Schneider, TaianeMartinez-Martinez, ArturoCubillos Rojas, MónicaBartrons Bach, RamonVentura Pujol, FrancescRosa López, José Luis2018-11-092018-11-092018-07-311949-2553https://hdl.handle.net/2445/125949The RAF/MEK/ERK cascade is a conserved intracellular signaling pathway that controls fundamental cellular processes including growth, proliferation, differentiation, survival and migration. Aberrant regulation of this signaling pathway has long been associated with human cancers. A major point of regulation of this pathway occurs at the level of the serine/threonine protein kinase C-RAF. Here, we show how the E3 ubiquitin ligase HERC1 regulates ERK signaling. HERC1 knockdown induced cellular proliferation, which is associated with an increase in ERK phosphorylation and in C-RAF protein levels. We demonstrate that overexpression of wild-type C-RAF is sufficient to increase ERK phosphorylation. Experiments with pharmacological inhibitors of RAF activity, or with interference RNA, show that the regulation of ERK phosphorylation by HERC1 is RAF-dependent. Immunoprecipitation, pull-down and confocal fluorescence microscopy experiments demonstrate an interaction between HERC1 and C-RAF proteins. Mechanistically, HERC1 controls C-RAF stability by regulating its polyubiquitylation in a lysine 48-linked chain. In vitro ubiquitylation assays indicate that C-RAF is a substrate of the E3 ubiquitin ligase HERC1. Altogether, we show how HERC1 can regulate cell proliferation through the activation of ERK signaling by a mechanism that affects C-RAF's stability.18 p.application/pdfengcc-by (c) Schneider, Taiane et al., 2018http://creativecommons.org/licenses/by/3.0/esUbiqüitinaProteïnes de membranaTransducció de senyal cel·lularRegulació cel·lularUbiquitinMembrane proteinsCellular signal transductionCellular control mechanismsinfo:eu-repo/semantics/article6815142018-11-09info:eu-repo/semantics/openAccess30140388