RESUMEN
Kindler epidermolysis bullosa is a genodermatosis that manifests with cutaneous and mucosal fragility and with photosensitivity. No cure is available to date. Kindlin-1, a deficient protein, binds to ß-integrin and is required for its activation. Using a previously established experimental workflow, we addressed the consequences of three naturally occurring pathogenic variants, leading either to single amino acid substitutions p.Y293D and p.W559R or to a single amino acid deletion p.I623del in kindlin-1. We show that p.Y293D disrupts kindlin-1 localization to focal adhesions and cell spreading. Although treatment with a chemical chaperone increases the amount of mutant protein, spreading does not improve, and cellular stress increases, whereas the variants p.W559R and p.I623del do not interfere with kindlin-1 localization to focal adhesions and support cell adhesion and survival. These mutants are also responsive to the treatment with a chemical chaperone, and the increased mutant proteins improve cell spreading. These findings suggest that low levels of mutant kindlins p.W559R and p.I623del are able to rescue some important cellular functions. Patients carrying these mutations could benefit from treatment with promotors of proteostasis. Our results show that each pathogenic variant must be individually tested on genetic, molecular, and cellular levels to tailor personalized treatments for patients.
