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ABSTRACT: Diabetes mellitus is a complex metabolic disorder characterized by chronic hyperglycemia due to absolute or relative lack of insulin. Though great efforts have been made to investigate the pathogenesis of diabetes, the underlying mechanism behind the development of diabetes and its complications remains unexplored. Cumulative evidence has linked mitochondrial modification to the pathogenesis of diabetes and its complications and they are also observed in various tissues affected by diabetes. Proteomics is an attractive tool for the study of diabetes since it allows researchers to compare normal and diabetic samples by identifying and quantifying the differentially expressed proteins in tissues, cells or organelles. Great progress has already been made in mitochondrial proteomics to elucidate the role of mitochondria in the pathogenesis of diabetes and its complications. Further studies on the changes of mitochondrial protein specifically post-translational modifications during the diabetic state using proteomic tools, would provide more information to better understand diabetes.
Protein & Cell 06/2012; 3(9):648-60.
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Peng Zhang,
Huimin Na,
Zhenglong Liu,
Shuyan Zhang,
Peng Xue,
Yong Chen,
Jing Pu,
Gong Peng,
Xun Huang, Fuquan Yang,
Zhensheng Xie,
Tao Xu,
Pingyong Xu,
Guangshuo Ou,
Shaobing O Zhang,
Pingsheng Liu
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ABSTRACT: Lipid droplets (LDs) are a neutral lipid storage organelle that is conserved across almost all species. Many metabolic syndromes are directly linked to the over-storage of neutral lipids in LDs. The study of LDs in Caenorhabditis elegans (C. elegans) has been difficult because of the lack of specific LD marker proteins. Here we report the purification and proteomic analysis of C. elegans lipid droplets for the first time. We identified 306 proteins, 63% of these proteins were previously known to be LD-proteins, suggesting a similarity between mammalian and C. elegans LDs. Using morphological and biochemical analyses, we show that short-chain dehydrogenase, DHS-3 is almost exclusively localized on C. elegans LDs, indicating that it can be used as a LD marker protein in C. elegans. These results will facilitate further mechanistic studies of LDs in this powerful genetic system, C. elegans.
Molecular & Cellular Proteomics 04/2012; 11(8):317-28. · 7.40 Impact Factor
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Lei Liu,
Du Feng,
Guo Chen,
Ming Chen,
Qiaoxia Zheng,
Pingping Song,
Qi Ma,
Chongzhuo Zhu,
Rui Wang,
Wanjun Qi, [......],
Peng Xue,
Baowei Li,
Xiaohui Wang,
Haijing Jin,
Jun Wang, Fuquan Yang,
Pingsheng Liu,
Yushan Zhu,
Senfang Sui,
Quan Chen
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ABSTRACT: Accumulating evidence has shown that dysfunctional mitochondria can be selectively removed by mitophagy. Dysregulation of mitophagy is implicated in the development of neurodegenerative disease and metabolic disorders. How individual mitochondria are recognized for removal and how this process is regulated remain poorly understood. Here we report that FUNDC1, an integral mitochondrial outer-membrane protein, is a receptor for hypoxia-induced mitophagy. FUNDC1 interacted with LC3 through its typical LC3-binding motif Y(18)xxL(21), and mutation of the LC3-interaction region impaired its interaction with LC3 and the subsequent induction of mitophagy. Knockdown of endogenous FUNDC1 significantly prevented hypoxia-induced mitophagy, which could be reversed by the expression of wild-type FUNDC1, but not LC3-interaction-deficient FUNDC1 mutants. Mechanistic studies further revealed that hypoxia induced dephosphorylation of FUNDC1 and enhanced its interaction with LC3 for selective mitophagy. Our findings thus offer insights into mitochondrial quality control in mammalian cells.
