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Synaptojanin1 (synj1) is a phosphoinositide phosphatase with dual SAC1 and 5'-phosphatase enzymatic activities in regulating phospholipid signaling. The brain-enriched isoform has been shown to participate in synaptic vesicle (SV) recycling. More recently, recessive human mutations were identified in the two phosphatase domains of SYNJ1, including R258Q, R459P and R839C, which are linked to rare forms of early-onset Parkinsonism. We now demonstrate that Synj1 heterozygous deletion (Synj1+/-), which is associated with an impaired 5'-phosphatase activity, also leads to Parkinson's disease (PD)-like pathologies in mice. We report that male Synj1+/- mice display age-dependent motor function abnormalities as well as alpha-synuclein accumulation, impaired autophagy and dopaminergic terminal degeneration. Synj1+/- mice contain elevated 5'-phosphatase substrate, PI(4,5)P2, particularly in the midbrain neurons. Moreover, pharmacological elevation of membrane PI(4,5)P2 in cultured neurons impairs SV endocytosis, specifically in midbrain neurons, and further exacerbates SV trafficking defects in Synj1+/- midbrain neurons. We demonstrate down-regulation of SYNJ1 transcript in a subset of sporadic PD brains, implicating a potential role of Synj1 deficiency in the decline of dopaminergic function during aging.
Assuntos
Proteínas do Tecido Nervoso/genética , Doença de Parkinson/genética , Monoéster Fosfórico Hidrolases/genética , alfa-Sinucleína/genética , Animais , Autofagia/genética , Modelos Animais de Doenças , Dopamina/genética , Dopamina/metabolismo , Neurônios Dopaminérgicos/metabolismo , Neurônios Dopaminérgicos/patologia , Endocitose/genética , Haploinsuficiência/genética , Humanos , Mesencéfalo/metabolismo , Mesencéfalo/patologia , Camundongos , Doença de Parkinson/patologia , Deleção de Sequência/genéticaRESUMO
Parkinson's disease (PD) is characterized pathologically by the selective loss of substantia nigra (SN) dopaminergic (DAergic) neurons. Recent evidence has suggested a role of LRRK2, linked to the most frequent familial PD, in regulating synaptic vesicle (SV) trafficking. However, the mechanism whereby LRRK2 mutants contribute to nigral vulnerability remains unclear. Here we show that the most common PD mutation LRRK2 G2019S impairs SV endocytosis in ventral midbrain (MB) neurons, including DA neurons, and the slowed endocytosis can be rescued by inhibition of LRRK2 kinase activity. A similar endocytic defect, however, was not observed in LRRK2 mutant neurons from the neocortex (hereafter, cortical neurons) or the hippocampus, suggesting a brain region-specific vulnerability to the G2019S mutation. Additionally, we found MB-specific impairment of SV endocytosis in neurons carrying heterozygous deletion of SYNJ1 (PARK20), a gene that is associated with recessive Parkinsonism. Combining SYNJ1+/- and LRRK2 G2019S does not exacerbate SV endocytosis but impairs sustained exocytosis in MB neurons and alters specific motor functions of 1-year-old male mice. Interestingly, we show that LRRK2 directly phosphorylates synaptojanin1 in vitro, resulting in the disruption of endophilin-synaptojanin1 interaction required for SV endocytosis. Our work suggests a merge of LRRK2 and SYNJ1 pathogenic pathways in deregulating SV trafficking in MB neurons as an underlying molecular mechanism of early PD pathogenesis.SIGNIFICANCE STATEMENT Understanding midbrain dopaminergic (DAergic) neuron-selective vulnerability in PD is essential for the development of targeted therapeutics. We report, for the first time, a nerve terminal impairment in SV trafficking selectively in MB neurons but not cortical neurons caused by two PARK genes: LRRK2 (PARK8) and SYNJ1 (PARK20). We demonstrate that the enhanced kinase activity resulting from the most frequent G2019S mutation in LRRK2 is the key to this impairment. We provide evidence suggesting that LRRK2 G2019S and SYNJ1 loss of function share a similar pathogenic pathway in deregulating DAergic neuron SV endocytosis and that they play additive roles in facilitating each other's pathogenic functions in PD.
