Merlin/NF2 functions upstream of the nuclear E3 ubiquitin ligase CRL4 DCAF1 to suppress oncogenic gene expression Journal Article


Authors: Cooper, J.; Li, W.; You, L.; Schiavon, G.; Pepe-Caprio, A.; Zhou, L.; Ishii, R.; Giovannini, M.; Hanemann, C. O.; Long, S. B.; Erdjument-Bromage, H.; Zhou, P.; Tempst, P.; Giancotti, F. G.
Article Title: Merlin/NF2 functions upstream of the nuclear E3 ubiquitin ligase CRL4 DCAF1 to suppress oncogenic gene expression
Abstract: Integrin-mediated activation of PAK (p21-activated kinase) causes phosphorylation and inactivation of the FERM (4.1, ezrin, radixin, moesin) domain - containing protein Merlin, which is encoded by the NF2 (neurofibromatosis type 2) tumor suppressor gene. Conversely, cadherin engagement inactivates PAK, thus leading to accumulation of unphosphorylated Merlin. Current models imply that Merlin inhibits cell proliferation by inhibiting mitogenic signaling at or near the plasma membrane. We have recently shown that the unphosphorylated, growth-inhibiting form of Merlin accumulates in the nucleus and binds to the E3 ubiquitin ligase CRL4DCAF1 to suppress its activity. Depletion of DCAF1 blocks the hyperproliferation caused by inactivation of Merlin. Conversely, expression of a Merlin-insensitive DCAF1 mutant counteracts the antimitogenic effect of Merlin. Expression of Merlin or silencing of DCAF1 in Nf2-deficient cells induce an overlapping, tumor-suppressive program of gene expression. Mutations present in some tumors from NF2 patients disrupt Merlin's ability to interact with or inhibit CRL 4DCAF1. Lastly, depletion of DCAF1 inhibits the hyperproliferation of Schwannoma cells isolated from NF2 patients and suppresses the oncogenic potential of Merlin-deficient tumor cell lines. Current studies are aimed at identifying the substrates and mechanism of action of CRL4DCAF1 and examining its role in NF2-dependent tumorigenesis in mouse models. We propose that Merlin mediates contact inhibition and suppresses tumorigenesis by translocating to the nucleus to inhibit CRL4DCAF1.
Keywords: signal transduction; protein expression; protein phosphorylation; unclassified drug; mutation; conference paper; mutant protein; protein domain; cell proliferation; mouse; animal; animals; mice; gene; gene expression; ubiquitin protein ligase; protein protein interaction; mitogenesis; cancer cell culture; enzymology; phosphorylation; cancer model; physiology; carcinogenesis; oncogenes; gene expression regulation; oncogene; tumor suppressor gene; enzyme inactivation; cell membrane; cell nucleus; ubiquitin protein ligase e3; nuclear localization signal; ubiquitin-protein ligases; bioaccumulation; merlin; p21 activated kinase; nf2 gene; neurofibromin 2; ezrin; moesin; radixin; neurilemoma; protein crl4 dcaf1
Journal Title: Science Signaling
Volume: 4
Issue: 188
ISSN: 1945-0877
Publisher: American Association for the Advancement of Science  
Date Published: 2011-08-30
Start Page: pt6
Language: English
DOI: 10.1126/scisignal.2002314
PROVIDER: scopus
PUBMED: 21878678
DOI/URL:
Notes: --- - "Export Date: 3 October 2011" - "Source: Scopus"
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MSK Authors
  1. Liru You
    3 You
  2. Paul J Tempst
    324 Tempst
  3. Stephen Barstow Long
    34 Long
  4. Wei Li
    6 Li
  5. Jonathan F Cooper
    9 Cooper