Nature Cell Biology 02/2012; 14(2):177-85. · 19.49 Impact Factor
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Jing Li,
Zhensheng Xie,
Linan Shi,
Zhiqiang Zhao,
Junjie Hou,
Xiulan Chen,
Ziyou Cui,
Peng Xue,
Tanxi Cai,
Peng Wu,
Sutang Guo, Fuquan Yang
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ABSTRACT: Surface-enhanced laser desorption/ionization time of flight mass spectrometry (SELDI-TOF-MS) is a powerful tool for screening potential biomarkers of various pathological conditions. However, low resolution and mass accuracy of SELDI-TOF-MS remain a major obstacle for determination of biological identities of potential protein biomarkers. We report here a refined workflow that combines ZipTip desalting, acetonitrile precipitation, high-performance liquid chromatography (HPLC) separation and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) analysis for the profiling, purification and identification of the targeted serum proteins found by SELDI-TOF-MS. By using this workflow, we purified ten targeted proteins from the sera of patients with various types of advanced stage (stage III-IV) cancers. These proteins were identified as isoforms of the human serum amyloid protein A (SAA) family with or without truncations at their N-terminals. This was confirmed by Western blot analysis. Different SAA expression patterns were observed by MALDI-TOF-MS profiling. SAA has long been reported as a biomarker for various cancer types such as lung cancer, ovarian cancer, and breast cancer. However, in this study we found increased SAA expression in the sera of advanced-stage cancer patients with different cancer types. Our results suggest that maybe SAA should not be used alone as a biomarker for any specific cancer type.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 01/2012; 889-890:3-9. · 2.78 Impact Factor
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Yunfeng Ding,
Li Yang,
Shuyan Zhang,
Yang Wang,
Yalan Du,
Jing Pu,
Gong Peng,
Yong Chen,
Huina Zhang,
Jinhai Yu,
Haiying Hang,
Peng Wu, Fuquan Yang,
Hongyuan Yang,
Alexander Steinbüchel,
Pingsheng Liu
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ABSTRACT: Storage of cellular triacylglycerols (TAGs) in lipid droplets (LDs) has been linked to the progression of many metabolic diseases in humans, and to the development of biofuels from plants and microorganisms. However, the biogenesis and dynamics of LDs are poorly understood. Compared with other organisms, bacteria seem to be a better model system for studying LD biology, because they are relatively simple and are highly efficient in converting biomass to TAG. We obtained highly purified LDs from Rhodococcus sp. RHA1, a bacterium that can produce TAG from many carbon sources, and then comprehensively characterized the LD proteome. Of the 228 LD-associated proteins identified, two major proteins, ro02104 and PspA, constituted about 15% of the total LD protein. The structure predicted for ro02104 resembles that of apolipoproteins, the structural proteins of plasma lipoproteins in mammals. Deletion of ro02104 resulted in the formation of supersized LDs, indicating that ro02104 plays a critical role in cellular LD dynamics. The putative α helix of the ro02104 LD-targeting domain (amino acids 83-146) is also similar to that of apolipoproteins. We report the identification of 228 proteins in the proteome of prokaryotic LDs, identify a putative structural protein of this organelle, and suggest that apolipoproteins may have an evolutionarily conserved role in the storage and trafficking of neutral lipids.
The Journal of Lipid Research 12/2011; 53(3):399-411. · 5.56 Impact Factor
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ABSTRACT: Wilms tumor is the most common pediatric tumor of the kidney. Previous studies have identified several serum biomarkers for Wilms tumor; however, they lack sufficient specificity and may not adequately distinguish Wilms tumor from confounding conditions. To date, no specific protein biomarker has been confirmed for this pediatric tumor. To identify novel serum biomarkers for Wilms tumor, we used proteomic technologies to perform protein profiling of serum samples from pre-surgery and post-surgery patients with Wilms tumor and healthy controls. Some common systemic inflammatory factors were included to control for systemic inflammation. By comparing protein peaks among the three groups of sera, we identified two peaks (11,526 and 4,756 Da) showing significant differential expression not only between pre-surgery and control sera but also between pre-surgery and post-surgery sera. These two peaks were identified as serum amyloid A1 (SAA1) and apolipoprotein C-III (APO C-III). Western blot analysis confirmed that both proteins were expressed at higher levels in pre-surgery sera than in post-surgery and control sera. Using the method of leave-1-out for cross detection, we demonstrate that detection of these two candidate biomarkers had high sensitivity and specificity in discriminating pre-surgery sera from post-surgery and normal control sera. Taken together, these findings suggest that SAA1 and APO C-III are two potential biomarkers for Wilms tumor.
