Unanchored K48-Linked Polyubiquitin Synthesized by the E3-Ubiquitin Ligase TRIM6 Stimulates the Interferon-IKKε Kinase-Mediated Antiviral Response.

Type I interferons (IFN-I) are essential antiviral cytokines produced upon microbial infection. IFN-I elicits this activity through the upregulation of hundreds of IFN-I-stimulated genes (ISGs). The full breadth of ISG induction demands activation of a number of cellular factors including the IκB kinase epsilon (IKKε). However, the mechanism of IKKε activation upon IFN receptor signaling has remained elusive. Here we show that TRIM6, a member of the E3-ubiquitin ligase tripartite motif (TRIM) family of proteins, interacted with IKKε and promoted induction of IKKε-dependent ISGs. TRIM6 and the E2-ubiquitin conjugase UbE2K cooperated in the synthesis of unanchored K48-linked polyubiquitin chains, which activated IKKε for subsequent STAT1 phosphorylation. Our work attributes a previously unrecognized activating role of K48-linked unanchored polyubiquitin chains in kinase activation and identifies the UbE2K-TRIM6-ubiquitin axis as critical for IFN signaling and antiviral response

The combined effect of two mutations that alter serially homologous color pattern elements on the fore and hindwings of a butterfly

<p>Abstract</p> <p>Background</p> <p>The ability for serially homologous structures to acquire a separate identity has been primarily investigated for structures dependent on Hox gene input but is still incompletely understood in other systems. The fore and hindwings of butterflies are serially homologous structures as are the serially homologous eyespots that can decorate each of these wings. Eyespots can vary in number between fore and hindwings of the same individual and mutations of large effect can control the total number of eyespots that each of the wings displays. Here we investigate the genetics of a new spontaneous color pattern mutation, <it>Missing</it>, that alters eyespot number in the nymphalid butterfly, <it>Bicyclus anynana</it>. We further test the interaction of <it>Missing </it>with a previously described mutation, <it>Spotty</it>, describe the developmental stage affected by <it>Missing</it>, and test whether <it>Missing </it>is a mutant variant of the gene <it>Distal-less </it>via a linkage association study.</p> <p>Results</p> <p><it>Missing </it>removes or greatly reduces the size of two of the hindwing eyespots from the row of seven eyespots, with no detectable effect on the rest of the wing pattern. Offspring carrying a single <it>Missing </it>allele display intermediate sized eyespots at these positions. <it>Spotty </it>has the opposite effect of <it>Missing</it>, i.e., it introduces two extra eyespots in homologous wing positions to those affected by <it>Missing</it>, but on the forewing. When <it>Missing </it>is combined with <it>Spotty </it>the size of the two forewing eyespots decreases but the size of the hindwing spots stays the same, suggesting that these two mutations have a combined effect on the forewing such that <it>Missing </it>reduces eyespot size when in the presence of a <it>Spotty </it>mutant allele, but that <it>Spotty </it>has no effect on the hindwing. <it>Missing </it>prevents the complete differentiation of two of the eyespot foci on the hindwing. We found no evidence for any linkage between the <it>Distal-less </it>and <it>Missing </it>genes.</p> <p>Conclusion</p> <p>The spontaneous mutation <it>Missing </it>controls the differentiation of the signaling centers of a subset of the serial homologous eyespots present on both the fore and the hindwing in a dose-dependent fashion. The effect of <it>Missing </it>on the forewing, however, is only observed when the mutation <it>Spotty </it>introduces additional eyespots on this wing. <it>Spotty</it>, on the other hand, controls the differentiation of eyespot centers only on the forewing. <it>Spotty</it>, unlike <it>Missing</it>, may be under Ubx gene regulation, since it affects a subset of eyespots on only one of the serially homologous wings.</p

Nonmarital childbearing in Russia: second demographic transition or pattern of disadvantage?

Using retrospective union, birth, and education histories that span 1980-2003, this study investigates nonmarital childbearing in contemporary Russia. We employ a combination of methods to decompose fertility rates by union status and analyze the processes that lead to a nonmarital birth. We find that the increase in the percentage of nonmarital births was driven mainly by the growing proportion of women who cohabit before conception, not changing fertility behavior of cohabitors or changes in union behavior after conception. The relationship between education and nonmarital childbearing has remained stable: the least-educated women have the highest birth rates within cohabitation and as single mothers, primarily because of their lower probability of legitimating a nonmarital conception. These findings suggest that nonmarital childbearing Russia has more in common with the pattern of disadvantage in the United States than with the second demographic transition. We also find several aspects of nonmarital childbearing that neither of these perspectives anticipates

Analysis of in vivo dynamics of influenza virus infection using a GFP reporter virus.

Influenza A virus Is being extensively studied due to its major Impact in human and animal health. However, the dynamics of Influenza virus Infection and the cell types infected In vivo are poorly understood. These characteristics are not easy to determine parUy because currently there Is no replication-competent virus expressing a fluorescent reporter gene. Here, we report the generation of a complete Influenza virus carrying a GFP reporter gene In the NS segment of its genome (NS1-GFP virus). NS1-GFP virus replicates efficiently in cell culture and shows pathogenicity In mice at levels similar to parental virus. We have analyzed the In vivo dynamics of influenza Infection progression in mice by flow cytometry and whole organ Imaging of infected lungs. Using flow cytometric analysis of infected lungs, apart from epithelial cells, we find antigen presenting cells like CD11c+, CD11b+ CD11c+, CD11b+ and B cells to be GFP positive. In addition, NK cells are susceptible to Influenza Infection. Whole organ imaging of lungs show that influenza infection starts In the respiratory tract In areas closer to large conducting airways and with time spreads to deeper sections of the lungs. We have also tested the effects of oseltamivir and amantadine on the kinetics and In vivo infection progression in mice and find Interesting differences In the effects of these antivirals. Treatment with oseltamlvlr dramatically reduces Influenza Infection in all cell types, whereas, Interestingly, amantadine treatment blocks infection In a cell type specific manner

