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Tucker JD, Ong J, Conserve D, Pan S, Tang W. Scaling up HIV self-testing in China and Africa. J Virus Erad 2017. [DOI: 10.1016/s2055-6640(20)30337-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Tucker JD, Ong J, Conserve D, Pan S, Tang W. Scaling up HIV self-testing in China and Africa. J Virus Erad 2017; 3:167. [PMID: 28758026 PMCID: PMC5518247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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78
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Pan S, Raby S, Anandadas C, Magee B. Cardiac dose constraints for left-sided breast irradiation: RCR guidelines - idealistic or realistic? Clin Oncol (R Coll Radiol) 2017. [DOI: 10.1016/j.clon.2017.04.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Yañez O, Vásquez-Espinal A, Pino-Rios R, Ferraro F, Pan S, Osorio E, Merino G, Tiznado W. Exploiting electronic strategies to stabilize a planar tetracoordinate carbon in cyclic aromatic hydrocarbons. Chem Commun (Camb) 2017; 53:12112-12115. [DOI: 10.1039/c7cc06248f] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new approach to stabilize compounds containing a planar tetracoordinate carbon (ptC), embedded in aromatic hydrocarbons, is presented herein.
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Che S, Xi R, Pan S, Chen X, Hui B, Fu S, Guo J, Zhang X. HPV16 E6-E7 Induces Cancer Stem-like Cell Phenotypes and Chemoradioresistance in Esophageal Squamous Cell Carcinoma Through Activation of PI3K/Akt Signaling Pathway. Int J Radiat Oncol Biol Phys 2016. [DOI: 10.1016/j.ijrobp.2016.06.2027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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81
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Pan S, Honig S. Variability of male fertility nutriceuticals: supplement analysis, cost and quality control. Fertil Steril 2016. [DOI: 10.1016/j.fertnstert.2016.07.832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Zhang ZM, Ma KW, Yuan S, Luo Y, Jiang S, Hawara E, Pan S, Ma W, Song J. Structure of a pathogen effector reveals the enzymatic mechanism of a novel acetyltransferase family. Nat Struct Mol Biol 2016; 23:847-52. [PMID: 27525589 DOI: 10.1038/nsmb.3279] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 07/19/2016] [Indexed: 02/07/2023]
Abstract
Effectors secreted by the type III secretion system are essential for bacterial pathogenesis. Members of the Yersinia outer-protein J (YopJ) family of effectors found in diverse plant and animal pathogens depend on a protease-like catalytic triad to acetylate host proteins and produce virulence. However, the structural basis for this noncanonical acetyltransferase activity remains unknown. Here, we report the crystal structures of the YopJ effector HopZ1a, produced by the phytopathogen Pseudomonas syringae, in complex with the eukaryote-specific cofactor inositol hexakisphosphate (IP6) and/or coenzyme A (CoA). Structural, computational and functional characterizations reveal a catalytic core with a fold resembling that of ubiquitin-like cysteine proteases and an acetyl-CoA-binding pocket formed after IP6-induced structural rearrangements. Modeling-guided mutagenesis further identified key IP6-interacting residues of Salmonella effector AvrA that are required for acetylating its substrate. Our study reveals the structural basis of a novel class of acetyltransferases and the conserved allosteric regulation of YopJ effectors by IP6.