Molecular Biology Reports 12/2011; 39(5):5095-104. · 2.93 Impact Factor
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Yang Lu,
Xiaoluan Liu,
Suozhu Shi,
Huabin Su,
Xueyuan Bai,
Guangyan Cai, Fuquan Yang,
Zhensheng Xie,
Yunping Zhu,
Yanqiong Zhang,
Shujia Zhang,
Xiaofan Li,
Shan Wang,
Di Wu,
Li Zhang,
Jie Wu,
Yuansheng Xie,
Xiangmei Chen
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ABSTRACT: Anti-Thy1 nephritis is a well-established experimental mesangial proliferative nephritis model. Exploring the molecular mechanisms of pathophysiology in anti-Thy1 nephritis may elucidate the pathogeneses of mesangial proliferation. We examined the roles and acting mechanisms of differentially expressed proteins (DEPs) by bioinformatics analysis of glomeruli proteomic profiles during the course of anti-Thy1 nephritis. In total, 108 DEPs were found by two-dimensional fluorescence difference gel electrophoresis (2D-DIGE), and 40 DEPs were identified by matrix-assisted laser desorption ionization/time of flight and liquid chromatography-MS. DEPs were classified into five clusters (Clusters 1-5), according to their expression trends using Cluster 3.0 software, involved in regulating biological processes such as the stress response, cell proliferation, apoptosis, energy metabolism, transport, and the actin cytoskeleton. The expression patterns of ten DEPs, distributed across five clusters, including AKR1A1, AGAT, ATP6V1B2, HIBADH, MDH1, MPST, NIT2, PRDX6, PSMB7, and TPI1, were validated by Western blotting. Based on Western blotting and immunohistochemistry, we also found that the DEP FHL2, which was primarily expressed in the mesangial region, was down-regulated on days 3 and 5, and up-regulated on day 10. In vitro, we found that FHL2 overexpression induced mesangial cell proliferation by increasing the number of S-phase cells and decreasing G2/M-phase cells, whereas inhibiting FHL2 had the opposite effect. This study explored novel DEPs and their expression patterns during anti-Thy1 nephritis, and elucidated FHL2's effect on mesangial cell proliferation. These results will contribute to our understanding of the pathogenesis of mesangial proliferation.
Molecular & Cellular Proteomics 12/2011; 11(4):M111.008755. · 7.40 Impact Factor
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ABSTRACT: Pesticides have adverse health effects and can be transported over long distances to contaminate sensitive ecosystems. To address problems caused by environmental pesticides we developed a multimedia multi-pollutant modeling system, and here we present an evaluation of the model by comparing modeled results against measurements. The modeled toxaphene air concentrations for two sites, in Louisiana (LA) and Michigan (MI), are in good agreement with measurements (average concentrations agree to within a factor of 2). Because the residue inventory showed no soil residues at these two sites, resulting in no emissions, the concentrations must be caused by transport; the good agreement between the modeled and measured concentrations suggests that the model simulates atmospheric transport accurately. Compared to the LA and MI sites, the measured air concentrations at two other sites having toxaphene soil residues leading to emissions, in Indiana and Arkansas, showed more pronounced seasonal variability (higher in warmer months); this pattern was also captured by the model. The model-predicted toxaphene concentration fraction on particles (0.5–5%) agrees well with measurement-based estimates (3% or 6%). There is also good agreement between modeled and measured dry (1:1) and wet (within a factor of less than 2) depositions in Lake Ontario. Additionally this study identified erroneous soil residue data around a site in Texas in a published US toxaphene residue inventory, which led to very low modeled air concentrations at this site. Except for the erroneous soil residue data around this site, the good agreement between the modeled and observed results implies that both the US and Mexican toxaphene soil residue inventories are reasonably good. This agreement also suggests that the modeling system is capable of simulating the important physical and chemical processes in the multimedia compartments.