Inhibition of the Type I Interferon Response in Human Dendritic Cells by Dengue Virus Infection Requires a Catalytically Active NS2B3 Complex ▿ † §

Dengue virus (DENV) is the most prevalent arthropod-borne human virus, able to infect and replicate in human dendritic cells (DCs), inducing their activation and the production of proinflammatory cytokines. However, DENV can successfully evade the immune response in order to produce disease in humans. Several mechanisms of immune evasion have been suggested for DENV, most of them involving interference with type I interferon (IFN) signaling. We recently reported that DENV infection of human DCs does not induce type I IFN production by those infected DCs, impairing their ability to prime naive T cells toward Th1 immunity. In this article, we report that DENV also reduces the ability of DCs to produce type I IFN in response to several inducers, such as infection with other viruses or exposure to Toll-like receptor (TLR) ligands, indicating that DENV antagonizes the type I IFN production pathway in human DCs. DENV-infected human DCs showed a reduced type I IFN response to Newcastle disease virus (NDV), Sendai virus (SeV), and Semliki Forest virus (SFV) infection and to the TLR3 agonist poly(I:C). This inhibitory effect is DENV dose dependent, requires DENV replication, and takes place in DENV-infected DCs as early as 2 h after infection. Expressing individual proteins of DENV in the presence of an IFN-α/β production inducer reveals that a catalytically active viral protease complex is required to reduce type I IFN production significantly. These results provide a new mechanism by which DENV evades the immune system in humans

Budding Capability of the Influenza Virus Neuraminidase Can Be Modulated by Tetherin▿

We have determined that, in addition to its receptor-destroying activity, the influenza virus neuraminidase is capable of efficiently forming virus-like particles (VLPs) when expressed individually from plasmid DNA. This observation applies to both human subtypes of neuraminidase, N1 and N2. However, it is not found with every strain of influenza virus. Through gain-of-function and loss-of-function analyses, a critical determinant within the neuraminidase ectodomain was identified that contributes to VLP formation but is not sufficient to accomplish release of plasmid-derived VLPs. This sequence lies on the plasma membrane-proximal side of the neuraminidase globular head. Most importantly, we demonstrate that the antiviral restriction factor tetherin plays a role in determining the strain-specific limitations of release competency. If tetherin is counteracted by small interfering RNA knockdown or expression of the HIV anti-tetherin factor vpu, budding and release capability is bestowed upon an otherwise budding-deficient neuraminidase. These data suggest that budding-competent neuraminidase proteins possess an as-yet-unidentified means of counteracting the antiviral restriction factor tetherin and identify a novel way in which the influenza virus neuraminidase can contribute to virus release

La Piedad Michoacán Mexico Virus V protein antagonizes type I interferon response by binding STAT2 protein and preventing STATs nuclear translocation

La Piedad Michoacán Mexico Virus (LPMV) is a member of the Rubulavirus genus within the Paramyxoviridae family. LPMV is the etiologic agent of "blue eye disease", causing a significant disease burden in swine in Mexico with long-term implications for the agricultural industry. This virus mainly affects piglets and is characterized by meningoencephalitis and respiratory distress. It also affects adult pigs, causing reduced fertility and abortions in females, and orchitis and epididymitis in males. Viruses of the Paramyxoviridae family evade the innate immune response by targeting components of the interferon (IFN) signaling pathway. The V protein, expressed by most paramyxoviruses, is a well-characterized IFN signaling antagonist. Until now, there were no reports on the role of the LPMV-V protein in inhibiting the IFN response. In this study we demonstrate that LPMV-V protein antagonizes type I but not type II IFN signaling by binding STAT2, a component of the type I IFN cascade. Our results indicate that the last 18 amino acids of LPMV-V protein are required for binding to STAT2 in human and swine cells. While LPMV-V protein does not affect the protein levels of STAT1 or STAT2, it does prevent the IFN-induced phosphorylation and nuclear translocation of STAT1 and STAT2 thereby inhibiting cellular responses to IFN α/β

La Piedad Michoacán Mexico Virus V protein antagonizes type I interferon response by binding STAT2 protein and preventing STATs nuclear translocation.

La Piedad Michoacán Mexico Virus (LPMV) is a member of the Rubulavirus genus within the Paramyxoviridae family. LPMV is the etiologic agent of "blue eye disease", causing a significant disease burden in swine in Mexico with long-term implications for the agricultural industry. This virus mainly affects piglets and is characterized by meningoencephalitis and respiratory distress. It also affects adult pigs, causing reduced fertility and abortions in females, and orchitis and epididymitis in males. Viruses of the Paramyxoviridae family evade the innate immune response by targeting components of the interferon (IFN) signaling pathway. The V protein, expressed by most paramyxoviruses, is a well-characterized IFN signaling antagonist. Until now, there were no reports on the role of the LPMV-V protein in inhibiting the IFN response. In this study we demonstrate that LPMV-V protein antagonizes type I but not type II IFN signaling by binding STAT2, a component of the type I IFN cascade. Our results indicate that the last 18 amino acids of LPMV-V protein are required for binding to STAT2 in human and swine cells. While LPMV-V protein does not affect the protein levels of STAT1 or STAT2, it does prevent the IFN-induced phosphorylation and nuclear translocation of STAT1 and STAT2 thereby inhibiting cellular responses to IFN α/β