title: Impaired cutinase secretion in Saccharomyces cerevisiae induces irregular endoplasmic reticulum (ER) membrane proliferation, oxidative stress, and ER-associated degradation.
abstract: Impaired secretion of the hydrophobic CY028 cutinase invokes an unfolded protein response (UPR) in Saccharomyces cerevisiae cells. Here we show that the UPR in CY028-expressing S. cerevisiae cells is manifested as an aberrant morphology of the endoplasmic reticulum (ER) and as extensive membrane proliferation compared to the ER morphology and membrane proliferation of wild-type CY000-producing S. cerevisiae cells. In addition, we observed oxidative stress, which resulted in a 21-fold increase in carbonylated proteins in the CY028-producing S. cerevisiae cells. Moreover, CY028-producing S. cerevisiae cells use proteasomal degradation to reduce the amount of accumulated CY028 cutinase, thereby attenuating the stress invoked by CY028 cutinase expression. This proteasomal degradation occurs within minutes and is characteristic of ER-associated degradation (ERAD). Our results clearly show that impaired secretion of the heterologous, hydrophobic CY028 cutinase in S. cerevisiae cells leads to protein aggregation in the ER, aberrant ER morphology and proliferation, and oxidative stress, as well as a UPR and ERAD.
authors.affiliation: DSM-Gist, 2600 MA Delft, The Netherlands.
authors.forename: C M J
authors.initials: CM
authors.lastname: Sagt
authors.forename: W H
authors.initials: WH
authors.lastname: Müller
authors.forename: L
authors.initials: L
authors.lastname: van der Heide
authors.forename: J
authors.initials: J
authors.lastname: Boonstra
authors.forename: A J
authors.initials: AJ
authors.lastname: Verkleij
authors.forename: C T
authors.initials: CT
authors.lastname: Verrips
mesh_terms: D002265:Carboxylic Ester Hydrolases / Q000096:biosynthesis / Q000378:metabolism*; D003546:Cysteine Endopeptidases / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000502:physiology*; D057927:Hydrophobic and Hydrophilic Interactions; D009097:Multienzyme Complexes / Q000378:metabolism; D018384:Oxidative Stress / Q000502:physiology*; D046988:Proteasome Endopeptidase Complex; D011489:Protein Denaturation; D017510:Protein Folding; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000378:metabolism
chemical_list: D009097:Multienzyme Complexes; D002265:Carboxylic Ester Hydrolases; C019952:cutinase; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex