P 085 - Characterization of vimentin-zinc interaction and its impact on the response to electrophilic and oxidative stress

Abstract

Vimentin is an intermediate filament protein expressed in mesenchymal cells, playing a key role in organelle positioning, cell migration and signalling. Several electrophiles and oxidants target vimentin, mainly through its cysteine residue C328, causing network reorganization. Our previous studies suggest that cellular zinc availability may function as a reversible switch controlling vimentin dynamics and susceptibility to oxidants. Thus, we aimed to characterize the interaction between vimentin and zinc, and to understand its protective role against oxidative and electrophilic stress. We have observed that micromolar zinc induces vimentin polymerization in vitro, as assessed by centrifugation and light scattering assays, which is reversed by zinc chelators, such as EDTA and TPEN. Several crosslinking agents induce vimentin oligomerization. Remarkably, preincubation with zinc selectively protects vimentin from cysteine crosslinking with dibromobimane (DBB), whereas amino group crosslinking by disuccinimidyl tartrate (DST) is not affected. Incubation with zinc also protects vimentin from modification by several electrophilic lipids, an effect that is not mimicked by other divalent cations, like magnesium. These results illustrate an avid interaction between vimentin and zinc in vitro, which could be important for vimentin dynamics and response to oxidants and electrophiles.