Cited by 1,413Ion Channels and ReceptorsMitochondrial Function and PathologyIon channel regulation and function

Chaperone-mediated coupling of endoplasmic reticulum and mitochondrial Ca2+ channels

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Szabadkai, György, Bianchi, Katiuscia, Várnai, Péter, De Stefani, Diego, Wieckowski, Mariusz R., Cavagna, Dario, Nagy, Anikó I., Balla, Tamás +1 more·2006·The Journal of Cell Biology

Abstract

The voltage-dependent anion channel (VDAC) of the outer mitochondrial membrane mediates metabolic flow, Ca2+, and cell death signaling between the endoplasmic reticulum (ER) and mitochondrial networks. We demonstrate that VDAC1 is physically linked to the endoplasmic reticulum Ca2+-release channel inositol 1,4,5-trisphosphate receptor (IP3R) through the molecular chaperone glucose-regulated protein 75 (grp75). Functional interaction between the channels was shown by the recombinant expression of the ligand-binding domain of the IP3R on the ER or mitochondrial surface, which directly enhanced Ca2+ accumulation in mitochondria. Knockdown of grp75 abolished the stimulatory effect, highlighting chaperone-mediated conformational coupling between the IP3R and the mitochondrial Ca2+ uptake machinery. Because organelle Ca2+ homeostasis influences fundamentally cellular functions and death signaling, the central location of grp75 may represent an important control point of cell fate and pathogenesis.

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Crossref · 10.1083/jcb.200608073

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  • IP3R and VDACs are MAM components that tether the ER to mitochondria through the molecular chaperone GRP75.

    “IP3R and VDACs are MAM components that tether the ER to mitochondria through the molecular chaperone GRP75 [95].”

    From Neuronal Apolipoprotein E4 Expression Results in Proteome-Wide Alterations and Compromises Bioenergetic Capacity by Disrupting Mitochondrial Function (2019) · cites this paper as [95]

    The ER–mitochondria interface section reports IP3R, VDAC1 and grp75 in the MAM fraction and a shared complex, with grp75 proposed to scaffold the two channels. The Discussion calls grp75 the key assembling molecule in their loose interaction. This supports channel coupling at the interface, but does not establish that the complex physically tethers the ER and mitochondria. (LLM, conf=0.83)

    Experimental — accuracy not yet measured
  • The physical SR-mitochondria interaction, assessed as the in situ protein-protein interaction between IP3R1 and VDAC1, was significantly lower in Tfam KO than in wild-type mice.

    “The physical SR-mitochondria interaction, assessed as the in situ protein-protein interaction between the SR Ca2+ channel inositol 1,3,4-triphosphate receptor 1 (IP3R1, also known as ITPR1) and the mitochondrial outer membrane voltage-dependent anion channel 1 (VDAC1) (Szabadkai et al., 2006), was significantly lower in Tfam KO than in wild-type mice (Fig. 6D).”
  • VDAC is present in MAMs, and StAR interacts with VDAC2 in steroidogenic cell model MAMs, an interaction necessary for its steroidogenic activity and mitochondrial import.

    “VDAC itself has been demonstrated to be present in MAMs (155), and, interestingly, StAR appears to interact with VDAC2 in steroidogenic cell model MAMs, an interaction necessary for its steroidogenic activity and mitochondrial import (156).”

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Research works printed but not linked: 1

  1. Varnai, P., A. Balla, L. Hunyady, and T. Balla. 2005. Targeted expression of the inositol 1,4,5-triphosphate receptor (IP3R) ligand-binding domain re- leases Ca2+ via endogenous IP3R channels. Proc. Natl. Acad. Sci. USA. 102:7859-7864.

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Authors
Szabadkai, G., Bianchi, K., Várnai, P., De Stefani, D., Wieckowski, M. R., Cavagna, D., Nagy, A. I., Balla, T., & Rizzuto, R.
Affiliations
  • 1Department of Experimental and Diagnostic Medicine, Section of General Pathology, Interdisciplinary Center for the Study of Inflammation, Emilia Romagna Laboratory for Genomics and Biotechnology, University of Ferrara, Ferrara 44100, Italy
  • University of Ferrara (IT)
  • Semmelweis University (HU)
  • Instytut Biologii Doświadczalnej im. Marcelego Nenckiego (PL)
  • 3Department of Physiology, Semmelweis University, Faculty of Medicine, Budapest, 1081 Hungary
  • 2Endocrinology and Reproduction Research Branch, National Institutes of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
Corresponding author
Rizzuto, Rosario
Venue
The Journal of Cell Biology
Published
2006-12-18
Volume
175
Issue
6
Pages
901-911
ISSN
  • 0021-9525 (ISSN-L)
  • 1540-8140
OpenAlex
W2096579721
Cited by
1,413
References
69
Citations by year
2026: 83 · 2025: 103 · 2024: 99 · 2023: 96 · 2022: 89 · 2021: 152 · 2020: 113 · 2019: 80 · 2018: 81 · 2017: 79 · 2016: 60 · 2015: 58 · 2014: 46 · 2013: 63 · 2012: 53
FWCI
11.62
Type
journal article
Language
en
Open access
Locations
  • The Journal of Cell Biology (publishedVersion)
  • PubMed Central (publishedVersion, cc-by-nc-sa)
  • PubMed (publishedVersion)
  • UCL Discovery (University College London) (submittedVersion)
  • Institutional Research Information System University of Ferrara (University of Ferrara) (submittedVersion, other-oa)
  • Padua Research Archive (University of Padova) (submittedVersion)
Funders
  • European Molecular Biology Laboratory
  • Associazione Italiana per la Ricerca sul Cancro
  • Medical Research Council
Topics
  • Life Sciences › Neuroscience › Sensory Systems › Ion Channels and Receptors
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Mitochondrial Function and Pathology
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Ion channel regulation and function
Keywords
VDAC1, IP3 receptor, endoplasmic reticulum, mitochondria, calcium release, calcium uptake, mitochondrial calcium homeostasis, cell death signaling, organelle communication
MeSH terms
Aequorin, Animals, Calcium, Endoplasmic Reticulum, HeLa Cells, Humans, Liver, Membrane Proteins, Mitochondria, Protein Conformation, Inositol 1,4,5-Trisphosphate, Molecular Chaperones, HSP70 Heat-Shock Proteins, Calcium Signaling, Two-Hybrid System Techniques, Voltage-Dependent Anion Channel 1, Mice, Rats, Inositol 1,4,5-Trisphosphate Receptors

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