Protein expression system

Abstract

Disclosed is a DNA polynucleotide comprising a nucleic acid sequence having promoter activity in aS2 cell, where said nucleic acid sequence is selected from (i) a nucleotide sequence of SEQ ID NO: 1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO: 5, SEQ ID NO:6, SEQ ID NO:33, SEQ ID NO:36, SEQ ID NO: 37, or SEQ ID NO: 68 with or without flanking restriction site sequences at either terminus; (ii) a functional nucleotide sequence with a sequence identity of at least 80% to any one sequence of (i); (iii) a nucleotide which is a functional fragment of at least 6 contiguous nucleotides of any one sequence of (i) or (ii); (iv) a functional nucleotide sequence with a sequence identity of at least 80% to said functional fragment of (iii); (v) a first chimeric nucleotide sequence comprising two or more sequences of any one sequence of (i), (ii), (iii) and (iv), and (vi) a second chimeric nucleotide sequence, comprising at least 6 nucleotides and including consecutive nucleotide stretches from at least 2 nucleotide sequences of (iii) and/or (iv), where each of said consecutive stretches alone does not have promoter activity in aS2 cell. Also disclosed are vectors and cells comprising the polynucleotide and a method for producing a polypeptide of interest by use of the polynucleotide.