Assuntos
Neurônios Dopaminérgicos/metabolismo , Endocitose , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/metabolismo , Mesencéfalo/metabolismo , Doença de Parkinson/genética , Vesículas Sinápticas/metabolismo , Animais , Mutação com Ganho de Função , Deleção de Genes , Células HEK293 , Hipocampo/citologia , Hipocampo/metabolismo , Humanos , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/genética , Masculino , Mesencéfalo/citologia , Camundongos , Camundongos Endogâmicos C57BL , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Doença de Parkinson/metabolismo , Monoéster Fosfórico Hidrolases/genética , Monoéster Fosfórico Hidrolases/metabolismoRESUMO
Standard alternating leg motions serve as the foundation for simple bipedal gaits, and the effectiveness of the fixed stimulus signal has been proved in recent studies. However, in order to address perturbations and imbalances, robots require more dynamic gaits. In this paper, we introduce dynamic stimulus signals together with a bipedal locomotion policy into reinforcement learning (RL). Through the learned stimulus frequency policy, we induce the bipedal robot to obtain both three-dimensional (3D) locomotion and an adaptive gait under disturbance without relying on an explicit and model-based gait in both the training stage and deployment. In addition, a set of specialized reward functions focusing on reliable frequency reflections is used in our framework to ensure correspondence between locomotion features and the dynamic stimulus. Moreover, we demonstrate efficient sim-to-real transfer, making a bipedal robot called BITeno achieve robust locomotion and disturbance resistance, even in extreme situations of foot sliding in the real world. In detail, under a sudden change in torso velocity of -1.2 m/s in 0.65 s, the recovery time is within 1.5-2.0 s.
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The limited lifespan of batteries is a challenge in the application of implantable electronic devices. Existing wireless power technologies such as ultrasound, near-infrared light and magnetic fields cannot charge devices implanted in deep tissues, resulting in energy attenuation through tissues and thermal generation. Herein, an ultra-low frequency magnetic energy focusing (ULFMEF) methodology was developed for the highly effective wireless powering of deep-tissue implantable devices. A portable transmitter was used to output the low-frequency magnetic field (<50 Hz), which remotely drives the synchronous rotation of a magnetic core integrated within the pellet-like implantable device, generating an internal rotating magnetic field to induce wireless electricity on the coupled coils of the device. The ULFMEF can achieve energy transfer across thick tissues (up to 20 cm) with excellent transferred power (4-15 mW) and non-heat effects in tissues, which is remarkably superior to existing wireless powering technologies. The ULFMEF is demonstrated to wirelessly power implantable micro-LED devices for optogenetic neuromodulation, and wirelessly charged an implantable battery for programmable electrical stimulation on the sciatic nerve. It also bypassed thick and tough protective shells to power the implanted devices. The ULFMEF thus offers a highly advanced methodology for the generation of wireless powered biodevices.
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Leucine-rich repeat kinase 2 (LRRK2) phosphorylates a subset of RAB GTPases, and the phosphorylation levels are elevated by Parkinson's disease (PD)-linked mutations of LRRK2. However, the precise function of the specific RAB GTPase targeted by LRRK2 signaling in the brain remains to be elucidated. Here, we identify RAB12 as a robust LRRK2 substrate in the mouse brains through phosphoproteomics profiling and solve the structure of RAB12-LRRK2 protein complex through Cryo-EM analysis. Mechanistically, RAB12 cooperates with LRRK2 to inhibit primary ciliogenesis and regulate centrosome homeostasis in astrocytes through enhancing the phosphorylation of RAB10 and recruiting Rab interacting lysosomal protein like 1 (RILPL1), while the functions of RAB12 require a direct interaction with LRRK2 and LRRK2 kinase activity. Furthermore, the ciliary deficits and centrosome alteration caused by the PD-linked LRRK2-G2019S mutation are prevented by the deletion of Rab12 in astrocytes. Thus, our study reveals a physiological function of the RAB12-LRRK2 complex in regulating ciliogenesis and centrosome homeostasis. The RAB12-LRRK2 structure offers a guidance in the therapeutic development of PD by targeting the RAB12-LRRK2 interaction.
