Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.26 (invertase)
 4,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The coding sequence of the SUC2 locus was placed under the control of the constitutive ADH1 promoter and transcription terminator in a centromere-based yeast plasmid vector from which invertase is expressed in a Suc- strain of Saccharomyces cerevisiae. Mutants in the signal peptide sequence were produced by replacing this region of the gene with synthetic oligonucleotide cassettes containing mixtures of nucleotides at several positions. The mutants could be divided into three classes on the basis of the ability to secrete invertase. Class I mutants produced secreted invertase but in reduced amount. The class II mutant, 4-55B, also exhibited reduced a level of invertase, but a significant fraction of the enzyme was intracellular. Class III mutants were partially defective in translocation from the cytoplasm to the endoplasmic reticulum and produced enzymatically active, unglycosylated preinvertase in the cytoplasm. Class III mutant preinvertases were also defective in translocation across canine pancreas microsomes. These results suggested that the reduced level of invertase resulted from proteolytic degradation of inefficiently transported intermediates. Comparison of the sequences of the mutant signal peptides indicated that amino acids at the extreme amino terminus and adjacent to the cleavage site play a crucial role in the secretory process when combined with a mutation within the hydrophobic core.
 ...
PMID:Cassette mutagenic analysis of the yeast invertase signal peptide: effects on protein translocation. 267 71

Increased production of secreted proteins in Saccharomyces cerevisiae was achieved by overexpressing the yeast syntaxins. Sso1 or Sso2 protein, the t-SNAREs functioning at the targeting/fusion of the Golgi-derived secretory vesicles to the plasma membrane. Up to four- or six-fold yields of a heterologous secreted protein, Bacillus alpha-amylase, or an endogenous secreted protein, invertase, were obtained respectively when expressing either one of the SSO genes, SSO1 or SSO2, from the ADH1 promoter on a multicopy plasmid. Direct correlation between the Sso protein level and the amount of secreted alpha-amylase was demonstrated by modulating the expression level of the SSO2 gene. Quantitation of the alpha-amylase activity in the culture medium, periplasmic space and cytoplasm suggests that secretion into the periplasmic space is the primary stage at which the SSO genes exert the secretion-enhancing function. Pulse-chase data also support enhanced secretion efficiently obtained by SSO overexpression. Our data suggest that the Sso proteins may be rate-limiting components of the protein secretion machinery at the exocytosis step in yeast.
 ...
PMID:Enhancement of protein secretion in Saccharomyces cerevisiae by overproduction of Sso protein, a late-acting component of the secretory machinery. 913 37

The secretion of proteins depends on the signal peptide located to the N-terminal of the protein precursor. We established a genetic system in yeast to screen cDNA library for the signal peptide encoding sequences. To do it, we mutated genomic suc2 gene (encoding yeast invertase) of EGY48 by one-step gene disruption method, and got yeast cell lines without invertase expression (EGY48-delta suc). To get vector for library screening, we inserted suc2 gene encoding mature peptide of invertase downstream to yeast promoter P-ADH1, and multiple cloning sites for insertion of library is between suc2 and P-ADH1. EGY48-delta suc transformed with the vector can grow on the medium with glucose as carbon source, but not on the medium with raffinose. Signal peptide of suc2 and alpha chain of human interleukin-2 was fused in frame to suc2 gene, then the two resulting vectors were transformed into EGY48-delta suc, all the transformants can grow in the medium with either raffinose or glucose as carbon source. Hence, the system established here can discern cDNA encoding signal peptide from the one not encoding signal peptide.
 ...
PMID:[Establishment of suc2 signal sequence trap system]. 1132 81

The promoters of high-affinity hexose transporter, HXT6 and HXT7, are sufficient for complementary expression of invertase to restore the growth of Saccharomyces cerevisiae in raffinose medium. The HXT7 promoter produced higher invertase activity at 139- and 30-fold of the basal activity in strains GN 3C.2 and W303-1, respectively. In addition, the HXT7 promoter expressed 3- to 9-fold more of enhanced green fluorescent protein than that of the constitutive ADH1 in three different S. cerevisiae strains, even during short-term incubation in glucose medium. Therefore, HXT7 promoter could be used for heterologous protein expression in S. cerevisiae.
 ...
PMID:Cell growth restoration and high level protein expression by the promoter of hexose transporter, HXT7, from Saccharomyces cerevisiae. 1752 Jan 77