title: High resolution microscopy reveals an unusual architecture of the Plasmodium berghei endoplasmic reticulum.
abstract: To fuel the tremendously fast replication of Plasmodium liver stage parasites, the endoplasmic reticulum (ER) must play a critical role as a major site of protein and lipid biosynthesis. In this study, we analysed the parasite's ER morphology and function. Previous studies exploring the parasite ER have mainly focused on the blood stage. Visualizing the Plasmodium berghei ER during liver stage development, we found that the ER forms an interconnected network throughout the parasite with perinuclear and peripheral localizations. Surprisingly, we observed that the ER additionally generates huge accumulations. Using stimulated emission depletion microscopy and serial block-face scanning electron microscopy, we defined ER accumulations as intricate dense networks of ER tubules. We provide evidence that these accumulations are functional subdivisions of the parasite ER, presumably generated in response to elevated demands of the parasite, potentially consistent with ER stress. Compared to higher eukaryotes, Plasmodium parasites have a fundamentally reduced unfolded protein response machinery for reacting to ER stress. Accordingly, parasite development is greatly impaired when ER stress is applied. As parasites appear to be more sensitive to ER stress than are host cells, induction of ER stress could potentially be used for interference with parasite development.
authors: Institute of Cell Biology, University of Bern, Baltzerstr. 4, 3012 Bern, Switzerland.|Graduate School for Cellular and Biomedical Sciences, University of Bern, Baltzerstrasse 2, 3012, Bern, Switzerland.
authors: Gesine
authors: G
authors: Kaiser
authors: Institute of Cell Biology, University of Bern, Baltzerstr. 4, 3012 Bern, Switzerland.|Wellcome Trust Center for Molecular Parasitology, G12 8TA, Glasgow, UK.
authors: Mariana
authors: M
authors: De Niz
authors: Institute of Anatomy, University of Bern, Baltzerstrasse 2, 3012, Bern, Switzerland.
authors: Benoît
authors: B
authors: Zuber
authors: Institute of Cell Biology, University of Bern, Baltzerstr. 4, 3012 Bern, Switzerland.
authors: Paul-Christian
authors: PC
authors: Burda
authors: Institute of Biochemistry, ETH Zürich, Otto-Stern-Weg 3, 8093, Zürich, Switzerland.
authors: Benoît
authors: B
authors: Kornmann
authors: Institute of Cell Biology, University of Bern, Baltzerstr. 4, 3012 Bern, Switzerland.
authors: Volker T
authors: VT
authors: Heussler
authors: Institute of Cell Biology, University of Bern, Baltzerstr. 4, 3012 Bern, Switzerland.
authors: Rebecca R
authors: RR
authors: Stanway
mesh_terms: D000818:Animals; D004721:Endoplasmic Reticulum / Q000378:metabolism / Q000648:ultrastructure*; D059865:Endoplasmic Reticulum Stress; D008099:Liver / Q000469:parasitology; D008288:Malaria / Q000469:parasitology; D008853:Microscopy / Q000379:methods; D008855:Microscopy, Electron, Scanning; D010962:Plasmodium berghei / Q000378:metabolism / Q000648:ultrastructure*; D015800:Protozoan Proteins / Q000378:metabolism; D056811:Unfolded Protein Response
chemical_list: D015800:Protozoan Proteins