Neuronal RING finger protein 11 (RNF11) regulates canonical NF-κB signaling.

TitleNeuronal RING finger protein 11 (RNF11) regulates canonical NF-κB signaling.
Publication TypeJournal Article
Year of Publication2012
AuthorsPranski EL, Dalal NV, Herskowitz JH, Orr AL, Roesch LA, Fritz JJ, Heilman C, Lah JJ, Levey AI, Betarbet RS
JournalJ Neuroinflammation
Date Published2012 Apr 16
KeywordsAnimals, Carrier Proteins, Cell Line, Tumor, Cells, Cultured, Gene Knockdown Techniques, Humans, Mice, Mice, Inbred C57BL, Neurons, NF-kappa B, Signal Transduction

BACKGROUND: The RING domain-containing protein RING finger protein 11 (RNF11) is a member of the A20 ubiquitin-editing protein complex and modulates peripheral NF-κB signaling. RNF11 is robustly expressed in neurons and colocalizes with a population of α-synuclein-positive Lewy bodies and neurites in Parkinson disease patients. The NF-κB pathway has an important role in the vertebrate nervous system, where the absence of NF-κB activity during development can result in learning and memory deficits, whereas chronic NF-κB activation is associated with persistent neuroinflammation. We examined the functional role of RNF11 with respect to canonical NF-κB signaling in neurons to gain understanding of the tight association of inflammatory pathways, including NF-κB, with the pathogenesis of neurodegenerative diseases.

METHODS AND RESULTS: Luciferase assays were employed to assess NF-κB activity under targeted short hairpin RNA (shRNA) knockdown of RNF11 in human neuroblastoma cells and murine primary neurons, which suggested that RNF11 acts as a negative regulator of canonical neuronal NF-κB signaling. These results were further supported by analyses of p65 translocation to the nucleus following depletion of RNF11. Coimmunoprecipitation experiments indicated that RNF11 associates with members of the A20 ubiquitin-editing protein complex in neurons. Site-directed mutagenesis of the myristoylation domain, which is necessary for endosomal targeting of RNF11, altered the impact of RNF11 on NF-κB signaling and abrogated RNF11's association with the A20 ubiquitin-editing protein complex. A partial effect on canonical NF-κB signaling and an association with the A20 ubiquitin-editing protein complex was observed with mutagenesis of the PPxY motif, a proline-rich region involved in Nedd4-like protein interactions. Last, shRNA-mediated reduction of RNF11 in neurons and neuronal cell lines elevated levels of monocyte chemoattractant protein 1 and TNF-α mRNA and proteins, suggesting that NF-κB signaling and associated inflammatory responses are aberrantly regulated in the absence of RNF11.

CONCLUSIONS: Our findings support the hypothesis that, in the nervous system, RNF11 negatively regulates canonical NF-κB signaling. Reduced or functionally compromised RNF11 could influence NF-κB-associated neuronal functions, including exaggerated inflammatory responses that may have implications for neurodegenerative disease pathogenesis and progression.

Alternate JournalJ Neuroinflammation
PubMed ID22507528
PubMed Central IDPMC3416671
Grant ListP30NS055077 / NS / NINDS NIH HHS / United States
ES012870 / ES / NIEHS NIH HHS / United States
ES015777 / ES / NIEHS NIH HHS / United States
AG025688 / AG / NIA NIH HHS / United States
NS007480 / NS / NINDS NIH HHS / United States