title: Nuclear FAK promotes cell proliferation and survival through FERM-enhanced p53 degradation.
abstract: FAK is known as an integrin- and growth factor-associated tyrosine kinase promoting cell motility. Here we show that, during mouse development, FAK inactivation results in p53- and p21-dependent mesodermal cell growth arrest. Reconstitution of primary FAK-/-p21-/- fibroblasts revealed that FAK, in a kinase-independent manner, facilitates p53 turnover via enhanced Mdm2-dependent p53 ubiquitination. p53 inactivation by FAK required FAK FERM F1 lobe binding to p53, FERM F2 lobe-mediated nuclear localization, and FERM F3 lobe for connections to Mdm2 and proteasomal degradation. Staurosporine or loss of cell adhesion enhanced FERM-dependent FAK nuclear accumulation. In primary human cells, FAK knockdown raised p53-p21 levels and slowed cell proliferation but did not cause apoptosis. Notably, FAK knockdown plus cisplatin triggered p53-dependent cell apoptosis, which was rescued by either full-length FAK or FAK FERM re-expression. These studies define a scaffolding role for nuclear FAK in facilitating cell survival through enhanced p53 degradation under conditions of cellular stress.
authors.affiliation: Department of Reproductive Medicine, Moores Cancer Center, University of California, San Diego, 3855 Health Sciences Drive, MC0803, La Jolla, CA 92093, USA.
authors.forename: Ssang-Taek
authors.initials: ST
authors.lastname: Lim
authors.forename: Xiao Lei
authors.initials: XL
authors.lastname: Chen
authors.forename: Yangmi
authors.initials: Y
authors.lastname: Lim
authors.forename: Dan A
authors.initials: DA
authors.lastname: Hanson
authors.forename: Thanh-Trang
authors.initials: TT
authors.lastname: Vo
authors.forename: Kyle
authors.initials: K
authors.lastname: Howerton
authors.forename: Nicholas
authors.initials: N
authors.lastname: Larocque
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Fisher
authors.forename: David D
authors.initials: DD
authors.lastname: Schlaepfer
authors.forename: Dusko
authors.initials: D
authors.lastname: Ilic
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002455:Cell Division / Q000502:physiology; D002467:Cell Nucleus / Q000378:metabolism; D002470:Cell Survival / Q000502:physiology; D002945:Cisplatin / Q000494:pharmacology; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000172:deficiency / Q000235:genetics / Q000502:physiology; D047108:Embryonic Development / Q000235:genetics / Q000502:physiology; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D051417:Focal Adhesion Kinase 1 / Q000737:chemistry / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D008648:Mesoderm / Q000473:pathology; D051379:Mice; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D019311:Staurosporine / Q000494:pharmacology; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D025801:Ubiquitin / Q000378:metabolism; D054875:Ubiquitination
chemical_list: C493956:CDKN1A protein, human; C493957:Cdkn1a protein, mouse; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016159:Tumor Suppressor Protein p53; D025801:Ubiquitin; D051417:Focal Adhesion Kinase 1; C496050:PTK2 protein, human; C496051:Ptk2 protein, mouse; D046988:Proteasome Endopeptidase Complex; D019311:Staurosporine; D002945:Cisplatin