Heat shock promoter sequences drive expression of the coding sequence and part of the 3' untranslated region of a mutant version of kuk in which the cysteine in the CaaX farnesylation motif has been replaced by a serine.
Expression of kukCS.hs in stage 9 embryos induces lobulation of the nuclear membrane, albeit weaker than when kukhs.PB is expressed.
Expression of kukCS.hs in a kuk mutant background (Df(3R)kuk15 in which GckIII function has been restored using GckIII+t5.3) does not induce nuclear membrane lobulation in stage 9 embryos.