Disulfide-mediated tetramerization of TRAP1 fosters its antioxidant and pro-neoplastic activities.

Abstract

The mitochondrial chaperone TRAP1 exerts a protective function in cells exposed to diverse stress conditions in both physiological and pathological contexts. In cancer cells, it contributes to neoplastic progression ensuing metabolic rewiring and protection from oxidative insults. TRAP1 works as a homodimer, but recent evidence has indicated that it can form tetramers whose functional effects remain elusive. Here, we find that TRAP1 forms redox-sensitive tetramers via disulfide bonds involving two critical cysteine residues, C261 and C573. TRAP1 tetramerization is elicited by oxidative stress and abrogated upon expression of the double C261S/C573R mutant. In cancer contexts, the expression of the TRAP1 C261S/C573R mutant is unable to inhibit the activity of its client succinate dehydrogenase and to confer protection against oxidative insults, and it hampers invasiveness of aggressive sarcoma cells. Our data indicate that TRAP1 undergoes tetramerization in response to oxidative stress and identify C261 and C573 as critical for TRAP1 structural rearrangement and for functions.