GAL4 and bZIP proteins in 2-hybrid

[Ian Donaldson]

Dear yeast netters

A paper published last year (Sollerbrant et. al NAR 23(4):588) indicated
that the GAL4 DNA-binding domain can interact with the bZIP domain of
c-JUN.  Given this data, one might expect that a set of common false
positives from any two-hybrid screen would include the yeast bZIP proteins
(GCN4, YAP1/SNQ3/PAR1/PDR4 and CAD1).  (These types of false positives
should be weeded out of a screen when tested against other non-relevant
baits, but this may not always be true.)  Also, this observation might
explain why the GAL4 DNA-binding domain has a low level of activating
ability by itself in the two hybrid system; this activity is usually
destroyed by fusing something to the DNA-binding domain.

Has anyone pulled any of these bZIP proteins out of a 2-hybrid screen?  Are
there other false positives that are reproducibly pulled out of the screen?

I have already done a search of the yeast.net archives and came up with
nothing of relevance.

Send me your junk (reproducible) and I will post a summary.

Thanks for any replies
Ian Donaldson