Identification of upstream activator sequences that regulate induction of the beta-galactosidase gene in Kluyveromyces lactis.

摘要: Transcription of the Kluyveromyces lactis beta-galactosidase gene, LAC4, is inducible by galactose and lactose. We examined effects deletion mutations within LAC4 promoter on expression activity. The results these experiments indicate that at least two upstream activator sequences (UAS) mediate maximum induction galactose. These UAS sequence elements are homologous to regulate melibiose-galactose regulon Saccharomyces cerevisiae. also show a synthetic copy one K. restores inducibility deleted, noninducible promoter. Since uninduced or basal level was increased in several strains carrying UAS, we contribution LAC9 positive regulatory protein this effect. thought bind activate transcription (L.V. Wray, M.M. Witte, R.C. Dickson, M.I. Riley, Mol. Cell. Biol. 7:1111-1121, 1987). Our demonstrate plays role setting gene expression, but other factors participate. For example, lac9 background mutant with copies 17-base-pair yields sevenfold higher than same strain UAS. data strongly influenced base