In cultured cells the baculovirus P10 protein forms two independent intracellular structures that play separate roles in occlusion body maturation and their release by nuclear disintegration.

P10 is a small, abundant baculovirus protein that accumulates to high levels in the very late stages of the infection cycle. It is associated with a number of intracellular structures and implicated in diverse processes from occlusion body maturation to nuclear stability and lysis. However, studies have also shown that it is non-essential for virus replication, at least in cell culture.

Protein Production Using the Baculovirus Expression System.

Baculovirus expression systems are well established as an easy and reliable way to produce high quality recombinant proteins. Baculoviruses can also be used to transduce mammalian cells, termed 'BacMam', with considerable potential in biomedical applications. This chapter explains the process of making a recombinant baculovirus, encompassing production of a recombinant virus by homologous recombination in insect cells, followed by amplification and titration of the virus-all steps needed before commencing gene expression and protein production.

Overview of the Baculovirus Expression System.

This unit provides information on the replication cycle of insect baculovirus to provide an understanding of how this virus has been adapted for use as an expression vector for recombinant proteins in insect cells. We provide an overview of the virus structure and its unique bi-phasic replication cycle, which has been exploited in developing the virus as an expression vector. We also review the development of the baculovirus expression vector system (BEVS), from the mid-1980s to the present day in which the BEVS is now an established tool for the production of a range of recombinant proteins and multi-protein complexes including virus-like particles.

Superinfection exclusion in alphabaculovirus infections is concomitant with actin reorganization.

Unlabelled: Superinfection exclusion is the ability of an established virus to interfere with a second virus infection. This effect was studied in vitro during lepidopteran-specific nucleopolyhedrovirus (genus Alphabaculovirus, family Baculoviridae) infection. Homologous interference was detected in Sf9 cells sequentially infected with two genotypes of Autographa californica multiple nucleopolyhedrovirus (AcMNPV), each one expressing a different fluorescent protein.

The effect of genetic background and dose on non-targeted effects of radiation.

Purpose: This work investigates the hypothesis that genetic background plays a significant role in the signalling mechanisms underlying induction and perpetuation of genomic instability following radiation exposure.

Materials And Methods: Bone marrow from two strains of mice (CBA and C57) were exposed to a range of X-ray doses (0, 0.01, 0.

No influence of serotonin levels in foetal bovine sera on radiation-induced bystander effects and genomic instability.

Purpose: The aim of this study was to contribute to an inter-laboratory investigation within the Non-Targeted Effects of Ionising Radiation Integrated project (NOTE) (2006-2010) to investigate the role of serum serotonin concentration on radiation-induced bystander effects using our successful experimental design. Two sera of high and low serotonin levels were tested alongside standard serum used in our laboratory.

Materials And Methods: Primary Human Fibroblast 19 (HF19) cells were sham/irradiated with 0.

Possible role of exosomes containing RNA in mediating nontargeted effect of ionizing radiation.

Communication between irradiated and un-irradiated (bystander) cells can cause damage in cells that are not directly targeted by ionizing radiation, a process known as the bystander effect. Bystander effects can also lead to chromosomal/genomic instability within the progeny of bystander cells, similar to the progeny of directly irradiated cells. The factors that mediate this cellular communication can be transferred between cells via gap junctions or released into the extracellular media following irradiation, but their nature has not been fully characterized.

Host cell processes to accomplish mechanical and non-circulative virus transmission.

Mechanical vector-less transmission of viruses, as well as vector-mediated non-circulative virus transmission, where the virus attaches only to the exterior of the vector during the passage to a new host, are apparently simple processes: the viruses are carried along with the wind, the food or by the vector to a new host. We discuss here, using the examples of the non-circulatively transmitted Cauliflower mosaic virus that binds to its aphid vector's exterior mouthparts, and that of the mechanically (during feeding activity) transmitted Autographa californica multicapsid nucleopolyhedrovirus, that transmission of these viruses is not so simple as previously thought. Rather, these viruses prepare their transmission carefully and long before the actual acquisition event.

Expression and plasma membrane localization of the mammalian B-cell receptor complex in transgenic Nicotiana tabacum.

The B-cell antigen receptor (BCR), displayed on the plasma membrane of mature B cells of the mammalian immune system, is a multimeric complex consisting of a membrane-bound immunoglobulin (mIg) noncovalently associated with the Igα/Igβ heterodimer. In this study, we engineered transgenic tobacco plants expressing all four chains of the BCR. ELISA, Western blotting and confocal microscopy demonstrated that the BCR was correctly assembled in plants, predominantly in the plasma membrane, and that the noncovalent link was detergent sensitive.

Fluorescent protein fusions to a human immunodeficiency virus monoclonal antibody reveal its intracellular transport through the plant endomembrane system.

In order to further understand the production and intracellular trafficking of pharmaceutical proteins in plants, the light and heavy chains (LC and HC) of the human immunodeficiency virus neutralizing monoclonal antibody 2G12 were fused to fluorescent proteins [Venus and monomeric red fluorescent protein (mRFP)] to enable the visualization of their passage through the plant cell. Co-expression of LC and HC with various markers of the endomembrane system demonstrated that LC fusions were found in mobile punctate structures, which are likely to be pre-vacuolar compartments (PVCs) as a proportion of the LC fusions were found to be located in the vacuole. In addition, apoplast labelling was also observed with a 2G12LC-RFP fusion.

Retention and mobility of the mammalian lamin B receptor in the plant nuclear envelope.

Background Information: In a previous study, we showed that GFP (green fluorescent protein) fused to the N-terminal 238 amino acids of the mammalian LBR (lamin B receptor) localized to the NE (nuclear envelope) when expressed in the plant Nicotiana tabacum. The protein was located in the NE during interphase and migrated with nuclear membranes during cell division. Targeting and retention of inner NE proteins requires several mechanisms: signals that direct movement through the nuclear pore complex, presence of a transmembrane domain or domains and retention by interaction with nuclear or nuclear-membrane constituents.

The plant nuclear envelope: new prospects for a poorly understood structure.

The nuclear envelope (NE) is one of the least characterized cellular structures in plant cells. In particular, knowledge of its dynamic behaviour during the cell cycle and of its protein composition is limited. This review summarizes current views on the plant NE and highlights fundamental differences with other organisms.

The first 238 amino acids of the human lamin B receptor are targeted to the nuclear envelope in plants.

In plants, the nuclear envelope (NE) is one of the least characterized cellular structures. In particular, little is known about its dynamics during the cell cycle. This is due to the absence of specific markers for in vivo studies.