Open AccessIdentification of proteins interacting with the mitochondrial small heat shock protein Hsp22 of Drosophila melanogaster: Implication in mitochondrial homeostasis
Author(s) -
Afrooz Dabbaghizadeh,
Geneviève Morrow,
Yasmine Ould Amer,
Étienne Hébert Chatelain,
Nicolas Pichaud,
Robert M. Tanguay
Publication year - 2018
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0193771
Subject(s) - hsp60 , mitochondrion , heat shock protein , mitochondrial matrix , microbiology and biotechnology , hsp70 , biology , drosophila melanogaster , chaperone (clinical) , dnaja3 , atp–adp translocase , hspa9 , mitochondrial dna , biochemistry , mitochondrial fusion , cytosol , inner mitochondrial membrane , gene , peptide sequence , medicine , pathology , enzyme
The small heat shock protein (sHsp) Hsp22 from Drosophila melanogaster (DmHsp22) is part of the family of sHsps in this diptera. This sHsp is characterized by its presence in the mitochondrial matrix as well as by its preferential expression during ageing. Although DmHsp22 has been demonstrated to be an efficient in vitro chaperone, its function within mitochondria in vivo remains largely unknown. Thus, determining its protein-interaction network (interactome) in the mitochondrial matrix would help to shed light on its function(s). In the present study we combined immunoaffinity conjugation (IAC) with mass spectroscopy analysis of mitochondria from HeLa cells transfected with DmHsp22 in non-heat shock condition and after heat shock (HS). 60 common DmHsp22-binding mitochondrial partners were detected in two independent IACs. Immunoblotting was used to validate interaction between DmHsp22 and two members of the mitochondrial chaperone machinery; Hsp60 and Hsp70. Among the partners of DmHsp22, several ATP synthase subunits were found. Moreover, we showed that expression of DmHsp22 in transiently transfected HeLa cells increased maximal mitochondrial oxygen consumption capacity and ATP contents, providing a mechanistic link between DmHsp22 and mitochondrial functions.