Environmental Research Letters 09/2011; 6(3):034030. · 3.63 Impact Factor
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ABSTRACT: We have combined the US EPA MM5/MCIP/SMOKE/CMAQ modeling system with a dynamic soil model, the pesticide emission model (PEM), to create a multimedia chemical transport model capable of describing the important physical and chemical processes involving pesticides in the soil, in the atmosphere, and on the surface of vegetation. These processes include: agricultural practices (e.g. soil tilling and pesticide application mode); advection and diffusion of pesticides, moisture, and heat in the soil; partitioning of pesticides between soil organic carbon and interstitial water and air; emissions from the soil to the atmosphere; gas–particle partitioning and transport in the atmosphere; and atmospheric chemistry and dry and wet deposition of pesticides to terrestrial and water surfaces. The modeling system was tested by simulating toxaphene in a domain that covers most of North America for the period from 1 January 2000 to 31 December 2000. The results show obvious transport of the pesticide from the heavily contaminated soils in the southern United States and Mexico to water bodies including the Atlantic Ocean, the Gulf of Mexico and the Great Lakes, leading to significant dry and wet deposition into these ecosystems. The spatial distributions of dry and wet depositions differ because of their different physical mechanisms; the former follows the distribution of air concentrations whereas the latter is more biased to the North East due to the effect of precipitation.
Environmental Research Letters 09/2011; 6(3):034029. · 3.63 Impact Factor
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Huina Zhang,
Yang Wang,
Jing Li,
Jinhai Yu,
Jing Pu,
Linghai Li,
Hongchao Zhang,
Shuyan Zhang,
Gong Peng, Fuquan Yang,
Pingsheng Liu
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ABSTRACT: The lipid droplet (LD) is a universal organelle governing the storage and turnover of neutral lipids. Mounting evidence indicates that elevated intramuscular triglyceride (IMTG) in skeletal muscle LDs is closely associated with insulin resistance and Type 2 Diabetes Mellitus (T2DM). Therefore, the identification of the skeletal muscle LD proteome will provide some clues to dissect the mechanism connecting IMTG with T2DM. In the present work, we identified 324 LD-associated proteins in mouse skeletal muscle LDs through mass spectrometry analysis. Besides lipid metabolism and membrane traffic proteins, a remarkable number of mitochondrial proteins were observed in the skeletal muscle LD proteome. Furthermore, imaging by fluorescence microscopy and transmission electronic microscopy (TEM) directly demonstrated that mitochondria closely adhere to LDs in vivo. Moreover, our results revealed for the first time that apolipoprotein A-I (apo A-I), the principal apolipoprotein of high density lipoprotein (HDL) particles, was also localized on skeletal muscle LDs. Further studies verified that apo A-I was expressed endogenously by skeletal muscle cells. In conclusion, we report the protein composition and characterization of skeletal muscle LDs and describe a novel LD-associated protein, apo A-I.
Journal of Proteome Research 08/2011; 10(10):4757-68. · 5.11 Impact Factor
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ABSTRACT: Xbp1 has been shown to regulate the cell cycle as a transcriptional repressor in budding yeast Saccharomyces cerevisiae. In this study, we demonstrated that Xbp1 regulates DNA double-strand break (DSB) repair in S. cerevisiae. Xbp1 physically and genetically interacts with the histone deacetylase Rpd3 complex. Chromatin immunoprecipitation revealed that Xbp1 is required for efficient deacetylation of histone H4 flanking DSBs by the Rpd3 complex. Deletion of XBP1 leads to the delayed deacetylation of histone H4, which is coupled with increased nucleosome displacement, increased DNA end resection and decreased non-homologous end-joining (NHEJ). In response to DNA damage, Xbp1 is upregulated in a Mec1-Rad9-Rad53 checkpoint pathway-dependent manner and undergoes dephosphorylation. Cdk1, a central regulator of S. cerevisiae cell cycle, is responsible for Xbp1 phosphorylation at residues Ser146, Ser271 and Ser551. Substitution of these serine residues with alanine not only increases the association of Xbp1 with the Rpd3 complex and its recruitment to a DSB, but also promotes DSB repair. Together, our findings reveal a role for Xbp1 in DSB repair via NHEJ through regulation of histone H4 acetylation and nucleosome displacement in a positive feedback manner.