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Xu Y, Zhuang L, Kang H, Ma P, Xu T, Pan S, Gu B. Prevalence, resistance patterns, and characterization of integrons of Shigella flexneri isolated from Jiangsu Province in China, 2001-2011. Eur J Clin Microbiol Infect Dis 2016; 35:1347-53. [PMID: 27220330 DOI: 10.1007/s10096-016-2671-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 05/04/2016] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To provide the epidemiology, resistance pattern, and characterization of integrons in Shigella flexneri isolated between 2001 and 2011 in Jiangsu Province. METHOD A total of 624 strains of S. flexneri were collected from both outpatients and inpatients in hospitals in Jiangsu Province from January 2001 to December 2011. The Kirby-Bauer disk diffusion method was used to perform the antimicrobial susceptibility test. Polymerase chain reaction (PCR) was used in the detection of integrons. Pulsed-field gel electrophoresis (PFGE) was applied in the homology studies. RESULT Serotype 2a accounted for the largest proportion in S. flexneri, namely 26.4 %. Notably, an increasing trend was detected in the resistance to common antimicrobial agents during the period 2001-2011. In recent years, more than 80.0 % isolates of S. flexneri have proved to be resistant to ampicillin, nalidixic acid, and tetracycline. The positive rates of class 1, class 2, and the atypical class 1 integrons in S. flexneri are 69.3 %, 87.8 %, and 89.2 % respectively. Most integrons detected in our research carry genes encoding resistance to trimethoprim and streptomycin. CONCLUSION Antimicrobial resistance in S. flexneri has demonstrated a continuous rising trend in Jiangsu Province. A high prevalence of integrons and gene cassettes play an important role in the transmission of drug resistance in S. flexneri. Effective measures are urgently needed to control the spread of multi-drug-resistant S. flexneri, and more continuing active surveillance of antimicrobial resistance should be established worldwide, especially in developing countries.
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Pan S, Li TING, Olvera de la Cruz M. Molecular dynamics simulation of DNA-directed assembly of nanoparticle superlattices using patterned templates. ACTA ACUST UNITED AC 2016. [DOI: 10.1002/polb.24073] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Yang B, Hao X, Zeng X, Ji T, Pan S, Feng Y. Correlation between chromosome 1p/19q status and VEGF mRNA expression in gliomas. GENETICS AND MOLECULAR RESEARCH 2016; 15:gmr7322. [DOI: 10.4238/gmr.15017322] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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86
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Pan S, Kumar V, Parikh O, Charnley N, Birtle A. 246P The sequencing conundrum in metastatic castrate resistant prostate cancer (mCRPC): The Rosemere Cancer Centre experience to unlocking the optimal sequence. Ann Oncol 2015. [DOI: 10.1093/annonc/mdv524.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Ma KW, Jiang S, Hawara E, Lee D, Pan S, Coaker G, Song J, Ma W. Two serine residues in Pseudomonas syringae effector HopZ1a are required for acetyltransferase activity and association with the host co-factor. THE NEW PHYTOLOGIST 2015; 208:1157-68. [PMID: 26103463 PMCID: PMC4768790 DOI: 10.1111/nph.13528] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Accepted: 05/21/2015] [Indexed: 05/21/2023]
Abstract
Gram-negative bacteria inject type III secreted effectors (T3SEs) into host cells to manipulate the immune response. The YopJ family effector HopZ1a produced by the plant pathogen Pseudomonas syringae possesses acetyltransferase activity and acetylates plant proteins to facilitate infection. Using mass spectrometry, we identified a threonine residue, T346, as the main autoacetylation site of HopZ1a. Two neighboring serine residues, S349 and S351, are required for the acetyltransferase activity of HopZ1a in vitro and are indispensable for the virulence function of HopZ1a in Arabidopsis thaliana. Using proton nuclear magnetic resonance (NMR), we observed a conformational change of HopZ1a in the presence of inositol hexakisphosphate (IP6), which acts as a eukaryotic co-factor and significantly enhances the acetyltransferase activity of several YopJ family effectors. S349 and S351 are required for IP6-binding-mediated conformational change of HopZ1a. S349 and S351 are located in a conserved region in the C-terminal domain of YopJ family effectors. Mutations of the corresponding serine(s) in two other effectors, HopZ3 of P. syringae and PopP2 of Ralstonia solanacerum, also abolished their acetyltransferase activity. These results suggest that, in addition to the highly conserved catalytic residues, YopJ family effectors also require conserved serine(s) in the C-terminal domain for their enzymatic activity.
