On the mechanism of calcium-dependent activation of NADPH oxidase 5 (NOX5)

0559327 - MBÚ 2023 RIV GB eng J - Journal Article
Fananas, E. M. - Todesca, S. - Sicorello, A. - Masino, L. - Pompach, Petr - Magnani, F. - Pastore, A. - Mattevi, A.
On the mechanism of calcium-dependent activation of NADPH oxidase 5 (NOX5).
FEBS Journal. Roč. 287, č. 12 (2020), s. 2486-2503. ISSN 1742-464X. E-ISSN 1742-4658
EU Projects: European Commission(XE) 731077 - EU_FT-ICR_MS
Research Infrastructure: CIISB - 90043
Institutional support: RVO:61388971
Keywords : calcium activation * EF-hands * enzyme * nmr * structure
OECD category: Microbiology
Impact factor: 5.542, year: 2020
Method of publishing: Open access
https://febs.onlinelibrary.wiley.com/doi/10.1111/febs.15160

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.
Permanent Link: https://hdl.handle.net/11104/0332657