Enlargement of the endoplasmic reticulum membrane in Saccharomyces cerevisiae is not necessarily linked to the unfolded protein response via Ire1p.
Conditions that stress the endoplasmic reticulum (ER) in Saccharomyces cerevisiae can elicit a combination of an unfolded protein response (UPR) and an inositol response (IR). This results in increased synthesis of ER protein-folding factors and of enzymes participating in phospholipid biosynthesis. It was suggested that in cells grown on glucose or galactose medium, the UPR and the IR are linked and controlled by the ER stress sensor Ire1p. However, our studies suggest that during growth on oleate the IR is controlled both by an Ire1p-dependent pathway and by an Ire1p-independent pathway.
Stroobants
A K
AK
Department of Biochemistry, Academic Medical Centre, Amsterdam, The Netherlands.
Hettema
E H
EH
van den Berg
M
M
Tabak
H F
HF
D000220:Adaptation, Biological; D004721:Endoplasmic Reticulum / Q000502:physiology* / Q000648:ultrastructure; D005656:Fungal Proteins / Q000378:metabolism*; D005690:Galactose / Q000378:metabolism; D017353:Gene Deletion; D008562:Membrane Glycoproteins / Q000378:metabolism*; D008565:Membrane Proteins / Q000096:biosynthesis; D008830:Microbodies / Q000502:physiology*; D007296:Myo-Inositol-1-Phosphate Synthase / Q000096:biosynthesis; D019301:Oleic Acid / Q000378:metabolism; D010750:Phosphoproteins / Q000096:biosynthesis; D017510:Protein Folding; D017346:Protein Serine-Threonine Kinases; D012441:Saccharomyces cerevisiae / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins
D005656:Fungal Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; C110177:PEX15 protein, S cerevisiae; D010750:Phosphoproteins; D029701:Saccharomyces cerevisiae Proteins; D019301:Oleic Acid; C082863:IRE1 protein, S cerevisiae; D017346:Protein Serine-Threonine Kinases; D007296:Myo-Inositol-1-Phosphate Synthase; D005690:Galactose