Portal de Periódicos da CAPES

Expression and regulation of the yeast MEL1 gene

1986; Oxford University Press; Volume: 34; Issue: 2 Linguagem: Inglês

10.1111/j.1574-6968.1986.tb01400.x

1574-6968

H Ruohola, Pirkko L. Liljeström, Tuula K. Torkkeli, Helena Kopu, Pirjo Lehtinen, Nisse Kalkkinen, Matti Korhola,

Fungal and yeast genetics research

The Saccharomyces cerevisiae var. uvarum MEL1 gene, conferring production of α-galactosidase, has been cloned to study its expression. Increasing amounts of α-galactosidase protein and activity closely followed the induction of functional MEL1 transcripts (1.65 kb). The initial appearance of the transcript occurred within 3–6 min and the corresponding α-galactosidase activity within 8–10 min of galactose addition. Therefore, regulation of α-galactosidase synthesis operates primarily at the level of MEL1 transcription. No transcription is detectable in glucose-grown cultures. α-Galactosidase activity is found in the periplasmic space and in the extracellular medium. Enzyme from either location exhibited a molecular size of 76 kDa, which was reduced to 53 kDa after deglycosylation with endoglycosidase H. The N-terminal sequence of purified α-galactosidase reveals cleavage of putative 18-amino-acid signal sequence for secretion.