发信人: Marble (小石头哥哥), 信区: Biology
标 题: Re: 土土地问
发信站: The unknown SPACE (Mon Apr 1 15:21:09 2002), 站内信件

expressing of interested protein in large quantity with the
help of appropriate vector in proper host. at first, biologists
developed plasmids as expression vector for "overexpression"
of certain gene in the bacteria host.for example, the mosar popule lacZ operon) and then
"overexpress" the exogenous protein in bacteria. however, since
the prokaryotes lack post-translational modifications of the
proteins, people developed other systems such as yeast, insect
cells as well as transformed mouse, monkey or human cells (most
of them are tumor-derived). the vectors need to be modified
as well since the host systems have been changed. overexpression
can help us get enough material for biochemical analysis, for
subcellular localization of the target protein, for study of
interaction with DNA and/or protein, for in vivo or in vitro
genetic manipulation (for example, many transgenic mice harbor
tissue-specific overexpression of certain gene) , etc.

【 在 clonist (pNL43Rev-) 的大作中提到: 】
: usually target genes are cloned into plasmids driven by modified
: promoters(not native promoter) such as CMV. those strong promoters
: will lead to overexpression of your gene compared to its native
: level. generally it does not hurt. but sometimes if dosage is
: important you have to be careful when interpreting your data.
: 【 在 abq (I Love JUNE) 的大作中提到: 】
: : overexpression 是怎么回事?
: : 一般怎么操作?


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