An Essential Role for the Proximal but Not the Distal Cytoplasmic Tail of Glycoprotein M in Murid Herpesvirus 4 Infection

Murid herpesvirus-4 (MuHV-4) provides a tractable model with which to define common, conserved features of gamma-herpesvirus biology. The multi-membrane spanning glycoprotein M (gM) is one of only 4 glycoproteins that are essential for MuHV-4 lytic replication. gM binds to gN and is thought to function mainly secondary envelopment and virion egress, for which several predicted trafficking motifs in its C-terminal cytoplasmic tail could be important. We tested the contribution of the gM cytoplasmic tail to MuHV-4 lytic replication by making recombinant viruses with varying C-terminal deletions. Removing an acidic cluster and a distal YXXΦ motif altered the capsid distribution somewhat in infected cells but had little effect on virus replication, either in vitro or in vivo. In contrast, removing a proximal YXXΦ motif as well completely prevented productive replication. gM was still expressed, but unlike its longer forms showed only limited colocalization with co-transfected gN, and in the context of whole virus appeared to support gN expression less well. We conclude that some elements of the gM cytoplasmic tail are dispensible for MuHV-4 replication, but the tail as a whole is not

Synthetic Biology: Mapping the Scientific Landscape

This article uses data from Thomson Reuters Web of Science to map and analyse the scientific landscape for synthetic biology. The article draws on recent advances in data visualisation and analytics with the aim of informing upcoming international policy debates on the governance of synthetic biology by the Subsidiary Body on Scientific, Technical and Technological Advice (SBSTTA) of the United Nations Convention on Biological Diversity. We use mapping techniques to identify how synthetic biology can best be understood and the range of institutions, researchers and funding agencies involved. Debates under the Convention are likely to focus on a possible moratorium on the field release of synthetic organisms, cells or genomes. Based on the empirical evidence we propose that guidance could be provided to funding agencies to respect the letter and spirit of the Convention on Biological Diversity in making research investments. Building on the recommendations of the United States Presidential Commission for the Study of Bioethical Issues we demonstrate that it is possible to promote independent and transparent monitoring of developments in synthetic biology using modern information tools. In particular, public and policy understanding and engagement with synthetic biology can be enhanced through the use of online interactive tools. As a step forward in this process we make existing data on the scientific literature on synthetic biology available in an online interactive workbook so that researchers, policy makers and civil society can explore the data and draw conclusions for themselves

The nucleotide recognized by the Escherichia coli A restriction and modification enzyme.

The nucleotide recognition sequence for the restriction-modification enzyme of Escherichia coli A (EcoA) has been determined to be GAG-7N-GTCA. This sequence is fairly similar, but distinctly different from the two other type I restriction enzyme recognition sites known for E. coli B and E. coli K12, respectively. N6-adenosine methylation has been observed at nucleotide positions 2 and 12 within that sequence after modification by EcoA. As a reference point for mapping the single EcoA site in lambda, the position of lambda point mutation Oam29 has been determined also

RNA polymerase I catalysed transcription of insert viral cDNA.

RNA polymerase I has been used for transcription of influenza hemagglutinin (HA) cDNA precisely linked in the anti-sense configuration to both mouse rDNA promoter and terminator segments. In transcription reactions based on Ehrlich ascites cell nuclear extracts, specific uniform RNA products are synthesized in high rates that are comparable to original rDNA template transcriptions. Primer extension reactions show the 5' ends of these RNA transcripts to be located exactly at position +1, corresponding to the 5' end of negative strand HA viral RNA. RNA 3' ends in a first series of constructs were found extended beyond the accepted location of pre-rRNA 3' ends, in using both hybrid cDNA and original rDNA templates. But upon deletion of six basepairs from the rDNA termination region RNA polymerase I transcription has been adapted to yield correctly terminated influenza viral RNA in vitro. This result has been confirmed in an in vivo experiment via synthesis of an anti-sense viral RNA molecule containing the chloramphenicol acetyltransferase (CAT) gene, which in turn is recognized at its terminal sequence by viral RNA dependent RNA polymerase for plus strand mRNA synthesis and expression of CAT activity