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Pan S, Bahl A, Gee A, Butt M, Malik Z, Dew R, Birtle A. 2552 Real Life treatment sequences and survival of men with metastatic castrate-resistant prostate cancer (mCRPC) receiving cabazitaxel in UK clinical practice. Eur J Cancer 2015. [DOI: 10.1016/s0959-8049(16)31371-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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89
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He CH, Pan S, Ma YT, Yang YN, Ma X, Li XM, Xie X, Chen Y, Yu ZX, Chen BD, Zheng YY, Liu F. Optimal waist-to-height ratio cutoff values for predicting cardio-metabolic risk in Han and Uygur adults in northwest part of China. Eur J Clin Nutr 2015; 69:954-60. [DOI: 10.1038/ejcn.2015.25] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Revised: 01/08/2015] [Accepted: 01/31/2015] [Indexed: 12/23/2022]
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He L, Pan S, Li Y, Zhang L, Zhang W, Yi H, Song C, Niu Y. Increased proliferation and adhesion properties of human dental pulp stem cells in PLGA scaffolds via simulated microgravity. Int Endod J 2015; 49:161-73. [PMID: 25702704 DOI: 10.1111/iej.12441] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Accepted: 02/16/2015] [Indexed: 01/09/2023]
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Zheng Y, Pan S, Huang Y, Ci L, Zhao R, Yang X. Breed-specific lipid-related gene expression in the subcutaneous fat of Large White and Erhualian pigs at weaning. Arch Anim Breed 2015. [DOI: 10.5194/aab-58-33-2015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Abstract. The Erhualian (EHL) pig possesses significantly lower growth rates and higher adipose deposition compared with the Large White (LW) pig. To further understand the mechanism of breed lipid deposition difference at the early postnatal age, we employed an animal model of EHL and LW pigs at weaning age to compare the lipid metabolism differences in subcutaneous fat. The result showed that serum triglyceride in EHL was significantly higher (P < 0.05) than that of LW. Peroxisome proliferator-activated receptor-γ protein level in EHL was significantly higher (P < 0.01) though CCTTA enhancer-binding protein level demonstrated no change compared with LW pigs. Hormone sensitive lipase, adipose tissue triglyceride lipase mRNA expression and the lipase activity were significantly lower (P < 0.05) in EHL. Uncoupling protein-2 protein content was significantly lower (P < 0.01) in EHL than that in LW pigs. We first cloned the nucleotide sequence of Zinc-α2-glycoprotein (ZAG) with 1090 bp and found that both ZAG mRNA expression and protein level in EHL pigs was significantly lower (P < 0.01) than that of LW pigs. β3 adrenergic receptor mRNA expression in EHL pigs was significantly higher (P < 0.01) than that of LW pigs, though tumour necrosis factor α gene expression demonstrated no significant difference. Therefore, the significant breed lipid metabolism difference in subcutaneous fat exists at an early postnatal age between EHL and LW pigs, and this difference may originate from two causes including the increased lipid synthesis and reduced lipid mobilization in EHL pigs compared with LW pigs.
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Ashby J, Pan S, Zhong W. Size and surface functionalization of iron oxide nanoparticles influence the composition and dynamic nature of their protein corona. ACS APPLIED MATERIALS & INTERFACES 2014; 6:15412-9. [PMID: 25144382 PMCID: PMC4160264 DOI: 10.1021/am503909q] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Nanoparticles (NPs) adsorb proteins when in the biological matrix, and the resulted protein corona could affect NP-cell interactions. The corona has a dynamic nature with the adsorbed proteins constantly exchanging with the free proteins in the matrix at various rates. The rapidly exchanging proteins compose the soft corona, which responds more dynamically to environment changes than the hard corona established by the ones with slow exchange rates. In the present study, the corona formed on the superparamagnetic iron oxide NPs (SPIONs) in human serum was studied by flow field-flow fractionation and ultracentrifugation, which rapidly differentiated the corona proteins based on their exchange rates. By varying the surface hydrophobicity of the SPIONs with a core size around 10 nm, we found out that, the more hydrophobic surface ligand attracted proteins with higher surface hydrophobicity and formed a more dynamic corona with a larger portion of the involved proteins with fast exchange rates. Increasing the core diameter of the SPIONs but keeping the surface ligand the same could also result in a more dynamic corona. A brief investigation of the effect on the cellular uptake of SPIONs using one selected corona protein, transferrin, was conducted. The result showed that, only the stably bound transferrin could significantly enhance cellular uptake, while transferrin bound in a dynamic nature had negligible impact. Our study has led to a better understanding of the relationship between the particle properties and the dynamic nature of the corona, which can help with design of nanomaterials with higher biocompatibility and higher efficacy in biosystems for biomedical applications.
