title: RNF11 sequestration of the E3 ligase SMURF2 on membranes antagonizes SMAD7 down-regulation of transforming growth factor β signaling.
abstract: The activity of the E3 ligase, SMURF2, is antagonized by an intramolecular, autoinhibitory interaction between its C2 and Hect domains. Relief of SMURF2 autoinhibition is induced by TGFβ and is mediated by the inhibitory SMAD, SMAD7. In a proteomic screen for endomembrane interactants of the RING-domain E3 ligase, RNF11, we identified SMURF2, among a cohort of Hect E3 ligases previously implicated in TGFβ signaling. Reconstitution of the SMURF2·RNF11 complexin vitrounexpectedly revealed robust SMURF2 E3 ligase activity, with biochemical properties previously restricted to the SMURF2·SMAD7 complex. Usingin vitrobinding assays, we find that RNF11 can directly compete with SMAD7 for SMURF2 and that binding is mutually exclusive and dependent on a proline-rich domain. Moreover, we found that co-expression of RNF11 and SMURF2 dramatically reduced SMURF2 ubiquitylation in the cell. This effect is strictly dependent on complex formation and sorting determinants that regulate the association of RNF11 with membranes. RNF11 is overexpressed in certain tumors, and, importantly, we found that depletion of this protein down-regulated gene expression of several TGFβ-responsive genes, dampened cell proliferation, and dramatically reduced cell migration in response to TGFβ. Our data suggest for the first time that the choice of binding partners for SMURF2 can sustain or repress TGFβ signaling, and RNF11 may promote TGFβ-induced cell migration.
authors.affiliation: From the Laura and Isaac Perlmutter Cancer Center at NYU Langone, New York, New York 10016.|the Albert Einstein School of Medicine, Bronx, New York 10461.
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Malonis
authors.affiliation: From the Laura and Isaac Perlmutter Cancer Center at NYU Langone, New York, New York 10016.|Biozentrum, University of Basel, 4056 Basel, Switzerland.
authors.forename: Wenxiang
authors.initials: W
authors.lastname: Fu
authors.affiliation: From the Laura and Isaac Perlmutter Cancer Center at NYU Langone, New York, New York 10016.|the Memorial Sloan Kettering Cancer Center, New York, New York 10065.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Jelcic
authors.affiliation: From the Laura and Isaac Perlmutter Cancer Center at NYU Langone, New York, New York 10016.
authors.forename: Marae
authors.initials: M
authors.lastname: Thompson
authors.affiliation: From the Laura and Isaac Perlmutter Cancer Center at NYU Langone, New York, New York 10016.|the Rutgers Biomedical and Health Sciences, Newark, New Jersey 07103, and.
authors.forename: Brian S
authors.initials: BS
authors.lastname: Canter
authors.affiliation: From the Laura and Isaac Perlmutter Cancer Center at NYU Langone, New York, New York 10016.|the Division of Cell Biology, Academy of Athens, Athens 11527, Greece.
authors.forename: Mary
authors.initials: M
authors.lastname: Tsikitis
authors.affiliation: From the Laura and Isaac Perlmutter Cancer Center at NYU Langone, New York, New York 10016.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Esteva
authors.affiliation: From the Laura and Isaac Perlmutter Cancer Center at NYU Langone, New York, New York 10016, Irma.Sanchez@nyumc.org.
authors.forename: Irma
authors.initials: I
authors.lastname: Sánchez
mesh_terms: D041721:3T3-L1 Cells; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000235:genetics / Q000378:metabolism; D002465:Cell Movement / Q000502:physiology; D004268:DNA-Binding Proteins; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D046912:Multiprotein Complexes / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D051906:Smad7 Protein / Q000235:genetics / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism*; D054875:Ubiquitination / Q000502:physiology
chemical_list: D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D046912:Multiprotein Complexes; C404508:RNF11 protein, human; C497806:SMAD7 protein, human; D051906:Smad7 Protein; D016212:Transforming Growth Factor beta; C471641:SMURF2 protein, human; D044767:Ubiquitin-Protein Ligases
keywords: E3 ubiquitin ligase; cancer; endosome; transforming growth factor beta (TGF-B); ubiquitylation (ubiquitination)