Stability of a stationary solution for the Lugiato-Lefever equation

We study the stability of a stationary solution for the Lugiato-Lefever equation with the periodic boundary condition in one space dimension, which is a damped and driven nonlinear Schrodinger equation introduced to model the optical cavity. In this paper, we prove the Strichartz estimates for the linear damped Schrodinger equation with potential and external forcing and investigate the stability of certain stationary solutions under the initial perturbation within the framework of $L^2$

Fas palmitoylation by the palmitoyl acyltransferase DHHC7 regulates Fas stability

International audienceThe death receptor Fas undergoes a variety of post-translational modifications including S-palmitoylation. This protein acylation has been reported essential for an optimal cell death signaling by allowing both a proper Fas localization in cholesterol and sphingolipid-enriched membrane nanodomains, as well as Fas high-molecular weight complexes. In human, S-palmitoylation is controlled by 23 members of the DHHC family through their palmitoyl acyltransferase activity. In order to better understand the role of this post-translational modification in the regulation of the Fas-mediated apoptosis pathway, we performed a screen that allowed the identification of DHHC7 as a Fas-palmitoylating enzyme. Indeed, modifying DHHC7 expression by specific silencing or overexpression, respectively, reduces or enhances Fas palmitoylation and DHHC7 co-immunoprecipitates with Fas. At a functional level, DHHC7-mediated palmitoylation of Fas allows a proper Fas expression level by preventing its degradation through the lysosomes. Indeed, the decrease of Fas expression obtained upon loss of Fas palmitoylation can be restored by inhibiting the lysosomal degradation pathway. We describe the modification of Fas by palmitoylation as a novel mechanism for the regulation of Fas expression through its ability to circumvent its degradation by lysosomal proteolysis