Inhibition of cellular protein secretion by norwalk virus nonstructural protein p22 requires a mimic of an endoplasmic reticulum export signal.

Protein trafficking between the endoplasmic reticulum (ER) and Golgi apparatus is central to cellular homeostasis. ER export signals are utilized by a subset of proteins to rapidly exit the ER by direct uptake into COPII vesicles for transport to the Golgi. Norwalk virus nonstructural protein p22 contains a YXΦESDG motif that mimics a di-acidic ER export signal in both sequence and function. However, unlike normal ER export signals, the ER export signal mimic of p22 is necessary for apparent inhibition of normal COPII vesicle trafficking, which leads to Golgi disassembly and antagonism of Golgi-dependent cellular protein secretion. This is the first reported function for p22. Disassembly of the Golgi apparatus was also observed in cells replicating Norwalk virus, which may contribute to pathogenesis by interfering with cellular processes that are dependent on an intact secretory pathway. These results indicate that the ER export signal mimic is critical to the antagonistic function of p22, shown herein to be a novel antagonist of ER/Golgi trafficking. This unique and well-conserved human norovirus motif is therefore an appealing target for antiviral drug development

Use of feedback to improve institutional staff performance

The following study assessed the effectiveness of two simple and inexpensive performance feedback conditions in improving the job performance of institutional staff. Participants were care staff employed at a large center for the developmenta1ly disabled. During two 3 week sessions participants from two separate treatment units received publicly posted feedback graphs with either their own personal names or self-chosen anonymous codes to designate whose graphs were whose. These graphs were posted in each unit\u27s training room and depicted participant performance (use of rewards and prompts) during behavioral training sessions with developmentally disabled clients. These two conditions were investigated to determine whether designation by proper name is important in the effectiveness of public feedback. It was hypothesized that the use of personal names would have a greater effect than anonymously coded feedback. Results indicated that only one participant\u27s performance improved during the personal name condition. For the same participant there was a decrease in performance during the subsequent anonymous code condition. For the other 5 participants, neither of the two feedback conditions were successful in improving their performance

Digital exclusion: implications for human services practitioners

Issues around digital exclusion may be in their infancy but they are developing fast. The Internet has the potential to offer equity of digital access for enabling individual independence and empowerment in an increasingly digital society. However, for many users of assistive technologies, this remains a problematic scenario. Citizens, who already experience disablement through social failure to recognize difference and diversity of need, may be doubly disabled by exclusive digital policy and practice. There is an urgent need to research the implications of this exclusion for human service educators and practitioners

Rotavirus-Induced Lipid Droplet Biogenesis Is Critical for Virus Replication

A variety of pathogens, including viruses, bacteria and parasites, target cellular lipid droplets for their replication. Rotaviruses (RVs) infect the villous epithelium of the small intestine and are a major cause of acute gastroenteritis in infants and young children worldwide. RVs induce and require lipid droplets for the formation of viroplasms, sites of virus genome replication, and nascent particle assembly. Here we review the role of lipid droplets in RV replication. Inhibitors of fatty acid synthesis or chemicals that interfere with lipid droplet homeostasis decrease the number and size of viroplasms and the yield of infectious virus. We used a genetically engineered RV, delayed in viroplasm assembly, to show an early interaction of RV nonstructural protein NSP2 and the lipid droplet-associated protein phospho-PLIN1. The interaction between NSP2 and phospho-PLIN1 suggests that we have identified part of the mechanism of RV-induced lipid droplet formation. These studies demonstrate that RV is an excellent model to dissect the cellular process of lipid droplet formation and to determine how RV induces and usurps lipid droplet biogenesis to form viroplasm/lipid droplets for virus replication

Plasmid-Based Reverse Genetics for Probing Phosphorylation-Dependent Viroplasm Formation in Rotaviruses

Rotavirus (RV) replication occurs in cytoplasmic compartments, known as viroplasms, that are composed of viral and cellular proteins. Viroplasm formation requires RV nonstructural proteins NSP2 and NSP5 and cellular lipid droplets (LDs); however, the mechanisms required for viroplasm assembly remain largely unknown. We previously identified two conformationally-distinct forms of NSP2 (dNSP2, vNSP2) found in RV-infected cells that interact differentially with hypo- and hyperphosphorylated NSP5, respectively, and indicate a coordinated phosphorylation-dependent mechanism regulating viroplasm assembly. We also reported that phosphorylation of dNSP2 on serine 313 by the cellular kinase CK1α triggers the localization of vNSP2 to sites of viroplasm assembly and its association with hyperphosphorylated NSP5. To directly evaluate the role of CK1α-mediated NSP2 phosphorylation on viroplasm formation, we used a recently published plasmid-based reverse genetics method to generate a recombinant rotavirus (rRV) with a phosphomimetic NSP2 mutation (rRV NSP2 S313D). The rRV NSP2 S313D virus is significantly delayed in viroplasm formation, virus replication, and interferes with wild type RV replication during co-infection. The rRV NSP2 S313A virus was not rescued. Taking advantage of the delay in viroplasm formation, the NSP2 S313D phosphomimetic mutant was used as a tool to observe very early events in viroplasm assembly. We show that (1) viroplasm assembly correlates with NSP5 hyperphosphorylation, and (2) that vNSP2 S313D co-localizes with RV-induced LDs without NSP5, suggesting that vNSP2 phospho-S313 is sufficient for interacting with LDs and may be the virus factor required for RV-induced LD formation. Further studies with the rRV NSP2 S313D virus are expected to reveal new aspects of viroplasm and LD initiation and assembly

