Interactome screening of C9orf72 dipeptide repeats reveals VCP sequestration and functional impairment by polyGA

Janja Bozič; Helena Motaln; Anja Pucer Janez; Lara Markič; Priyanka Tripathi; Alfred Yamoah; Eleonora Aronica; Youn Bok Lee; Raphael Heilig; Roman Fischer; Andrew J. Thompson; Anand Goswami; Boris Rogelj

doi:10.1093/brain/awab300

Interactome screening of C9orf72 dipeptide repeats reveals VCP sequestration and functional impairment by polyGA

Janja Bozič, Helena Motaln, Anja Pucer Janez, Lara Markič, Priyanka Tripathi, Alfred Yamoah, Eleonora Aronica, Youn Bok Lee, Raphael Heilig, Roman Fischer, Andrew J. Thompson, Anand Goswami, Boris Rogelj^*

^*Corresponding author for this work

Basic and Clinical Neuroscience

Research output: Contribution to journal › Article › peer-review

17 Citations (Scopus)

Abstract

Repeat expansions in the C9orf72 gene are a common cause of amyotrophic lateral sclerosis and frontotemporal lobar degeneration, two devastating neurodegenerative disorders. One of the proposed mechanisms of GGGGCC repeat expansion is their translation into non-canonical dipeptide repeats, which can then accumulate as aggregates and contribute to these pathologies. There are five different dipeptide repeat proteins (polyGA, polyGR, polyPR, polyPA and polyGP), some of which are known to be neurotoxic. In the present study, we used BioID2 proximity labelling to identify the interactomes of all five dipeptide repeat proteins consisting of 125 repeats each. We identified 113 interacting partners for polyGR, 90 for polyGA, 106 for polyPR, 25 for polyPA and 27 for polyGP. Gene Ontology enrichment analysis of the proteomic data revealed that these target interaction partners are involved in a variety of functions, including protein translation, signal transduction pathways, protein catabolic processes, amide metabolic processes and RNA-binding. Using autopsy brain tissue from patients with C9orf72 expansion complemented with cell culture analysis, we evaluated the interactions between polyGA and valosin containing protein (VCP). Functional analysis of this interaction revealed sequestration of VCP with polyGA aggregates, altering levels of soluble valosin-containing protein. VCP also functions in autophagy processes, and consistent with this, we observed altered autophagy in cells expressing polyGA. We also observed altered co-localization of polyGA aggregates and p62 in cells depleted of VCP. All together, these data suggest that sequestration of VCP with polyGA aggregates contributes to the loss of VCP function, and consequently to alterations in autophagy processes in C9orf72 expansion disorders.

Original language	English
Pages (from-to)	684-699
Number of pages	16
Journal	Brain
Volume	145
Issue number	2
DOIs	https://doi.org/10.1093/brain/awab300
Publication status	Published - 1 Feb 2022

Keywords

ALS
autophagy
C9orf72
VCP

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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10.1093/brain/awab300

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@article{fbc34525ccab4997b6f9e138d5b65713,

title = "Interactome screening of C9orf72 dipeptide repeats reveals VCP sequestration and functional impairment by polyGA",

abstract = "Repeat expansions in the C9orf72 gene are a common cause of amyotrophic lateral sclerosis and frontotemporal lobar degeneration, two devastating neurodegenerative disorders. One of the proposed mechanisms of GGGGCC repeat expansion is their translation into non-canonical dipeptide repeats, which can then accumulate as aggregates and contribute to these pathologies. There are five different dipeptide repeat proteins (polyGA, polyGR, polyPR, polyPA and polyGP), some of which are known to be neurotoxic. In the present study, we used BioID2 proximity labelling to identify the interactomes of all five dipeptide repeat proteins consisting of 125 repeats each. We identified 113 interacting partners for polyGR, 90 for polyGA, 106 for polyPR, 25 for polyPA and 27 for polyGP. Gene Ontology enrichment analysis of the proteomic data revealed that these target interaction partners are involved in a variety of functions, including protein translation, signal transduction pathways, protein catabolic processes, amide metabolic processes and RNA-binding. Using autopsy brain tissue from patients with C9orf72 expansion complemented with cell culture analysis, we evaluated the interactions between polyGA and valosin containing protein (VCP). Functional analysis of this interaction revealed sequestration of VCP with polyGA aggregates, altering levels of soluble valosin-containing protein. VCP also functions in autophagy processes, and consistent with this, we observed altered autophagy in cells expressing polyGA. We also observed altered co-localization of polyGA aggregates and p62 in cells depleted of VCP. All together, these data suggest that sequestration of VCP with polyGA aggregates contributes to the loss of VCP function, and consequently to alterations in autophagy processes in C9orf72 expansion disorders. ",

keywords = "ALS, autophagy, C9orf72, VCP",

author = "Janja Bozi{\v c} and Helena Motaln and Janez, {Anja Pucer} and Lara Marki{\v c} and Priyanka Tripathi and Alfred Yamoah and Eleonora Aronica and Lee, {Youn Bok} and Raphael Heilig and Roman Fischer and Thompson, {Andrew J.} and Anand Goswami and Boris Rogelj",

note = "Publisher Copyright: {\textcopyright} 2021 The Author(s) (2021). Published by Oxford University Press on behalf of the Guarantors of Brain.",

year = "2022",

month = feb,

day = "1",

doi = "10.1093/brain/awab300",

language = "English",

volume = "145",

pages = "684--699",

journal = "Brain",

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publisher = "Oxford University Press (OUP)",