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Parkinson's disease (PD) is the second most prevalent neurodegenerative disease and arises from dopamine (DA) neuron death selectively in the substantia nigra pars compacta (SNc). Rit2 is a reported PD risk allele, and recent single cell transcriptomic studies identified a major RIT2 cluster in PD DA neurons, potentially linking Rit2 expression loss to a PD patient cohort. However, it is still unknown whether Rit2 loss itself impacts DA neuron function and/or viability. Here we report that conditional Rit2 silencing in mouse DA neurons drove motor dysfunction that occurred earlier in males than females and was rescued at early stages by either inhibiting the DA transporter (DAT) or with L-DOPA treatment. Motor dysfunction was accompanied by decreased DA release, striatal DA content, phenotypic DAergic markers, DA neurons, and DAergic terminals, with increased pSer129-alpha synuclein and pSer935-LRRK2 expression. These results provide clear evidence that Rit2 loss is causal for SNc cell death and motor dysfunction, and reveal key sex-specific differences in the response to Rit2 loss.
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Soft electromagnetic devices have great potential in soft robotics and biomedical applications. However, existing soft-magneto-electrical devices would have limited hybrid functions and suffer from damaging stress concentrations, delamination or material leakage. Here, we report a hybrid magnetic-mechanical-electrical (MME) core-sheath fiber to overcome these challenges. Assisted by the coaxial printing method, the MME fiber can be printed into complex 2D/3D MME structures with integrated magnetoactive and conductive properties, further enabling hybrid functions including programmable magnetization, somatosensory, and magnetic actuation along with simultaneous wireless energy transfer. To demonstrate the great potential of MME devices, precise and minimally invasive electro-ablation was performed with a flexible MME catheter with magnetic control, hybrid actuation-sensing was performed by a durable somatosensory MME gripper, and hybrid wireless energy transmission and magnetic actuation were demonstrated by an untethered soft MME robot. Our work thus provides a material design strategy for soft electromagnetic devices with unexplored hybrid functions.
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Parkinson's disease (PD) is the second most prevalent neurodegenerative disease and arises from dopamine (DA) neuron death selectively in the substantia nigra pars compacta (SNc). Rit2 is a reported PD risk allele, and recent single cell transcriptomic studies identified a major RIT2 cluster in PD DA neurons, potentially linking Rit2 expression anomalies to a PD patient cohort. However, it is still unknown whether Rit2 loss itself is causative for PD or PD-like symptoms. Here we report that conditional Rit2 silencing in mouse DA neurons drove a progressive motor dysfunction that was more rapid in males than females and was rescued at early stages by either inhibiting the DA transporter (DAT) or with L-DOPA treatment. Motor dysfunction was accompanied by decreases in DA release, striatal DA content, phenotypic DAergic markers, and a loss of DA neurons, with increased pSer129-alpha synuclein expression. These results provide the first evidence that Rit2 loss is causal for SNc cell death and a PD-like phenotype, and reveal key sex-specific differences in the response to Rit2 loss.
RESUMO
Parkinson's disease (PD) is the second most prevalent neurodegenerative disease and arises from dopamine (DA) neuron death selectively in the substantia nigra pars compacta (SNc). Rit2 is a reported PD risk allele, and recent single cell transcriptomic studies identified a major RIT2 cluster in PD DA neurons, potentially linking Rit2 expression loss to a PD patient cohort. However, it is still unknown whether Rit2 loss itself is causative for PD or PD-like symptoms. Here we report that conditional Rit2 silencing in mouse DA neurons drove motor dysfunction that occurred earlier in males than females and was rescued at early stages by either inhibiting the DA transporter (DAT) or with L-DOPA treatment. Motor dysfunction was accompanied by decreased DA release, striatal DA content, phenotypic DAergic markers, DA neurons, and DAergic terminals, with increased pSer129-alpha synuclein and pSer935-LRRK2 expression. These results provide the first evidence that Rit2 loss is causal for SNc cell death and a PD-like phenotype, and reveal key sex-specific differences in the response to Rit2 loss.
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Insect life cycle is coordinated by hormones and their downstream effectors. Krüppel homolog1 (Kr-h1) is one of the crucial effectors which mediates the actions of the two critical hormones of insects, the juvenile hormone (JH) and 20-hydroxyecdysone (20E). It is a transcription factor with a DNA-binding motif of eight C2H2 zinc fingers which is found to be conserved among insect orders. The expression of Kr-h1 is fluctuant during insect development with high abundance in juvenile instars and lower levels in the final instar and pupal stage, and reappearance in adults, which is governed by the coordination of JH, 20E, and miRNAs. The dynamic expression pattern of Kr-h1 is closely linked to its function in the entire life of insects. Over the past several years, accumulating studies have advanced our understanding of the role of Kr-h1 during insect development. It acts as a universal antimetamorphic factor in both hemimetabolous and holometabolous species by directly inhibiting the transcription of 20E signaling genes Broad-Complex (Br-C) and Ecdysone induced protein 93F (E93), and steroidogenic enzyme genes involved in ecdysone biosynthesis. Meanwhile, it promotes vitellogenesis and ovarian development in the majority of studied insects. In addition, Kr-h1 regulates insect behavioral plasticity and caste identity, neuronal morphogenesis, maturation of sexual behavior, as well as embryogenesis and metabolic homeostasis. Hence, Kr-h1 acts as a cornerstone regulator in insect life.
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The global digital operation of finance has accelerated, and the transformation and upgrading of the financial industry has been fully empowered by digital technology, which has promoted the development of traditional financial industry toward green finance. Accelerating the pace of China's entry into the digital economy era has given the green financial industry new opportunities in its digital transformation. Therefore, the research reported in this paper selects provincial panel data and discusses the impact efficiency of the digital economy on green financial investment in China by static panel OLS and the threshold model method, and constructs a threshold model with regional industry scale and green financial audit as threshold variables. These steps are used to analyze the nonlinear characteristics of digital economy and green financial efficiency. The results show that the digital economy can improve the overall efficiency of China's green finance, and there are two threshold effects with regional industry scale as the threshold variable and one threshold effect with green financial audit support as the threshold variable. The results show that the development of a digital economy improved the investment efficiency of green finance in all provinces of China. In addition, through our research, we found that the application of the digital economy in green finance can reduce the imbalance of regional economic development. China should also strengthen the supervision of green auditing to promote the development of new green financial formats.
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Desenvolvimento Econômico , Eficiência , China , Indústrias , Investimentos em SaúdeRESUMO
Soft magneto-active machines capable of magnetically controllable shape-morphing and locomotion have diverse promising applications such as untethered biomedical robots. However, existing soft magneto-active machines often have simple structures with limited functionalities and do not grant high-throughput production due to the convoluted fabrication technology. Here, we propose a facile fabrication strategy that transforms 2D magnetic sheets into 3D soft magneto-active machines with customized geometries by incorporating origami folding. Based on automated roll-to-roll processing, this approach allows for the high-throughput fabrication of soft magneto-origami machines with a variety of characteristics, including large-magnitude deploying, sequential folding into predesigned shapes, and multivariant actuation modes (e.g., contraction, bending, rotation, and rolling locomotion). We leverage these abilities to demonstrate a few potential applications: an electronic robot capable of on-demand deploying and wireless charging, a mechanical 8-3 encoder, a quadruped robot for cargo-release tasks, and a magneto-origami arts/craft. Our work contributes for the high-throughput fabrication of soft magneto-active machines with multi-functionalities.
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Locomoção , RotaçãoRESUMO
Four-dimensional (4D) printed magnetoactive soft material (MASM) with a three-dimensional (3D) patterned magnetization profile possesses programmable shape transformation and controllable locomotion ability, showing promising applications in actuators and soft robotics. However, typical 4D printing strategies for MASM always introduced a printing magnetic field to orient the magneto-sensitive particles in polymers. Such strategies not only increase the cooperative control complexity of a 3D printer but may also induce local agglomeration of magneto-sensitive particles, which disturbs the magnetization of the already-printed structure. Herein, we proposed a novel 4D printing strategy that coupled the traditional 3D injection printing with the origami-based magnetization technique for easy fabrication of MASM objects with a 3D patterned magnetization profile. The 3D injection printing that can rapidly create complex 3D structures and the origami-based magnetization technique that can generate the spatial magnetization profile are combined for fabrication of 3D MASM objects to yield programmable transformation and controllable locomotion. A physics-based finite element model was also developed for the design guidance of origami-based magnetization and magnetic actuation transformation of MASM. We further demonstrated the diverse functions derived from the complex shape deformation of MASM-based robots, including a bionic human hand that played "rock-paper-scissors" game, a bionic butterfly that swung the wings on the flower, and a bionic turtle that crawled on the land and swam in the water.
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Magnetoactive soft material (MASM) is distinguished for multifunctional shape manipulations under magnetic actuation, thereby holding a great promise in soft robotics, actuators, electronics, and metamaterials. However, the current research of MASM with continuum hard-magnetic profiles focuses little on the transformation mechanism, high dimensional shape transformation, and multistable locomotion. Herein, we developed a systematic methodology for programmable transformation and controllable locomotion of MASM with 3D-patterned continuum magnetization. An iterative computational model based on the equilibrium between magnetic torque and deformation-induced elastic torque was developed for precise prediction of MASM transformation. Multidimensional and complex shape manipulation ability of MASM was demonstrated by magnetically actuated transformations, including 1D to 2D, 2D to 3D, and 3D to 4D transformations of solid MASM, 2D to 3D pattern transformation of MASM-based elastin-like mesh, and 3D to 4D transformation of MASM-based cuboidal lattice. Multistable and controllable locomotion of MASM was verified by multimodal locomotion behaviors of a scallop-inspired robot for wall climbing in a dry frame and drug delivery in wet stomach, including roll, open, and close under self-locked and unlocked states.
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Microglia maintain brain homeostasis by removing neuron-derived components such as myelin and cell debris. The evidence linking microglia to neurodegenerative diseases is growing; however, the precise mechanisms remain poorly understood. Herein, we report a neuroprotective role for microglia in the clearance of neuron-released α-synuclein. Neuronal α-synuclein activates microglia, which in turn engulf α-synuclein into autophagosomes for degradation via selective autophagy (termed synucleinphagy). Synucleinphagy requires the presence of microglial Toll-like receptor 4 (TLR4), which induces transcriptional upregulation of p62/SQSTM1 through the NF-κB signaling pathway. Induction of p62, an autophagy receptor, is necessary for the formation of α-synuclein/ubiquitin-positive puncta that are degraded by autophagy. Finally, disruption of microglial autophagy in mice expressing human α-synuclein promotes the accumulation of misfolded α-synuclein and causes midbrain dopaminergic neuron degeneration. Our study thus identifies a neuroprotective function of microglia in the clearance of α-synuclein via TLR4-NF-κB-p62 mediated synucleinphagy.
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Autofagia/fisiologia , Microglia/metabolismo , Doenças Neurodegenerativas/metabolismo , Receptor 4 Toll-Like/metabolismo , alfa-Sinucleína/metabolismo , Animais , Autoantígenos/metabolismo , Encéfalo/metabolismo , Modelos Animais de Doenças , Neurônios Dopaminérgicos/metabolismo , Feminino , Células HEK293 , Humanos , Mesencéfalo/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microglia/patologia , NF-kappa B/metabolismo , Transdução de SinaisRESUMO
Genetic and genomic studies have advanced our knowledge of inherited Parkinson's disease (PD), however, the etiology and pathophysiology of idiopathic PD remain unclear. Herein, we perform a meta-analysis of 8 PD postmortem brain transcriptome studies by employing a multiscale network biology approach to delineate the gene-gene regulatory structures in the substantia nigra and determine key regulators of the PD transcriptomic networks. We identify STMN2, which encodes a stathmin family protein and is down-regulated in PD brains, as a key regulator functionally connected to known PD risk genes. Our network analysis predicts a function of human STMN2 in synaptic trafficking, which is validated in Stmn2-knockdown mouse dopaminergic neurons. Stmn2 reduction in the mouse midbrain causes dopaminergic neuron degeneration, phosphorylated α-synuclein elevation, and locomotor deficits. Our integrative analysis not only begins to elucidate the global landscape of PD transcriptomic networks but also pinpoints potential key regulators of PD pathogenic pathways.
