correlated with repression and reduced occupancy by phosphorylated RNA polymerase II. Treatment with CPTH2 during infection also reduced virus yield. These data identify GCN5 as a new negative regulator of transactivation by E1A and suggest that its KAT activity is required for optimal virus replication. [ABSTRACT FROM AUTHOR]

Pannexin 1 (Panx1) is a channel-forming glycoprotein expressed in different cell types of mammalian skin. We examined the role of Panx1 in melanoma tumorigenesis and metastasis since qPCR and Western blots revealed that mouse melanocytes exhibited low levels of Panx1 while increased Panx1 expression was correlated with tumor cell aggressiveness in the isogenic melanoma cell lines (B16-F0, -F10, and -BL6). Panx1 shRNA knockdown (Panx1-KD) generated stable BL6 cell lines, with reduced dye uptake, that showed a marked increase in melanocyte- like cell characteristics including higher melanin production, decreased cell migration and enhanced formation of cellular projections. Western blotting and proteomic analyses using 2D-gel/mass spectroscopy identified vimentin and β-catenin as two of the markers of malignant melanoma that were down-regulated in Panx1-KD cells. Xenograft Panx1-KD cells grown within the chorioallantoic membrane of avian embryos developed tumors that were significantly smaller than controls. Mouse-Alu qPCR of the excised avian embryonic organs revealed that tumor metastasis to the liver was significantly reduced upon Panx1 knockdown. These data suggest that while Panx1 is present in skin melanocytes it is up-regulated during melanoma tumor progression, and tumorigenesis can be inhibited by the knockdown of Panx1 raising the possibility that Panx1 may be a viable target for the treatment of melanoma. [ABSTRACT FROM AUTHOR]

Abstract: Proteasomes represent the major non-lysosomal mechanism responsible for the degradation of proteins. Following interferon γ treatment 3 proteasome subunits are replaced producing immunoproteasomes. Adenovirus E1A interacts with components of the 20S and 26S proteasome and can affect presentation of peptides. In light of these observations we investigated the relationship of AdE1A to the immunoproteasome. AdE1A interacts with the immunoproteasome subunit, MECL1. In contrast, AdE1A binds poorly to the proteasome β2 subunit which is replaced by MECL1 in the conversion of proteasomes to immunoproteasomes. Binding sites on E1A for MECL1 correspond to the N-terminal region and conserved region 3. Furthermore, AdE1A causes down-regulation of MECL1 expression, as well as LMP2 and LMP7, induced by interferon γ treatment during Ad infections or following transient transfection. Consistent with previous reports AdE1A reduced IFNγ-stimulated STAT1 phosphorylation which appeared to be responsible for its ability to reduce expression of immunoproteasome subunits. [Copyright &y& Elsevier]