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TY - JOUR

T1 - Interactome screening of C9orf72 dipeptide repeats reveals VCP sequestration and functional impairment by polyGA

AU - Bozič, Janja

AU - Motaln, Helena

AU - Janez, Anja Pucer

AU - Markič, Lara

AU - Tripathi, Priyanka

AU - Yamoah, Alfred

AU - Aronica, Eleonora

AU - Lee, Youn Bok

AU - Heilig, Raphael

AU - Fischer, Roman

AU - Thompson, Andrew J.

AU - Goswami, Anand

AU - Rogelj, Boris

PY - 2022/2/1

Y1 - 2022/2/1

N2 - Repeat expansions in the C9orf72 gene are a common cause of amyotrophic lateral sclerosis and frontotemporal lobar degeneration, two devastating neurodegenerative disorders. One of the proposed mechanisms of GGGGCC repeat expansion is their translation into non-canonical dipeptide repeats, which can then accumulate as aggregates and contribute to these pathologies. There are five different dipeptide repeat proteins (polyGA, polyGR, polyPR, polyPA and polyGP), some of which are known to be neurotoxic. In the present study, we used BioID2 proximity labelling to identify the interactomes of all five dipeptide repeat proteins consisting of 125 repeats each. We identified 113 interacting partners for polyGR, 90 for polyGA, 106 for polyPR, 25 for polyPA and 27 for polyGP. Gene Ontology enrichment analysis of the proteomic data revealed that these target interaction partners are involved in a variety of functions, including protein translation, signal transduction pathways, protein catabolic processes, amide metabolic processes and RNA-binding. Using autopsy brain tissue from patients with C9orf72 expansion complemented with cell culture analysis, we evaluated the interactions between polyGA and valosin containing protein (VCP). Functional analysis of this interaction revealed sequestration of VCP with polyGA aggregates, altering levels of soluble valosin-containing protein. VCP also functions in autophagy processes, and consistent with this, we observed altered autophagy in cells expressing polyGA. We also observed altered co-localization of polyGA aggregates and p62 in cells depleted of VCP. All together, these data suggest that sequestration of VCP with polyGA aggregates contributes to the loss of VCP function, and consequently to alterations in autophagy processes in C9orf72 expansion disorders.

AB - Repeat expansions in the C9orf72 gene are a common cause of amyotrophic lateral sclerosis and frontotemporal lobar degeneration, two devastating neurodegenerative disorders. One of the proposed mechanisms of GGGGCC repeat expansion is their translation into non-canonical dipeptide repeats, which can then accumulate as aggregates and contribute to these pathologies. There are five different dipeptide repeat proteins (polyGA, polyGR, polyPR, polyPA and polyGP), some of which are known to be neurotoxic. In the present study, we used BioID2 proximity labelling to identify the interactomes of all five dipeptide repeat proteins consisting of 125 repeats each. We identified 113 interacting partners for polyGR, 90 for polyGA, 106 for polyPR, 25 for polyPA and 27 for polyGP. Gene Ontology enrichment analysis of the proteomic data revealed that these target interaction partners are involved in a variety of functions, including protein translation, signal transduction pathways, protein catabolic processes, amide metabolic processes and RNA-binding. Using autopsy brain tissue from patients with C9orf72 expansion complemented with cell culture analysis, we evaluated the interactions between polyGA and valosin containing protein (VCP). Functional analysis of this interaction revealed sequestration of VCP with polyGA aggregates, altering levels of soluble valosin-containing protein. VCP also functions in autophagy processes, and consistent with this, we observed altered autophagy in cells expressing polyGA. We also observed altered co-localization of polyGA aggregates and p62 in cells depleted of VCP. All together, these data suggest that sequestration of VCP with polyGA aggregates contributes to the loss of VCP function, and consequently to alterations in autophagy processes in C9orf72 expansion disorders.

KW - ALS

KW - autophagy

KW - C9orf72

KW - VCP

UR - http://www.scopus.com/inward/record.url?scp=85122752285&partnerID=8YFLogxK

U2 - 10.1093/brain/awab300

DO - 10.1093/brain/awab300

M3 - Article

C2 - 34534264

AN - SCOPUS:85122752285

SN - 0006-8950

VL - 145

SP - 684

EP - 699

JO - Brain

JF - Brain

IS - 2

ER -

Interactome screening of C9orf72 dipeptide repeats reveals VCP sequestration and functional impairment by polyGA

Abstract

Keywords

UN SDGs

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