%0 Journal Article
%T Use of Bacterial Artificial Chromosomes in Baculovirus Research and Recombinant Protein Expression: Current Trends and Future Perspectives
%A Polly Roy
%A Rob Noad
%J ISRN Microbiology
%D 2012
%R 10.5402/2012/628797
%X The baculovirus expression system is one of the most successful and widely used eukaryotic protein expression methods. This short review will summarise the role of bacterial artificial chromosomes (BACS) as an enabling technology for the modification of the virus genome. For many years baculovirus genomes have been maintained in E. coli as bacterial artificial chromosomes, and foreign genes have been inserted using a transposition-based system. However, with recent advances in molecular biology techniques, particularly targeting reverse engineering of the baculovirus genome by recombineering, new frontiers in protein expression are being addressed. In particular, BACs have facilitated the propagation of disabled virus genomes that allow high throughput protein expression. Furthermore, improvement in the selection of recombinant viral genomes inserted into BACS has enabled the expression of multiprotein complexes by iterative recombineering of the baculovirus genome. 1. Baculovirus Protein Expression 1.1. Baculoviruses The Baculoviridae is a family of viruses with a circular dsDNA genome, ranging in size from 80£¿kb to 180£¿kb, that infect arthropods. Virus particles are rod-shaped, with a lipid envelope derived from the host cell. The family is divided into four genera, based on the comparison of a subset of core genes conserved between all baculoviruses [1, 2]. The viruses used for recombinant protein expression are Autographa californica multiple nucleopolyhedrosis virus(AcMNPV) and Bombyx mori nucleopolyhedrosis virus(BmNPV) and both are in the Alphabaculovirus genus. Both viruses are pathogens of the larval stages of lepidopteran species and have an infection cycle that involves ingestion and infection of the cells of the mid-gut, followed by systemic infection. In contrast to vertebrate herpesviruses, which have a similarly sized, circular DNA genome, and which are largely cryptic infections except in immunocompromised individuals, infection of caterpillars with AcMNPV and BmNPV results in a short duration, acute, systemic infection with liquefaction of the host (Figure 1). Once the host is liquefied, the virus remains in the environment encased in a protein matrix formed from the virally encoded polyhedrin protein until it is ingested by the next caterpillar and the alkali environment of the insect mid-gut triggers dissociation of the polyhedrin coat and release of the virus [3, 4]. Figure 1: Key stages in the infection cycle of AcMNPV. (A) Infection is initiated by the ingestion of a virus occlusion body (OB). This consists of multiple virus
%U http://www.hindawi.com/journals/isrn.microbiology/2012/628797/