10779/crick.12571178.v1
Elisa Millana Fañanás
Elisa Millana
Fañanás
Sofia Todesca
Sofia
Todesca
Alessandro Sicorello
Alessandro
Sicorello
Laura Masino
Laura
Masino
Petr Pompach
Petr
Pompach
Francesca Magnani
Francesca
Magnani
Annalisa Pastore
Annalisa
Pastore
Andrea Mattevi
Andrea
Mattevi
On the mechanism of calcium-dependent activation of NADPH oxidase 5 (NOX5).
The Francis Crick Institute
2020
EF-hands
NMR
calcium activation
enzyme
structure
SB
NMR-ack
Biochemistry & Molecular Biology
0601 Biochemistry and Cell Biology
1101 Medical Biochemistry and Metabolomics
0304 Medicinal and Biomolecular Chemistry
2020-07-01 11:55:05
Journal contribution
https://crick.figshare.com/articles/journal_contribution/On_the_mechanism_of_calcium-dependent_activation_of_NADPH_oxidase_5_NOX5_/12571178
It is now accepted that reactive oxygen species (ROS) are not only dangerous oxidative agents but also chemical mediators of the redox cell signaling and innate immune response. A central role in ROS-controlled production is played by the NADPH oxidases (NOXs), a group of seven membrane-bound enzymes (NOX1-5 and DUOX1-2) whose unique function is to produce ROS. Here, we describe the regulation of NOX5, a widespread family member present in cyanobacteria, protists, plants, fungi, and the animal kingdom. We show that the calmodulin-like regulatory EF-domain of NOX5 is partially unfolded and detached from the rest of the protein in the absence of calcium. In the presence of calcium, the C-terminal lobe of the EF-domain acquires an ordered and more compact structure that enables its binding to the enzyme dehydrogenase (DH) domain. Our spectroscopic and mutagenesis studies further identified a set of conserved aspartate residues in the DH domain that are essential for NOX5 activation. Altogether, our work shows that calcium induces an unfolded-to-folded transition of the EF-domain that promotes direct interaction with a conserved regulatory region, resulting in NOX5 activation.