EXPRESSION VECTOR WITH DUAL CONTROL OF REPLICATION AND TRANSCRIPTION

摘要

The present invention provides an expression vector adapted for inducible amplification and inducible transcription of a heterologous polynucleotide operably linked to a transcriptional promoter provided in the vector. The invention further provides a method for using the vector to produce large quantities of a heterologous polypeptide encoded by the heterologous polynucleotide. The pBAC of the present invention is derived from a BAC cloning vector by modifying the BAC cloning vector to include a conditional ori for amplifying the pBAC and an inducible promoter for regulating the transcription of an inserted gene. Both the conditional ori and the inducible promoter can be activated jointly or separately by suitable signals in a host cell. Once a polynucleotide of interest is inserted into the pBAC and the pBAC is introduced into a host cell, the level of the product encoded by the polynucleotide can be controlled by regulating the copy number of the expression vector or the activity of the promoter under which transcription of the inserted polynucleotide is controlled, or both.