Cell Research 04/2011; 21(11):1619-33. · 8.19 Impact Factor
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ABSTRACT: High-speed counter-current chromatography (HSCCC) was successfully applied for the preparative separation and purification of alkaloids from Corydalis bungeana Turcz. (Kudiding in Chinese) for the first time. After the measurement of partition coefficient of seven target alkaloids in the nine two-phase solvent systems composed of CHCl(3)-MeOH-(0.1 M; 0.2 M; 0.3 M) HCl (4:1.5:2; 4:2:2; 4:3:2, v/v), CHCl(3)-MeOH-0.2 M HCl (4:2:2, v/v) and CHCl(3)-MeOH-0.3 M HCl (4:3:2, v/v) were finally selected for the HSCCC separation using the first upper phase as the stationary phase and the stepwise elution of the two lower mobile phases. Consequently, sanguinarine (10 mg), corynoline (25 mg), protopine (20 mg), corynoloxine (18 mg), and 12-hydroxycorynoline (8 mg) were obtained from 200 mg of crude alkaloid extracts with purities of 94-99% as determined by HPLC. Their chemical structures were characterized on the basis of (1)H-NMR, (13)C-NMR, and LC-ESI-Q-TOF-MS/MS analyses.
Journal of Separation Science 03/2011; 34(9):987-94. · 2.73 Impact Factor
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Jianying Xiao,
Chao Liu,
Junjie Hou,
Cheng Cui,
Didi Wu,
Huiyu Fan,
Xiaohan Sun,
Jun Meng, Fuquan Yang,
Enhua Wang,
Bingzhi Yu
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ABSTRACT: It is well documented that protein kinase A (PKA) acts as a negative regulator of M phase promoting factor (MPF) by phosphorylating cell division cycle 25 homolog B (Cdc25B) in mammals. However, the molecular mechanism remains unclear. In this study, we identified PKA phosphorylation sites in vitro by LC-MS/MS analysis, including Ser(149), Ser(229), and Ser(321) of Cdc25B, and explored the role of Ser(149) in G(2)/M transition of fertilized mouse eggs. The results showed that the overexpressed Cdc25B-S149A mutant initiated efficient MPF activation by direct dephosphorylation of Cdc2-Tyr(15), resulting in triggering mitosis prior to Cdc25B-WT. Conversely, overexpression of the phosphomimic Cdc25B-S149D mutant showed no significant difference in comparison with the control groups. Furthermore, we found that Cdc25B-Ser(149) was phosphorylated at G(1) and S phases, whereas dephosphorylated at G(2) and M phases, and the phosphorylation of Cdc25B-Ser(149) was modulated by PKA in vivo. In addition, we examined endogenous and exogenous Cdc25B, which were expressed mostly in the cytoplasm at the G(1) and S phases and translocated to the nucleus at the G(2) phase. Collectively, our findings provide evidence that Ser(149) may be another potential PKA phosphorylation target of Cdc25B in G(2)/M transition of fertilized mouse eggs and Cdc25B as a direct downstream substrate of PKA in mammals, which plays important roles in the regulation of early development of mouse embryos.
