Presence of STA gene sequences in brewer's yeast genome

Abstract

STA genes are responsible for producing extracellular glucoamylase enzymes in Saccharomyces cerevisiae var. diastaticus. These genes exist in three forms, which are located on three different chromosomes. The nucleotide sequences of the STA genes are highly homologous. A sporulation-specific glucoamylase gene called SGA1 exists in every Saccharomyces cerevisiae strain, this also having a partly homologous DNA sequence with the STA genes. In this study S. cerevisiae var. diastaticus and brewer's yeast strains were characterized by pulsed-field gel electrophoresis. In many cases chromosome length polymorphism (CLP) was found. The chromosomes were hybridized with a DNA probe which was homologous with STA genes and the SGA1 gene. Presence of the SGA1 gene was detected in each strain used. Four brewing yeasts were found to have homologous sequences with the STA3 gene on chromosome XIV despite the fact that these strains were not able to produce extracellular glucoamylase enzyme.

Assistance for Folding of Disease-Causing Plasma Membrane Proteins

“…When the ER protein in the lumen is translocated across the membrane, the protein is shifted laterally for anchoring within the phospholipid bilayer, allowing the protein to be integrated or assembled with other proteins into the ER membrane [54,55]. During translocation, enzymes (e.g., signal peptidases and oligosaccharyltransferase) can associate with the protein to cleave the signal peptide or N-glycosylate the translocating nascent chain [56,57].…”

“…After sensing ER stress, oligomerization of the luminal domain (N-terminal) of PERK facilitates autophosphorylation. After PERK is processed, it phosphorylates the α subunit of eukaryotic initiation factor 2 (eIF2α), which induces a transient attenuation of protein translation along with the activation of stress-responsive transcription factors to stimulate the expression of chaperones, oxidative response genes and autophagy/apoptosis genes, among other UPR-related proteins [53][54][55]91,92].…”