title: Transcription and expression of zein sequences in yeast under natural plant or yeast promoters.
abstract: Maize genomic fragments containing the regulatory and coding regions of a zein gene for a low size class 23-kd protein have been inserted in an interspecific Escherichia coli-Saccharomyces cerevisiae expression vector in different constructions. The presence of the inducible GAL1-10 upstream activation site (UAS) allows us to regulate differentially by carbon sources the transcription of the zein gene both under the plant promoter and under the yeast CYC-1 promoter. We found that the zein promoter region is properly recognized at the correct transcription start, while different termination points occur during transcription. The yeast UAS was also shown to function as a typical eukaryotic enhancer regardless of its distance or orientation with respect to the plant promoter. Yeast cells transformed by a plasmid containing a zein sequence fused to a short piece of the CYC-1 gene produced a fused polypeptide, of expected mol. wt, in variable amount from 0.2 to 5% depending on the growth phase conditions.
authors.affiliation: Istituto Biosintesi Vegetali, C.N.R., Via Bassini, 15, 20133 Milano, Italy.
authors.forename: I
authors.initials: I
authors.lastname: Coraggio
authors.forename: C
authors.initials: C
authors.lastname: Compagno
authors.forename: E
authors.initials: E
authors.lastname: Martegani
authors.forename: B M
authors.initials: BM
authors.lastname: Ranzi
authors.forename: E
authors.initials: E
authors.lastname: Sala
authors.forename: L
authors.initials: L
authors.lastname: Alberghina
authors.forename: A
authors.initials: A
authors.lastname: Viotti