Journal of Biological Chemistry 01/2011; 286(12):10356-66. · 4.77 Impact Factor
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ABSTRACT: Research has shown that the palmitoyl group of α-tubulin mediates the hydrophobic interaction between microtubules and intracellular membranes and that palmitoylated tubulin plays a role in signal transduction. There are 20 cysteine residues per α/β tubulin heterodimer. C376 of α-tubulin was reported to be predominantly palmitoylated and C20, C213 and C305 of α-tubulin were palmitoylated at lower levels. The previous method used for the analysis of the palmitoylation sites on α-tubulin was based on ³H-labeling, enzymolysis, purification and sequencing. This approach, although efficient, is laborious. Mass spectrometry (MS), especially tandem MS, has been shown to be a successful method for identification of various post-translational modifications of proteins. We report here a convenient MS-based method to comprehensively analyze the palmitoylation sites of the α/β tubulin heterodimer. Acyl-biotinyl exchange chemistry and streptavidin agarose affinity purification were applied to enrich palmitoylated peptides from tubulin. After nano-LC-MS/MS analysis, database searching and manual analysis of the spectra revealed that 11 cysteine residues of the α/β tubulin heterodimer were palmitoylated.
The Protein Journal 10/2010; 29(8):531-7. · 1.04 Impact Factor
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ABSTRACT: Mitochondria are organelles that are essential for cell life and death. A huge range of pathologies, including neurodegenerative diseases, cancer, diabetes and aging, have been reported to be associated with mitochondrial dysfunction. Therefore, identification of mitochondrial proteins that are differentially expressed in these pathologies will help to further our understanding of these diseases. In recent years, great achievements have been made in mammalian mitochondrial proteomics. Here we provide an overview of the current state of knowledge with respect to the whole mitochondrial proteome, the mitochondrial subproteome, mitochondrial complexes and mitochondrial post-translational modifications. Applications of comparative mitochondrial proteomics to various pathologies that have provided clues for understanding the relationship between mitochondrial dysfunction and pathogenesis are described. We conclude that mitochondrial proteomics can be used not only to map all the components of mitochondria, but can also provide information for discovering therapeutic targets for mitochondria-related diseases.
Expert Review of Proteomics 06/2010; 7(3):333-45. · 3.68 Impact Factor
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ABSTRACT: Mitochondria have important roles in cellular physiological functions and various diseases. In pancreatic β cells, mitochondria play a central role in glucose-stimulated insulin secretion (GSIS). To reveal the potential functions of mitochondria in the GSIS process in β cells, shotgun proteomics was applied to profiling mitochondrial proteins and their potential phosphorylation sites in rat INS-1 cells. More than 800 proteins were assigned to mitochondria. In addition, 84 different mitochondrial phosphoproteins were identified, and 52 upstream kinases of mitochondrial phosphoproteins were predicted using bioinformatics tools. Regulation networks of mitochondrial phosphoproteins were constructed by integrating mitochondrial protein interaction networks and mitochondrial phosphorylation signaling, providing a preliminary survey of how phosphorylation signaling regulates mitochondrial function in β cells. We present integrated resources including the protein composition and signaling pathways of mitochondria which can be used to understand the role of mitochondria in GSIS.Keywords: mitochondria; β cells; GSIS; proteome; mitochondrial protein phosphorylation; signaling network
04/2010;
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ABSTRACT: Mitochondria have important roles in cellular physiological functions and various diseases. In pancreatic beta cells, mitochondria play a central role in glucose-stimulated insulin secretion (GSIS). To reveal the potential functions of mitochondria in the GSIS process in beta cells, shotgun proteomics was applied to profiling mitochondrial proteins and their potential phosphorylation sites in rat INS-1 cells. More than 800 proteins were assigned to mitochondria. In addition, 84 different mitochondrial phosphoproteins were identified, and 52 upstream kinases of mitochondrial phosphoproteins were predicted using bioinformatics tools. Regulation networks of mitochondrial phosphoproteins were constructed by integrating mitochondrial protein interaction networks and mitochondrial phosphorylation signaling, providing a preliminary survey of how phosphorylation signaling regulates mitochondrial function in beta cells. We present integrated resources including the protein composition and signaling pathways of mitochondria which can be used to understand the role of mitochondria in GSIS.
