title: The tumor suppressor p53 guides GluA1 homeostasis through Nedd4-2 during chronic elevation of neuronal activity.
abstract: Chronic activity perturbation in neurons can trigger homeostatic mechanisms to restore the baseline function. Although the importance and dysregulation of neuronal activity homeostasis has been implicated in neurological disorders such as epilepsy, the complete signaling by which chronic changes in neuronal activity initiate the homeostatic mechanisms is unclear. We report here that the tumor suppressor p53 and its signaling are involved in neuronal activity homeostasis. Upon chronic elevation of neuronal activity in primary cortical neuron cultures, the ubiquitin E3 ligase, murine double minute- 2 (Mdm2), is phosphorylated by the kinase Akt. Phosphorylated Mdm2 triggers the degradation of p53 and subsequent induction of a p53 target gene, neural precursor cell expressed developmentally down-regulated gene 4-like (Nedd4-2). Nedd4-2 encodes another ubiquitin E3 ligase. We identified glutamate receptor subunit 1 (GluA1), subunit of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors as a novel substrate of Nedd4-2. The regulation of GluA1 level is known to be crucial for neuronal activity homeostasis. We confirmed that, by pharmacologically inhibiting Mdm2-mediated p53 degradation or genetically reducing Nedd4-2 in a mouse model, the GluA1 ubiquitination and down-regulation induced by chronically elevated neuronal activity are both attenuated. Our findings demonstrate the first direct function of p53 in neuronal homeostasis and elucidate a new mechanism by which cortical neurons respond to chronic activity perturbation.
authors.affiliation: Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: Jewett
authors.affiliation: Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
authors.forename: Jiuhe
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.|Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
authors.forename: Nien-Pei
authors.initials: NP
authors.lastname: Tsai
mesh_terms: D000818:Animals; D056827:Endosomal Sorting Complexes Required for Transport / Q000235:genetics* / Q000378:metabolism*; D006706:Homeostasis / Q000235:genetics* / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D000075702:Nedd4 Ubiquitin Protein Ligases; D009474:Neurons / Q000502:physiology*; D051058:Oncogene Protein v-akt / Q000235:genetics / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D051736:Proto-Oncogene Proteins c-mdm2; D018091:Receptors, AMPA / Q000235:genetics* / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics*; D044767:Ubiquitin-Protein Ligases / Q000235:genetics* / Q000378:metabolism*; D054875:Ubiquitination
chemical_list: D056827:Endosomal Sorting Complexes Required for Transport; D000075702:Nedd4 Ubiquitin Protein Ligases; D051058:Oncogene Protein v-akt; D051736:Proto-Oncogene Proteins c-mdm2; D018091:Receptors, AMPA; D016159:Tumor Suppressor Protein p53; D044767:Ubiquitin-Protein Ligases; C000618461:Nedd4l protein, mouse; C497207:Mdm2 protein, mouse
keywords: GluA1; Mdm2; Nedd4-2; neuronal activity; p53; ubiquitination