title: TROY interacts with Rho guanine nucleotide dissociation inhibitor α (RhoGDIα) to mediate Nogo-induced inhibition of neurite outgrowth.
abstract: TROY can functionally substitute p75 to comprise the Nogo receptor complex, which transduces the inhibitory signal of myelin-associated inhibitory factors on axon regeneration following CNS injury. The inhibition of neurite extension relies on TROY-dependent RhoA activation, but how TROY activates RhoA remains unclear. Here, we firstly identified Rho guanine nucleotide dissociation inhibitor α (RhoGDIα) as a binding partner of TROY using GST pull-down combined with two-dimensional gel electrophoresis and mass spectra analysis. The interaction was further confirmed by coimmunoprecipitation in vitro and in vivo. Deletion mutagenesis revealed that two regions of the TROY intracellular domain (amino acids 234-256 and 321-350) were essential for the interaction with RhoGDIα. Secondly, TROY and RhoGDIα were coexpressed in postnatal dorsal root ganglion neurons, cortex neurons, and cerebellar granule neurons (CGNs). Thirdly, TROY/RhoGDIα association was potentiated by Nogo-66 and was independent of p75/RhoGDIα interaction. Fourthly, TROY/RhoGDIα interaction was still able to activate RhoA when p75 was deficient. Furthermore, RhoA activation was decreased dramatically when TROY was knocked down in p75-deficient CGNs cells. Finally, RhoGDIα overexpression abolished RhoA activation and following neurite outgrowth inhibition by Nogo-66 in both wild-type and p75-deficient CGNs. These results showed that the association of RhoGDIα with TROY contributed to TROY-dependent RhoA activation and neurite outgrowth inhibition after Nogo-66 stimulation.
authors.affiliation: Institute of Neuroscience and Key Laboratory of Molecular Neurobiology, Ministry of Education, Neuroscience Research Centre of Changzheng Hospital, Second Military Medical University, Shanghai 200433, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Institute of Neuroscience and Key Laboratory of Molecular Neurobiology, Ministry of Education, Neuroscience Research Centre of Changzheng Hospital, Second Military Medical University, Shanghai 200433, China.
authors.forename: Xiujie
authors.initials: X
authors.lastname: Liu
authors.affiliation: Institute of Neuroscience and Key Laboratory of Molecular Neurobiology, Ministry of Education, Neuroscience Research Centre of Changzheng Hospital, Second Military Medical University, Shanghai 200433, China.
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Institute of Neuroscience and Key Laboratory of Molecular Neurobiology, Ministry of Education, Neuroscience Research Centre of Changzheng Hospital, Second Military Medical University, Shanghai 200433, China.
authors.forename: Aijun
authors.initials: A
authors.lastname: Huang
authors.affiliation: Institute of Neuroscience and Key Laboratory of Molecular Neurobiology, Ministry of Education, Neuroscience Research Centre of Changzheng Hospital, Second Military Medical University, Shanghai 200433, China.
authors.forename: Jiazhen
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Institute of Neuroscience and Key Laboratory of Molecular Neurobiology, Ministry of Education, Neuroscience Research Centre of Changzheng Hospital, Second Military Medical University, Shanghai 200433, China. Electronic address: chenghe@smmu.edu.cn.
authors.forename: Cheng
authors.initials: C
authors.lastname: He
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D006801:Humans; D051379:Mice; D009185:Myelin Proteins / Q000235:genetics / Q000378:metabolism*; D016501:Neurites / Q000378:metabolism*; D000070798:Nogo Proteins; D017434:Protein Structure, Tertiary; D051381:Rats; D017207:Rats, Sprague-Dawley; D018124:Receptors, Tumor Necrosis Factor / Q000235:genetics / Q000378:metabolism*; D017384:Sequence Deletion; D020741:rho GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism; D062948:rho Guanine Nucleotide Dissociation Inhibitor alpha / Q000235:genetics / Q000378:metabolism*; D020742:rhoA GTP-Binding Protein / Q000235:genetics / Q000378:metabolism
chemical_list: D009185:Myelin Proteins; D000070798:Nogo Proteins; C000603199:RTN4 protein, human; D018124:Receptors, Tumor Necrosis Factor; C000603201:Rtn4 protein, mouse; C000603197:Rtn4 protein, rat; C411850:TNFRSF19 protein, human; C409471:Tnfrsf19 protein, mouse; D062948:rho Guanine Nucleotide Dissociation Inhibitor alpha; C066737:RHOA protein, human; C526380:RhoA protein, mouse; D020741:rho GTP-Binding Proteins; D020742:rhoA GTP-Binding Protein
keywords: Cell Signaling; Neurite Outgrowth; Neurons; RhoA; Signaling