Journal of Proteome Research 04/2010; 9(6):2898-908. · 5.11 Impact Factor
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ABSTRACT: The rat L6 myotubes is an important in vitro model system for studying signaling pathways in skeletal muscle. Exploring phosphorylation events involved in the skeletal muscle is very significant for elucidating the kinase-substrate relationship, understanding regulatory mechanisms involved in signaling pathways and providing insights into numerous cell processes. Here, we used mass spectrometry-based proteomics to conduct global phosphoproteome profiling of rat L6 myotubes. Using an efficient phosphoproteomic strategy including prefractionation of tryptic peptide mixtures with self-packed RP C18 columns, phosphopeptide enrichment with TiO2, and 2D-LC (SCX/RP)-MS/MS analysis, a total of 2230 unique phosphopeptides from 1195 proteins were identified with a false-discovery rate of less than 1.0% using a target/decoy database searching strategy. After determining the degree of certainty of the phosphorylation site location (Ascore value ≥19), 11 Ser motifs and one Thr motif were derived from our data set using the Motif-X algorithm. Several potential signaling pathways were found in our myotubes phosphoproteome, such as the MAPK signaling pathway and the IGF-1/Insulin signaling pathway.Keywords: Phosphoproteome; rat L6 myotubes; RP-C18 Prefractionation; TiO2; 2D-LC-MS/MS; signaling pathway
01/2010;
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ABSTRACT: At present, the FAQ (frequently-asked question) answering system cannot understand the user's questions at the concept level, so its efficiency needs to be improved. In this paper, a model of FAQ answering system based on concept is proposed. The system model consists of three components, which are concept-based preprocessing, extraction of question-answer pairs, and concept-based matching of sentences. On the one hand, the model proposes an index-based extracting method of question-answering pairs, to combine the extraction with the index mechanism for improving the speed of extraction. On the other hand, the model expands the user's question at the concept level, and proposes a concept based matching method between sentences, to match the user's question with the question-answering pairs. The concept based matching method concerns the synonymous meanings between sentences at the concept level. In addition, the experimental result shows the matching method is an efficient method.
Knowledge Acquisition and Modeling, 2009. KAM '09. Second International Symposium on; 01/2010
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ABSTRACT: Primary open angle glaucoma (POAG) is a leading cause of irreversible blindness on a global level. Researchers have yet to specify the exact mechanisms of POAG; the respective relationships between POAG and elevated intraocular pressure (IOP), as well as optic neuropathy, remain particularly unclear. It is known, however, that the expression profile for some proteins in the aqueous humor (AH) changes in some diseases, and that AH changes play important roles in elevated IOP. To identify the possible roles of these AH proteins in POAG, a proteomic analysis of the AH compositions of POAG patients' eyes was performed and compared with those derived from paired, non-POAG cataract (control) eyes.
We used Bradford's method to determine total protein concentration in AH, and analyzed separation profiles via two-dimensional (2D) gel electrophoresis. We used silver stain to determine gel proteins, and analyzed separation profiles to assess spot density differences between POAG and non-POAG patients. These gel spots were isolated and identified via mass spectrometry. Prostaglandin H2 D-isomerase (PGDS) in AH were analyzed by western Blotting.
There was no significant difference between the total protein concentration in AH of POAG patients and that in AH of non-POAG patients. A total of seven spots were increased in 2D gels from POAG patients. The spots were derived from PGDS, caspase 14 precursor, transthyretin, cystain C, albumin precursor, and tranferrin. And PGDS in AH from patients was more than from controls.
The protein composition in AH was significantly different in POAG patients versus non-POAG patients. The identified proteins could be a potential biomarker for POAG and may play a role in the mechanisms of elevated IOP and optic neuropathy in POAG.
Molecular vision 01/2010; 16:2839-46. · 2.20 Impact Factor