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Walker D, Pan S, Modir S, Rickard T. Sleep Enhancement of Texture Discrimination Performance is Dependent on Training Paradigm. J Vis 2014. [DOI: 10.1167/14.10.664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Li N, Pan S, Zhu H, Mu H, Liu W, Hua J. BMP4 promotes SSEA-1(+) hUC-MSC differentiation into male germ-like cells in vitro. Cell Prolif 2014; 47:299-309. [PMID: 24923741 DOI: 10.1111/cpr.12115] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 03/20/2014] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVES Recent studies have demonstrated that primordial germ cells (PGC) can be differentiated from human umbilical cord mesenchymal stem cells (hUC-MSCs), and embryonic stem cells (ESCs) in vitro. Nevertheless, efficiencies were low and unstable. Here, whether hUC-MSCs can be induced to differentiate into germ-like cells with the aid of bone morphogenetic protein (BMP4) was investigated. MATERIALS AND METHODS Human umbilical cord mesenchymal stem cells were freshly isolated and cultured with BMP4. SSEA-1(+/-) cells were purified using magnetic-activated cell sorting (MACS) from the hUC-MSCs, and further induced with BMP4. Quantitative real-time PCR (qRT-PCR) and immunofluorescence analysis were used to determine PGC and germ-like cell-specific markers. RESULTS Human umbilical cord mesenchymal stem cells differentiated into SSEA-1(+) spherical PGC-like cells efficiently with 12.5 ng/ml BMP4. qRT-PCR and immunofluorescence analysis demonstrated that SSEA-1(+) cells expressed higher levels of PGC-specific markers than SSEA-1(-) cells. Furthermore, SSEA-1(+) cells were induced with BMP4 to differentiate into STRA8, SCP3, DMRT1 and PLZF-positive male germ-like cells, and some sperm-like cells were obtained by 7-14 days after induction. CONCLUSION These results suggest that SSEA-1(+) hUC-MSCs can differentiate into male germ-like cells in the presence of BMP4. This study provides an efficient protocol to study germ-cell development using hUC-MSCs.
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Wang F, Gao F, Pan S, Zhao S, Xue Y. Luteolin induces apoptosis, G0/G1 cell cycle growth arrest and mitochondrial membrane potential loss in neuroblastoma brain tumor cells. Drug Res (Stuttg) 2014; 65:91-5. [PMID: 24831243 DOI: 10.1055/s-0034-1372648] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The objective of the present research work was to evaluate the anticancer properties of luteolin against SH-SY5Y neuroblastoma tumor cell line. Cell viability was evaluated by MTT assay after luteolin treatment. Lactate dehydrogenase assay (LDH) was used to evaluate the extent of cell death induced by luteolin. Flow-cytometry was used to examine the effect of luteolin on cell cycle progression and mitochondrial membrane potential (ΛΨm) in SH-SY5Y cells. Phase-contrast microscopy detected the morphological changes in SH-SY5Y cells after luteolin treatment. Our results demonstrated that luteolin induced dose-dependent as well as time-dependent growth inhibition of SH-SY5Y cells with IC50 value of 27.1 µM after 12 h of incubation. Further, luteolin induced significant release of LDH from SH-SY5Y cell cultures following luteolin treatment significantly at 25 and 50 µM doses which corresponds to significant cell death. Phase-contrast microscopy revealed characteristic morphological features of apoptosis induced by luteolin. Flow-cytometry revealed that luteolin induced G0/G1 cell cycle growth arrest in SH-SY5Y cells. Luteolin also induced a progressive and dose-dependent reduction in the mitochondrial membrane potential. In conclusion, our results revealed that luteolin significantly induces growth inhibition of SH-SY5Y tumor cells by inducing apoptosis accompanied with G0/G1 cell cycle growth arrest and concomitant loss in mitochondrial membrane potential (ΛΨm). As such luteolin can be developed as a potent anticancer agent against brain tumor disorders.