Rotavirus Structural Proteins and dsRNA Are Required for the Human Primary Plasmacytoid Dendritic Cell IFNα Response

Rotaviruses are the leading cause of severe dehydrating diarrhea in children worldwide. Rotavirus-induced immune responses, especially the T and B cell responses, have been extensively characterized; however, little is known about innate immune mechanisms involved in the control of rotavirus infection. Although increased levels of systemic type I interferon (IFNα and β) correlate with accelerated resolution of rotavirus disease, multiple rotavirus strains, including rhesus rotavirus (RRV), have been demonstrated to antagonize type I IFN production in a variety of epithelial and fibroblast cell types through several mechanisms, including degradation of multiple interferon regulatory factors by a viral nonstructural protein. This report demonstrates that stimulation of highly purified primary human peripheral plasmacytoid dendritic cells (pDCs) with either live or inactivated RRV induces substantial IFNα production by a subset of pDCs in which RRV does not replicate. Characterization of pDC responses to viral stimulus by flow cytometry and Luminex revealed that RRV replicates in a small subset of human primary pDCs and, in this RRV-permissive small subset, IFNα production is diminished. pDC activation and maturation were observed independently of viral replication and were enhanced in cells in which virus replicates. Production of IFNα by pDCs following RRV exposure required viral dsRNA and surface proteins, but neither viral replication nor activation by trypsin cleavage of VP4. These results demonstrate that a minor subset of purified primary human peripheral pDCs are permissive to RRV infection, and that pDCs retain functionality following RRV stimulus. Additionally, this study demonstrates trypsin-independent infection of primary peripheral cells by rotavirus, which may allow for the establishment of extraintestinal viremia and antigenemia. Importantly, these data provide the first evidence of IFNα induction in primary human pDCs by a dsRNA virus, while simultaneously demonstrating impaired IFNα production in primary human cells in which RRV replicates. Rotavirus infection of primary human pDCs provides a powerful experimental system for the study of mechanisms underlying pDC-mediated innate immunity to viral infection and reveals a potentially novel dsRNA-dependent pathway of IFNα induction

Inhibition of Cellular Protein Secretion by Norwalk Virus Nonstructural Protein p22 Requires a Mimic of an Endoplasmic Reticulum Export Signal

Protein trafficking between the endoplasmic reticulum (ER) and Golgi apparatus is central to cellular homeostasis. ER export signals are utilized by a subset of proteins to rapidly exit the ER by direct uptake into COPII vesicles for transport to the Golgi. Norwalk virus nonstructural protein p22 contains a YXΦESDG motif that mimics a di-acidic ER export signal in both sequence and function. However, unlike normal ER export signals, the ER export signal mimic of p22 is necessary for apparent inhibition of normal COPII vesicle trafficking, which leads to Golgi disassembly and antagonism of Golgi-dependent cellular protein secretion. This is the first reported function for p22. Disassembly of the Golgi apparatus was also observed in cells replicating Norwalk virus, which may contribute to pathogenesis by interfering with cellular processes that are dependent on an intact secretory pathway. These results indicate that the ER export signal mimic is critical to the antagonistic function of p22, shown herein to be a novel antagonist of ER/Golgi trafficking. This unique and well-conserved human norovirus motif is therefore an appealing target for antiviral drug development

‘Inspired and assisted’, or ‘berated and destroyed’? Research leadership, management and performativity in troubled times

Research leadership in Australian universities takes place against a backdrop of policy reforms concerned with measurement and comparison of institutional research performance. In particular, the Excellence in Research in Australian initiative undertaken by the Australian Research Council sets out to evaluate research quality in Australian universities, using a combination of expert review process, and assessment of performance against &lsquo;quality indicators&rsquo;. Benchmarking exercises of this sort continue to shape institutional policy and practice, with inevitable effects on the ways in which research leadership, mentoring and practice are played out within university faculties and departments. In an exploratory study that interviewed 32 Australian academics in universities in four Australian states, we asked participants, occupying formal or informal research leadership roles, to comment on their perceptions of research leadership as envisioned and enacted in their particular workplaces. We found a pervasive concern amongst participants that coalesced around binaries characterized in metaphoric terms of &lsquo;carrots and whips&rsquo;. Research leadership was seen by many as managerial in nature, and as such, largely tethered to instrumentalist notions of productivity and performativity, while research cultures were seen as languishing under the demoralizing weight of reward and punishment systems. Here, we consider what is at stake for the future of the academic workforce under such conditions, arguing that new models of visionary research leadership are urgently needed in the &lsquo;troubled times&rsquo; of techno-bureaucratic university reforms.<br /

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy