To investigate the usefulness of 18F-FP-CIT PET for assessing the severity of Parkinson's disease (PD) at various clinical stages, 41 patients with PD were divided into early (Hoehn&Yahr I-II, n = 23) and advanced (Hoehn & Yahr III-IV, n = 18) subgroups. 18F-FP-CIT PET was performed in these patients and 12 normal subjects. 18F-FP-CIT uptake in striatal subregions and its correlation with UPDRS were first evaluated by ROI analysis, and between-group differences were also analyzed by Statistical Parametric Mapping (SPM). Our results showed that striatal 18F-FP-CIT binding were significantly reduced to 70.9% (caudate), 46.8% (anterior putamen) and 24.0% (posterior putamen) in early PD compared with that of the control, and to 52.0%, 34.5% and 16.5% correspondingly in advanced PD, respectively. There was significant negative correlation between total motor UPDRS score of all parkinsonian patients and 18F-FP-CIT uptake in caudate nucleus (r = -0.53, p < 0.001), anterior putamen (r = -0.53, p < 0.001) and posterior putamen (r = -0.61, p < 0.001). SPM comparison of 18F-FP-CIT uptake between early or advanced PD and the control group showed significant decline in striatum, predominantly localized on the contralateral side and in the dorsal-posterior putamen. These results indicate that 18F-FP-CIT PET can serve as a suitable biomarker to represent the severity of PD in early and advanced stages.

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SummaryGram-negative phytopathogenic bacteria, such as Pseudomonas syringae, deliver multiple effector proteins into plant cells during infection. It is hypothesized that certain plant and mammalian effector proteins need to traverse the type III secretion system unfolded and are delivered into host cells as inactive enzymes. We have previously identified cyclophilin as the Arabidopsis eukaryotic activator of AvrRpt2, a P. syringae effector that is a cysteine protease. Cyclophilins are general folding catalysts and possess peptidyl-prolyl cis/trans isomerase (PPIase) activity. In this paper, we demonstrate the mechanism of AvrRpt2 activation by the Arabidopsis cyclophilin ROC1. ROC1 mutants lacking PPIase enzymatic activity were unable to activate AvrRpt2. Furthermore, nuclear magnetic resonance spectroscopy revealed a structural change in AvrRpt2 from an unfolded to a folded state in the presence of ROC1. Using in vitro binding assays, ROC1's consensus binding sequence was identified as GPxL, a motif present at four sites within AvrRpt2. The GPxL motifs are located in close proximity to AvrRpt2's catalytic triad and are required for protease activity both in vitro and in planta. These data suggest that after delivery into the plant cell during infection, cyclophilin binds AvrRpt2 at four sites and properly folds the effector protein by peptidyl-prolyl cis/trans isomerization.

FHA domains are phosphoThr recognition modules found in diverse signaling proteins, including kinase-associated protein phosphatase (KAPP) from Arabidopsis thaliana. The kinase-interacting FHA domain (KI-FHA) of KAPP targets it to function as a negative regulator of some receptor-like kinase (RLK) signaling pathways important in plant development and environmental responses. To aid in the identification of potential binding sites for the KI-FHA domain, we predicted (i) the structure of a representative KAPP-binding RLK, CLAVATA1, and (ii) the functional surfaces of RLK kinase domains using evolutionary trace analysis. We selected phosphopeptides from KAPP-binding Arabidopsis RLKs for in vitro studies of association with KI-FHA from KAPP. Three phosphoThr peptide fragments from the kinase domain of CLV1 or BAK1 were found to bind KI-FHA with KD values of 8-20 microM, by NMR or titration calorimetry. Their affinity is driven by favorable enthalpy and solvation entropy gain. Mutagenesis of these three threonine sites suggests Thr546 in the C-lobe of the BAK1 kinase domain to be a principal but not sole site of KI-FHA binding in vitro. The brassinosteroid receptor BRI1 and KAPP are shown to associate in vivo and in vitro. Further genetic studies indicate that KAPP may be a negative regulator of the BRI1 signaling transduction pathway. 15N-Labeled KI-FHA was titrated with the GST-BRI1 kinase domain and monitored by NMR. BRI1 interacts with the same 3/4, 4/5, 6/7, 8/9, and 10/11 recognition loops of KI-FHA, with similar affinity as the phosphoThr peptides.

Muon relaxation experiments reveal a slowly fluctuating magnetic field in the pseudogap phase of a cuprate superconductor.

Accumulation of α-synuclein (α-Syn) is a common pathology for both familiar and sporadic Parkinson's disease (PD), enhancing its clearance might be a promising strategy for treating PD. To assess the potential of trehalose in this regard, we investigated its effect on the PC12 cells overexpressing wild type (WT) or A53T mutant α-Syn and the implicated pathway it might mediated. We observed that trehalose promoted the clearance of A53T α-Syn but not WT α-Syn in PC12 cells, and confirmed the increased LC3 and Lysotracker RED positive autolysosomes by using lysotracker and LC3 staining, the enhanced expression of LC3-II in Western blot, and more autophagosomes under Transmission Electron Microscope in a dose dependent manner after the trehalose treatment. The activation of autophagy can be alleviated by applying macroautophagy inhibitor 3-methyladenine (3-MA). In addition, degradation of A53T and WT α-Syn was blocked after Ubiquitin Proteasome System (UPS) inhibitor (MG132) was applied in those PC12 cells overexpressing A53T or WT α-Syn, suggesting that A53T α-Syn could be degraded by both UPS and macroautophagy. But the effect of trehalose on A53T α-Syn is mainly mediated through the macroautophagy pathway, which is not a dominant way for WT α-Syn clearance. Further in vivo research will be needed to verify the effectiveness of trehalose in treating PD.