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Redes Reguladoras de Genes/genética , Doença de Parkinson/genética , Estatmina/genética , Substância Negra/metabolismo , Animais , Neurônios Dopaminérgicos , Perfilação da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Locomoção , Camundongos , Fosforilação , Transcriptoma , alfa-Sinucleína/metabolismoRESUMO
BACKGROUND: Dysfunctional autophagy is implicated in Alzheimer's Disease (AD) pathogenesis. The alterations in the expression of many autophagy related genes (ATGs) have been reported in AD brains; however, the disparity of the changes confounds the role of autophagy in AD. METHODS: To further understand the autophagy alteration in AD brains, we analyzed transcriptomic (RNAseq) datasets of several brain regions (BA10, BA22, BA36 and BA44 in 223 patients compared to 59 healthy controls) and measured the expression of 130 ATGs. We used autophagy-deficient mouse models to assess the impact of the identified ATGs depletion on memory, autophagic activity and amyloid-ß (Aß) production. RESULTS: We observed significant downregulation of multiple components of two autophagy kinase complexes BECN1-PIK3C3 and ULK1/2-FIP200 specifically in the parahippocampal gyrus (BA36). Most importantly, we demonstrated that deletion of NRBF2, a component of the BECN1-PIK3C3 complex, which also associates with ULK1/2-FIP200 complex, impairs memory in mice, alters long-term potentiation (LTP), reduces autophagy in mouse hippocampus, and promotes Aß accumulation. Furthermore, AAV-mediated NRBF2 overexpression in the hippocampus not only rescues the impaired autophagy and memory deficits in NRBF2-depleted mice, but also reduces ß-amyloid levels and improves memory in an AD mouse model. CONCLUSIONS: Our data not only implicates NRBF2 deficiency as a risk factor for cognitive impairment associated with AD, but also support the idea of NRBF2 as a potential therapeutic target for AD.
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Peptídeos beta-Amiloides/metabolismo , Proteínas Relacionadas à Autofagia/genética , Autofagia/fisiologia , Memória/fisiologia , Transativadores/genética , Doença de Alzheimer/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Encéfalo/metabolismo , Disfunção Cognitiva/patologia , Modelos Animais de Doenças , Transtornos da Memória/metabolismo , Camundongos , Camundongos Transgênicos , Neurônios/metabolismoRESUMO
The bHLH-PAS transcription factor, Methoprene-tolerant (Met)1, functions as a juvenile hormone (JH) receptor and transduces JH signals by directly binding to E-box like motifs in the regulatory regions of JH response genes. Nuclear localization of Met is crucial for its transcriptional activity. Our previous studies have shown that the chaperone protein Hsp83 facilitates JH-induced Met nuclear import in Drosophila melanogaster. However, the exact molecular mechanisms of Met nuclear transport are not fully elucidated. Using DNA affinity chromatography, we have previously detected binding of the nucleoporin Nup358, in the presence of JH, to the JH response region (JHRR) sequences isolated from the Krüppel-homolog 1 (Kr-h1) promoter. Here, we have demonstrated that Nup358 regulates JH-Hsp83-induced Met nuclear localization. RNAi-mediated knockdown of Nup358 expression in Drosophila fat body perturbs Met nuclear transport during the 3 h after initiation of wandering, when the JH titer is high. The accompanying reduced expression of the transport receptor importin ß in Nup358 RNAi flies could be one of the reasons accounting for Met mislocalization. Furthermore, a tetratricopeptide repeat (TPR) domain at the N-terminal end of Nup358 interacts with Hsp83 and is indispensable for Met nuclear localization. Overexpression of the TPR domain in Drosophila fat body prevents Met nuclear localization resulting in a decrease in JHRR-driven reporter activity and Kr-h1 expression. These data show that Nup358 facilitates JH-induced Met nuclear transport in a manner dependent on importin ß and Hsp83.