Transglutaminase Type 2 Regulates ER-Mitochondria Contact Sites by Interacting with GRP75

Autor: Manuela D’Eletto, Federica Rossin, Luca Occhigrossi, Maria Grazia Farrace, Danilo Faccenda, Radha Desai, Saverio Marchi, Giulia Refolo, Laura Falasca, Manuela Antonioli, Fabiola Ciccosanti, Gian Maria Fimia, Paolo Pinton, Michelangelo Campanella, Mauro Piacentini
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: Cell Reports, Vol 25, Iss 13, Pp 3573-3581.e4 (2018)
Druh dokumentu: article
ISSN: 2211-1247
DOI: 10.1016/j.celrep.2018.11.094
Popis: Summary: Transglutaminase type 2 (TG2) is a multifunctional enzyme that plays a key role in mitochondria homeostasis under stressful cellular conditions. TG2 interactome analysis reveals an enzyme interaction with GRP75 (glucose-regulated protein 75). GRP75 localizes in mitochondria-associated membranes (MAMs) and acts as a bridging molecule between the two organelles by assembling the IP3R-GRP75-VDAC complex, which is involved in the transport of Ca2+ from the endoplasmic reticulum (ER) to mitochondria. We demonstrate that the TG2 and GRP75 interaction occurs in MAMs. The absence of the TG2-GRP75 interaction leads to an increase of the interaction between IP3R-3 and GRP75; a decrease of the number of ER-mitochondria contact sites; an impairment of the ER-mitochondrial Ca2+ flux; and an altered profile of the MAM proteome. These findings indicate TG2 is a key regulatory element of the MAMs. : TG2 is an enzyme that plays a key role in mitochondria homeostasis. D’eletto et al. found that TG2 interacts with GRP75, a protein localized in mitochondria-associated membranes (MAMs). TG2 regulates the number of ER-mitochondria contact sites and Ca2+ flux, suggesting a key regulatory role in MAMs. Keywords: mitochondrial Ca2+, MAMs, GRP75, TG2, ER-mitochondria contact sites
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