Forkhead-associated (FHA) domains are phosphoprotein-binding modules found in diverse signaling proteins that bind partners phosphorylated on threonine or serine. Kinase-associated protein phosphatase from Arabidopsis employs its FHA domain for negative regulation of receptor-like kinase signaling pathways, which are important in plant development. The solution structure of the free state of kinase-interacting FHA domain (KI-FHA) of kinaseassociated protein phosphatase has been determined with high precision and accuracy using residual dipolar couplings. KI-FHA is a sandwich of a five-stranded mixed ␤-sheet with a six-stranded antiparallel ␤-sheet. Despite homology only in the recognition loops, this fold is shared with FHA domains from checkpoint proteins from yeast and humans, as well as with nonhomologous MH2 domains of Smad tumor suppressors. A shared pattern of hydrophobicity throughout FHA domains and Smad MH2 domains may stabilize the core of the ␤-sandwich. Evolutionary trace analysis of FHA domains suggests class-specific residues in the recognition loops that could tune their phosphoprotein-binding specificity. This surface agrees with that of KI-FHA in contact with a phosphothreonine peptide ligand. Evolutionary trace analysis also predicts an unexpected swath of class-specific residues on another face of FHA domains. Protein interactions with these faces may affect assembly of transmembrane signaling complexes in plants, and in other FHA domain-containing assemblies. Signal transducing Ser͞Thr receptor-like protein kinases (RLKs) in plants, numbering 417 in Arabidopsis, were discovered based on their sequence similarity to receptor tyrosine kinases (1). RLKs play crucial roles in self-incompatibility, hormonal signaling, nodulation, abscission, systemic wound responses, and disease resistance in plants (1). The best characterized signaling component downstream of RLKs is kinaseassociated protein phosphatase (KAPP). It has an N-terminal type I membrane anchor, a kinase interaction domain, and a protein phosphatase type 2C (PP2C) catalytic domain (2). KAPP interacts with Arabidopsis RLKs, which include HAESA (formerly RLK5) (2), RLK4 (3), TMK1 (3), CLAVATA1 (4), WAK1 (5), FLS2 (6), SERK1 (7), BRI1, and BAK1 (J. Li, J. Wen, and J.C.W., unpublished work). KAPP is thought to bind phosphorylated serine or threonine of the kinase domain of CLAVATA1 to attenuate activation of CLAVATA1 through the PP2C activity of KAPP (2,4,8). The kinase interaction domain of KAPP is found on a 239-residue fragment spanning residues 98-336 (2). The minimal kinase interaction domain comprises the 119 amino acids from residue 180 to 298 that contains the FHA motif (9); this domain is designated hereafter as KI-FHA. Conserved residues in the FHA motif, i.e., Gly-211, Ser-226, His-229, and Asn-250 are essential for KI-FHA to bind phosphorylated RLKs (9).FHA motifs were suggested to be 55-75 residues long, with a glycine, arginine, serine, histidine, and asparagine conserved among three short blocks (10). The FHA motif is found i...

Objectives: In December 2019, a novel coronavirus disease (COVID-19) emerged in Wuhan city, China, which has subsequently led to a global pandemic. At the time of writing, COVID-19 in Wuhan appears to be in the final phase and under control. However, many other countries, especially the US, Italy and Spain, are still in the early phases and dealing with increasing cases every day. Therefore, this article aims to summarise and share the experience of controlling the spread of COVID-19 in Wuhan and provide effective suggestions to enable other countries to save lives. Study design: Data from the National Health Commission of China are used to investigate the evolution trajectory of COVID-19 in Wuhan and discuss the impacts of the intervention strategies. Methods: A four-stage modified Susceptible-Exposed-Infectious-Removed (SEIR) model is presented. This model considers many influencing factors, including chunyun (the Spring festival), sealing off the city and constructing the Fangcang shelter hospitals. In addition, a novel method is proposed to address the abnormal data on 12e13 February as a result of changing diagnostic criteria. Four different scenarios are considered to capture different intervention measures in practice. The exposed population in Wuhan who moved out before sealing off the city have also been identified, and an analysis on where they had gone was performed using the Baidu Migration Index. Results: The results demonstrate that the four-stage model was effective in forecasting the peak, size and duration of COVID-19. We found that the combined intervention measures are the only effective way to control the spread and not a single one of them can be omitted. We estimate that England will be another epicentre owing to its incorrect response at the initial stages of COVID-19. Fortunately, big data technology can help provide early warnings to new areas of the pandemic. Conclusions: The four-stage SEIR model was effective in capturing the evolution trajectory of COVID-19. Based on the model analysis, several effective suggestions are proposed to prevent and control the pandemic for countries that are still in the initial phases.