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Shi J, Pagliaccia D, Morgan R, Qiao Y, Pan S, Vidalakis G, Ma W. Novel diagnosis for citrus stubborn disease by detection of a spiroplasma citri-secreted protein. PHYTOPATHOLOGY 2014; 104:188-195. [PMID: 23931112 DOI: 10.1094/phyto-06-13-0176-r] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Citrus stubborn disease (CSD), first identified in California, is a widespread bacterial disease found in most arid citrus-producing regions in the United States and the Mediterranean Region. The disease is caused by Spiroplasma citri, an insect-transmitted and phloem-colonizing bacterium. CSD causes significant tree damage resulting in loss of fruit production and quality. Detection of CSD is challenging due to low and fluctuating titer and sporadic distribution of the pathogen in infected trees. In this study, we report the development of a novel diagnostic method for CSD using an S. citri-secreted protein as the detection marker. Microbial pathogens secrete a variety of proteins during infection that can potentially disperse systemically in infected plants with the vascular flow. Therefore, their distribution may not be restricted to the pathogen infection sites and could be used as a biological marker for infection. Using mass spectrometry analysis, we identified a unique secreted protein from S. citri that is highly expressed in the presence of citrus phloem extract. ScCCPP1, an antibody generated against this protein, was able to distinguish S. citri-infected citrus and periwinkle from healthy plants. In addition, the antiserum could be used to detect CSD using a simple direct tissue print assay without the need for sample processing or specialized lab equipment and may be suitable for field surveys. This study provides proof of a novel concept of using pathogen-secreted protein as a marker for diagnosis of a citrus bacterial disease and can probably be applied to other plant diseases.
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Pan S, Carter CJ, Raikhel NV. Understanding protein trafficking in plant cells through proteomics. Expert Rev Proteomics 2014; 2:781-92. [PMID: 16209656 DOI: 10.1586/14789450.2.5.781] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The functions of approximately one-third of the proteins encoded by the Arabidopsis thaliana genome are completely unknown. Moreover, many annotations of the remainder of the genome supply tentative functions, at best. Knowing the ultimate localization of these proteins, as well as the pathways used for getting there, may provide clues as to their functions. The putative localization of most proteins currently relies on in silico-based bioinformatics approaches, which, unfortunately, often result in erroneous predictions. Emerging proteomics techniques coupled with other systems biology approaches now provide researchers with a plethora of methods for elucidating the final location of these proteins on a large scale, as well as the ability to dissect protein-sorting pathways in plants.
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Ridlon L, Škodová I, Pan S, Lukeš J, Maslov DA. The importance of the 45 S ribosomal small subunit-related complex for mitochondrial translation in Trypanosoma brucei. J Biol Chem 2013; 288:32963-78. [PMID: 24089529 DOI: 10.1074/jbc.m113.501874] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The mitochondrial 45 S SSU* complex in Trypanosoma brucei contains the 9 S SSU ribosomal RNA, a set of SSU ribosomal proteins, several pentatricopeptide repeat (PPR) proteins, and proteins not typically found in ribosomes, including rhodanese domain protein (Rhod) and a 200-kDa coiled-coil protein. To investigate the function of this complex, PPR29, Rhod, 200-kDa protein, and mitochondrial ribosomal protein S17 were knocked down by RNAi in procyclic T. brucei. A growth retardation phenotype, a reduction in the amount of the 45 S SSU* complexes, and the preferential inhibition of synthesis of the cytochrome c oxidase subunit I over apocytochrome b were observed as early as day 2 postinduction of RNAi. On the contrary, the down-regulation of mitochondrial ribosomal protein L3 drastically reduced the amount of the large subunit and indiscriminately inhibited mitochondrial translation. The relative amounts of translation-competent, long poly(AU)-tailed cytochrome c oxidase subunit I and edited apocytochrome b mRNAs were selectively reduced by ablation of the 45 S SSU* complex. The formation of the 80 S translation complexes, identified by association of the long-tailed mRNAs with the mitoribosomes, was also disrupted. On the other hand, the relative amount of long-tailed edited RPS12 mRNA was not substantially affected, and there was no noticeable effect on the RPS12 translation complexes. In bloodstream trypanosomes, the amount of the 45 S complexes was drastically reduced compared with procyclics. We propose that the 45 S SSU* complex represents a factor required for normal mitochondrial translation that may have selective effects on different mRNAs.
