eNOS S-nitrosylates β-actin on Cys374 and regulates PKC-θ at the immune synapse by impairing actin binding to profilin-1

• DOI: 10.1371/journal.pbio.2000653
• Publication Date: 2017-04-10T13:23:51Z
• Authors: Almudena García-O...; Noa B. Martín-Cof...; Sales Ibiza; Ángel Ortega; Alicia Izquierdo-...; Antonio Trullo; Víctor M. Victor; Enrique Calvo; Begoña Sot; Antonio Martínez-...; Jesús Vázquez; Francisco Sánchez...; Juan M. Serrador
• Keywords: Profilin; Immunological synapse; Actin remodeling

The actin cytoskeleton coordinates the organization of signaling microclusters at immune synapse (IS); however, mechanisms involved remain poorly understood. We show here that nitric oxide (NO) generated by endothelial synthase (eNOS) controls coalescence protein kinase C-θ (PKC-θ) central supramolecular activation cluster (c-SMAC) IS. eNOS translocated with Golgi to IS and partially colocalized F-actin around c-SMAC. This resulted in reduced polymerization centripetal retrograde flow β-actin PKC-θ from lamellipodium-like distal (d)-SMAC, promoting activation. Furthermore, eNOS-derived NO S-nitrosylated on Cys374 impaired binding profilin-1 (PFN1), as confirmed transnitrosylating agent S-nitroso-L-cysteine (Cys-NO). importance formation PFN1-actin complexes regulation was corroborated overexpression PFN1- actin-binding defective mutants (C374S) PFN1 (H119E), respectively, which These findings unveil a novel NO-dependent mechanism