I don't know about the difference between the two strains, but you could
save yourself a lot of worrying by simply testing the
interaction between the two proteins in vitro. In our
lab, we do this routinely after detecting an
interaction with the two-hybrid system. In addition,
most journals will require an vitro demonstration of
interaction before accepting your work for
WANGHO at UCBEH.SAN.UC.EDU wrote: : Hi there!
: I sent the following mail last week, titled with "Difference between 2
: strains", but there is no comment or suggestion back. If you read it before,
: please forget it. I re-post it with a new name for people in Two hybrid system
: paying attention to it. Thanks.
: Re: What is the difference between yeast strain ?
: Hi There!
: I am a newer in yeast but working on the yeast two hybrid system for almost
: three years. A lot of exciting data gave me a big picture about the cross
: talking among the proteins I am interested in. But one interaction bother me
: for a while. I guess this might be a potential problem or could be a
: commo-problem in the future using yeast two hybrid system.
: 1. I detected the interaction between Protein A and Protein B in Yeast strain,
: PCY2. The b-galactosidase activity induced by this interaction is beatiful.
: 2. Since some other strains have been developed (esp. using his and gal for
: double selection), I tried one. All positive are positive,and all negative are
: negative. Most interaction in my work showed positive. But A-B interaction
: showed negative (both in his and b-galactosidase).
: 3. I made a conclusion that there is no direct A-B interaction but a complex
: containing A and B is formed, and the A-B complex is medicated by other
: Above is the experiment and conclusion. It appears to be perfect to tell this
: story in my next publication. But, as I said, I am an user not a "yeastist".
: So I basically want ask myself and "yeastists" three questions.
: 1. Is the difference between strains enough to giving these difference? I
: understand that the difference between two animal cells might be trillion. Can
: some one tell me at what level the yeast strains show difference?
: 2. Am I so lucky to find this complex but an indirect interaction by using the
: second strain, which I pick randomly "one day"?
: 3. Obiviously, one like to know what is the third factor(s) mediating this
: interaction. Any suggestion to provide that there is such factor(s) before I
: screening the yeast library (beacuse the screen is not the first choice, at
: least for me)? Or is it easy to do substraction between this two strain? A
: particular question is what is the regular size for a yeast cDNA library?
: Any suggestion or comments are appreactiated. If this is a true problem in the
: using of two hybrid system, I wish this should be paid attention to. The
: false-positive might means more than what we thought.
: By the way, I can read "yeast at net.bio.net" through gopher. You can send mail
: to me or "yeast at net.bio.net".
: Thanks again!
: Hong F. Wang
: Department of Cell Biology, Neurobiology, and Anatomy
: University of CIncinnati College of Medicine
: 231 Bethesda Ave.
: Cincinnati, OH 45267-0521
: Phone: (513)558-6787
: Fax: (513)558-4454
: E-mail: wangho at ucbeh.san.uc.edu