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Ashby J, Schachermeyer S, Pan S, Zhong W. Dissociation-based screening of nanoparticle-protein interaction via flow field-flow fractionation. Anal Chem 2013; 85:7494-501. [PMID: 23859073 PMCID: PMC3815437 DOI: 10.1021/ac401485j] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A protein corona will be formed on nanoparticles (NPs) entering a biological matrix, which can influence particles' subsequent behaviors inside the biological systems. For proteins bound stably to the NPs, they can exhibit different association/dissociation rates. The binding kinetics could affect interaction of the NPs with cell surface receptors and possibly contribute to the outcomes of NPs uptake. In the present study, a method to differentiate the corona proteins based on their relative dissociation rates from the NPs was developed, employing flow field-flow fraction (F4) in combination with centrifugation. The proteins bound to the superparamagnetic iron oxide NPs (SPION) present in an IgG/albumin depleted serum were isolated via collection of the SPIONs by either F4 or centrifugation. They were subsequently analyzed by LC-MS/MS and identified. Because the SPION-protein complexes injected to F4 dissociated continuously under the nonequilibrium separation condition, only the proteins with slow enough dissociation rates would be collected with the NPs in the eluent of F4. However, in centrifugation, proteins with good affinity to the SPIONs were collected regardless of the dissociation rates of the complexes. In both cases, the nonbinding ones were washed off. Capillary electrophoresis and circular dichroism were employed to verify the binding situations of a few SPION-protein interactions, confirming the effectiveness of our method. Our results support that our method can screen for proteins binding to NPs with fast on-and-off rates, which should be the ones quickly exchanging with the free matrix proteins when the NPs are exposed to a new biological media. Thus, our method will be useful for investigation of the temporal profile of protein corona and its evolution in biological matrices as well as for high-throughput analysis of the dynamic feature of protein corona related to particle properties.
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Pan S, Zheng Y, Zhao R, Yang X. miRNA-374 regulates dexamethasone-induced differentiation of primary cultures of porcine adipocytes. Horm Metab Res 2013; 45:518-25. [PMID: 23468252 DOI: 10.1055/s-0033-1334896] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
UNLABELLED To investigate the effect of glucocorticoid on adipocytes metabolism and miRNAs that may be involved in adipocyte differentiation, primary porcine preadipocytes were treated with 10-6 M dexamethasone and RU486 (a glucocorticoid receptor antagonist) for 48 h. PPAR-γ (peroxisome proliferators-activated receptor-γ), and C/EBP-β (CCTTA enhancer binding protein-β) gene and protein expression were measured. The expressions of miRNAs predicted to directly target C/EBP-β were determined, and the functions of the potential miRNAs were verified. The results showed that the triglyceride content in cultured adipocytes increased significantly after 10-6 M dexamethasone treatment for 48 h, whereas the cell viability did not differ among the four groups ( CONTROL 10-6 M dexamethasone; 10-6 M RU486: 10-6 M dexamethasone+10-6 M RU486) (p>0.05). Cells treated with dexamethasone for 48 h significantly upregulated perilipin and PPAR-γ gene expression, and PPAR-γ protein expression was also significantly increased. However, C/EBP-β mRNA and protein expression levels were significantly decreased. Both miR-374a and miR-374b, targeting the C/EBP-β 3'-UTR (3'-untranslated region), were significantly increased. Dual luciferase activity assay results indicated that miR-374a/b was directly recognised and bound to the 3'-UTR of C/EBP-β and thereby suppressed C/EBP-β gene expression. The present study showed that 10-6 M dexamethasone promotes lipid accumulation in primary cultures of porcine preadipocytes. PPAR-γ and C/EBP-β protein abundance showed differences after 48 h dexamethasone treatment; miR-374a/b may be involved in regulating of C/EBP-β expression. These results provide new targets for further regulation of porcine lipid metabolism.
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