Expression vectors for the synthesis of proteins and plasmid replicons and sequence cassettes for use in constructing such vectors

摘要

Expression vectors for the expression of proteins, particularly eukaryotic proteins are provided which are based on novel plasmid replicons. Sequence cassettes useful in constructing such vectors are also disclosed. The expression vectors according to the invention are useful for expressing selected proteins in insects and insect cells. Specifically, the plasmid replicons comprise double-stranded DNA having (a) one or more sequences allowing the replicon to be reproduced in a bacterial host, (b) first and second sequences which are adapted to permit an intervening sequence located between said first and second sequences to be introduced into an expression vector, and (c) an intervening sequence located between said first and second sequences, and are characterised in that the intervening sequence comprises first and second polypeptide expression sequences (PESs) wherein each PES includes (i) a transcriptional promotor (ii) a unique restriction site for introduction of a gene which is native or foreign to the expression vector and (iii) a transcriptional termination site.