Method and kit for expressing protein under regulation of the expression from repeated sequence formed by gene amplification and transformant

摘要

It is intended to provide a method of releasing the transcriptional regulation caused by a repeated sequence in a gene, a kit therefor and so on to thereby establish a system capable of producing a protein in a large amount. The above-described method can be achieved by any one or more of the following methods: (a) in the amplification of a gene encoding a target protein, co-amplifying a polynucleotide of 10kbp or more such as a λ-phage DNA or an insulator sequence; (b) selecting by culturing cells having undergone gene amplification in media containing a drug with a gradual increase in concentration; (c) elevating the promoter activity of inducing the expression of a gene encoding a target protein; (d) excising an amplified gene region from a chromosome with the use of Cre-LoxP System; (e) treating cells having undergone gene amplification with 5-aza-2'-deoxycytidine to thereby lower the methylation degree of DNA; and (f) selecting the mammalian cells having undergone gene amplification on double minute chromosomes.