A genetic analysis of glucoamylase activity in the diastatic yeast Saccharomyces cerevisiae NCYC 625

Abstract

The wild diastatic yeast Saccharomyces cerevisiae NCYC 625 has been shown to be homozygous for the glucoamylase-specifying gene STA2. spoII-1-mapping has positioned STA2 on chromosome II. Expression of STA2 is suppressed in some but not all diploids capable of sporulation, and is also inhibited by unlinked nuclear suppressor genes (SGL) found in some S. cerevisiae tester strains. EMS-induced glucoamylase-negative mutants often contain STA2-suppressor mutations. Depending on the allelic status of GEP1, a nuclear gene which also appears able to antagonise SGL-mediated suppression, STA2 expression can be blocked in petite mutants.

Mitochondrial Function in Cell Wall Glycoprotein Synthesis in Saccharomyces cerevisiae NCYC 625 (Wild Type) and [ rho 0 ] Mutants

“…Defects in excretion seemed to be due to changes in cell wall components or structure, as suggested by Tammi et al (35). The requirement of mitochondrial function for sugar use, flocculation, and enzyme secretion was described previously (8), particularly for the expression of STA, a gene encoding an excreted glucoamylase (1,4-␣-D-glucohydrolase) (27). Our flocculation and enzyme activity results are consistent with the hypothesis that defects in the respiratory chain lead to changes in cell wall structure.…”

Divergent Regulation of the Evolutionarily Closely Related Promoters of the Saccharomyces cerevisiae STA2 and MUC1 Genes

“…It was reported that the repressive effect of STA10 results from interaction between two unlinked genes, IST1 and IST2 (34), but this was not confirmed. The negative effects of several other genes (i.e., INH1 [58], SGL1 [36], and SNS1 and MSS1 [1]) on the transcription of the STA genes have also been reported, but the relationships between these negatively acting genes and the repressive effect of STA10 remain to be determined.…”

Localization of glucoamylase genes of Saccharomyces cerevisiae by pulsed field gel electrophoresis

“…One of these glucoamylases has recently been purified and characterized (Kleinman et al 1988b) and the relevant structural gene was shown to be STA2. Spoil-mapping (Klapholz & Esposito 1982) positioned STA2 on chromosome II (Patel et al 1982; Patel et al 1990) but this localization, contradicting an earlier report (Erratt & Stewart 1978) was not confirmed by mitotic or meiotic linkage analysis. This paper reports the separation of yeast chromosomes by pulsed field gel electrophoresis to produce electrophoretic karyotypes (Carle & Olsen 1985), which were blotted and hybridized with appropriate gene probes.…”

“…The STA genes of lab 1 are allelic to STA 2 (Patel et al 1990) and a STA 2 gene has been cloned by Meaden and colleagues (1985), and subsequently sequenced (Tubb 1984). The published sequences of STA 1 and STA 2 are closely similar, as there appear to be only two minor differences: the first is a silent substitution at the 259th base of STA 2, while the second is an insertion of a thymidine residue at the 2426th base position of STA 2, causing a frame shift in the last forty-six codons and extending the C-terminal end of STA 2 by thirty eight amino acid residues.…”