A VERSATILE SET OF VECTORS FOR CONSTITUTIVE AND REGULATED GENE-EXPRESSION IN PICHIA-PASTORIS

The budding yeast Pichia pastor is is an attractive system for explori ng certain questions in cell biology, but experimental use of this org anism has been limited by a lack of convenient expression vectors. Her e we describe a set of compact vectors that should allow for the expre ssion of a wide range of endogenous or foreign genes in P. pastoris. A gene of interest is inserted into a modified pUC19 polylinker; target ed integration into the genome then results in stable and uniform expr ession of this gene. The utility of these vectors was illustrated by e xpressing the bacterial beta-glucuronidase (GUS) gene. Constitutive GU S expression was obtained with the strong GAP promoter or the moderate YPT1 promoter. The regulatable AOX1 promoter yielded very strong GUS expression in methanol-grown cells, negligible expression in glucose-g rown cells, and intermediate expression in mannitol-grown cells. GenBa nk Accession Numbers are: pIB1, AF027958; pIB2, AF027959; pIB3, AF0279 60; pIB4, AF027961. (C) 1998 John Wiley & Sons, Ltd.