In article <1995Apr5.141110.4497 at alw.nih.gov>, rchun at helix.nih.gov (Rene
Franz Chun) wrote:
> We are trying to look at a transcriptional regulatory protein
> and we want to express it in SL2 cells. I know they normally
> grow at 22 degrees. However, I've heard that some people express
> their gene of interest using a heat shock promoter and will
> grow the cells at 37 for 20 minutes or so.
>> What might be some of the pros and cons between expressing
> at 22 degrees vs. 37 degrees?
>> novice with drosophila cells,
Addendum to previous post-- After reading your message thoroughly.
If you want high levels of gene expression, many groups accomplish this
through construction of a chimaeric gene containing your cDNA of interest
fused to the hsp70 (or hsp83) promoter. hsp 70 has very low constitutive
activity in the absence of heat shock (37 degrees), but one can achieve an
increase in gene expression of several orders of magnitude after heat
shock (1 hr or so at 37 degrees).
Pros__inducible high level expression, convenient, many vectors available
from various labs, generally more gene product produced than when using
the endogenous promoter.
Cons-- may overwhelm post-transcriptional or post-translational
modifications, if they exist, but this is usually not observed.