title: Lectin OS-9 delivers mutant neuroserpin to endoplasmic reticulum associated degradation in familial encephalopathy with neuroserpin inclusion bodies.
abstract: A feature of neurodegenerative diseases is the intraneuronal accumulation of misfolded proteins. In familial encephalopathy with neuroserpin inclusion bodies (FENIB), mutations in neuroserpin lead to accumulation of neuroserpin polymers within the endoplasmic reticulum (ER) of neurons. Cell culture based studies have shown that ER-associated degradation (ERAD) is involved in clearance of mutant neuroserpin. Here, we investigate how mutant neuroserpin is delivered to ERAD using cell culture and a murine model of FENIB. We show that the ER-lectin OS-9 but not XTP3-B is involved in ERAD of mutant neuroserpin. OS-9 binds mutant neuroserpin and the removal of glycosylation sites leads to increased neuroserpin protein load whereas overexpression of OS-9 decreases mutant neuroserpin. In FENIB mice, OS-9 but not XTP3-B is differently expressed and impairment of ERAD by partial inhibition of the ubiquitin proteasome system leads to increased neuroserpin protein load. These findings show that OS-9 delivers mutant neuroserpin to ERAD by recognition of glycan side chains and provide the first in vivo proof of involvement of ERAD in degradation of mutant neuroserpin.
authors.affiliation: Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Angela
authors.initials: A
authors.lastname: Schipanski
authors.affiliation: Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Oberhauser
authors.affiliation: Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Melanie
authors.initials: M
authors.lastname: Neumann
authors.affiliation: Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Sascha
authors.initials: S
authors.lastname: Lange
authors.affiliation: Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Beata
authors.initials: B
authors.lastname: Szalay
authors.affiliation: Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Krasemann
authors.affiliation: Department of Neuroscience, Maastricht University, Maastricht, the Netherlands.
authors.forename: Fred W
authors.initials: FW
authors.lastname: van Leeuwen
authors.affiliation: Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Galliciotti
authors.affiliation: Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. Electronic address: m.glatzel@uke.de.
authors.forename: Markus
authors.initials: M
authors.lastname: Glatzel
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004195:Disease Models, Animal; D004721:Endoplasmic Reticulum; D060746:Endoplasmic Reticulum-Associated Degradation / Q000235:genetics*; D004831:Epilepsies, Myoclonic / Q000235:genetics* / Q000378:metabolism; D006031:Glycosylation; D020271:Heredodegenerative Disorders, Nervous System / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D037102:Lectins / Q000378:metabolism*; D008822:Mice, Transgenic; D009154:Mutation; D009363:Neoplasm Proteins / Q000378:metabolism*; D009479:Neuropeptides / Q000235:genetics* / Q000378:metabolism*; D011134:Polysaccharides / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex; D011485:Protein Binding; D021381:Protein Transport; D059748:Proteolysis; D015843:Serpins / Q000235:genetics* / Q000378:metabolism*; D025801:Ubiquitin; D000097522:Neuroserpin
chemical_list: D037102:Lectins; D009363:Neoplasm Proteins; D009479:Neuropeptides; D011134:Polysaccharides; D046988:Proteasome Endopeptidase Complex; D015843:Serpins; D025801:Ubiquitin; D000097522:Neuroserpin; C098898:OS9 protein, human
keywords: Dementia; ER-associated degradation; Neuropathology; Neuroserpin; Proteasome; Proteostasis