In eukaryotes protein phosphorytion is a key event. By reversible protein phosphorylation eukaryotes control many cellular processes including signal transduction, gene expression, the cell cycle etc. Phosphoproteomics involves identification of phosphoproteins and phosphopeptides, localization of the exact residues that are phosphorylated and quantitation of phosphorylation. Because protein phosphorylation is a dynamic process, and it is present at low abundance within cells, and the phosphorylated sites on proteins might vary, and mass spectrometry (MS) signals from phosphopeptides are usually suppressed etc., so phosphoprotein analysis have more difficulties than nonphosphoprotein. In this article, we outline several analysis techniques for separation, identification and quantitation of phosphorylated proteins and peptides, and discuss the progress in these techniques. At present, MS is still an essential core identification technology for phosphoproteomic studies, To search better enrichment strategies are the main challenges in this rapidly evolving field. A major goal of quantitative proteomics is precise quantification and identification of proteins in complex mixtures. A common method for quantitative proteome analysis is the stable isotope labeling method. Today there is no single method that supersedes all others techniques for Phosphoproteomic studies. With continued development of sample preparation techniques and instrumentation, it should be possible to perform a global analysis of protein phosphorylation.
Animals ; Humans ; Mass Spectrometry ; Phosphoproteins ; analysis ; Phosphorylation ; Proteomics ; methods

BACKGROUNDThe molecular mechanisms underlying the endometriosis are still not completely understood. In order to test the hypothesis that the approaches in phosphoproteomics might contribute to the identification of key biomarkers to assess disease pathogenesis and drug targets, we carried out a phosphoproteomics analysis of human endometrium.

METHODSA large-scale differential phosphoproteome analysis, using peptide enrichment of titanium dioxide purify and sequential elution from immobilized metal affinity chromatography with linear trap quadrupole-tandem mass spectrometry, was performed in endometrium tissues from 8 women with or without endometriosis.

RESULTSThe phosphorylation profiling of endometrium from endometriosis patients had been obtained, and found that identified 516 proteins were modified at phosphorylation level during endometriosis. Gene ontology annotation analysis showed that these proteins were enriched in cellular processes of binding and catalytic activity. Further pathway analysis showed that ribosome pathway and focal adhesion pathway were the top two pathways, which might be deregulated during the development of endometriosis.

CONCLUSIONSThat large-scale phosphoproteome quantification has been successfully identified in endometrium tissues of women with or without endometriosis will provide new insights to understand the molecular mechanisms of the development of endometriosis.

Adolescent ; Adult ; Chromatography, Affinity ; Endometriosis ; metabolism ; Endometrium ; metabolism ; Female ; Humans ; Phosphoproteins ; analysis ; Phosphorylation ; Proteomics ; methods ; Tandem Mass Spectrometry ; Young Adult

OBJECTIVETo determine AF172993 sequence is either the complete CDS or a transcript variant.

METHODSRT-PCR was used to amplify the CDS sequence of Plunc, which was subsequently cloned into the pEGFP-N1 eukaryotic expression vector. After bi-directional sequence analysis, the sequence obtained was blasted against the AF172993 sequence, nr database and human genome database.

RESULTSIn CDS of the new cloned sequence, the 658 base A in the AF172993 sequence was replaced by C, and the corresponding genetic code was also converted from AAG to CAG, leading to the alteration of the amino acid Gln to Lys. In addition, the base C at the 658 position of the CDS showed perfect match with the base C at 2094188 position in human chromosome 20.

CONCLUSIONThe base A at the 658 position of AF172993 sequence of Plunc is a mutation site, which alters the coding of the amino acid. AF172993 sequence is actually a transcript variant of Plunc, and the annotation to AF172993 in GenBank database is not correct and need to be revised.

Cloning, Molecular ; Databases, Nucleic Acid ; Glycoproteins ; genetics ; Humans ; Mutation, Missense ; Open Reading Frames ; genetics ; Phosphoproteins ; genetics ; Sequence Analysis, DNA

OBJECTIVETo investigate the effect of removing EDTA-soluble phosphate protein in dentin on the later remineralization for the purpose of better understanding of mechanism of dentin phosphate proteins on dentin mineralization.

METHODSTo remove soluble phosphate protein by EDTA dissolution, then the remineralization rate was monitored by a constant composition crystal growth technique. The results were compared with those from the normal dentin and the dentin partially demineralized by acetic acid.

RESULTSFaster remineralization rates were found with dentin demineralized by EDTA (0.5 and 2 h) compared with normal dentin powder, while a slower rate was found with dentin demineralized by acetic acid. The increase of remineralization rate by removing phosphate protein from dentin was 100% more at 200 min after the start of the reaction.

CONCLUSIONEDTA-soluble phosphate protein in dentin has a great potential to inhibit remineralization.

Dental Cementum ; chemistry ; metabolism ; Dentin ; chemistry ; Edetic Acid ; Humans ; Phosphoproteins ; analysis ; physiology ; Tooth Demineralization ; metabolism ; Tooth Remineralization

OBJECTIVETo investigate the host-defense role of short palate, lung, and nasal epithelium clone 1 (SPLUNC1) in Streptococcus pneumoniae (SP) infection and the effect of resveratrol (Res) on SPLUNC1 expression, and to provide new thoughts for the treatment of diseases caused by SP infection.

METHODSAccording to the multiplicity of infection (MOI), BEAS-2B cells with SP infection were divided into control group, MOI20 SP group, and MOI50 SP group. According to the different concentrations of Res, the BEAS-2B cells with MOI20 SP infection pretreated by Res were divided into 12.5Res+SP group, 25Res+SP group, and 50Res+SP group (the final concentrations of Res were 12.5, 25, and 50 μmol/L, respectively). Cell Counting Kit-8 was used to measure cell activity and determine the optimal concentration and action time of SP and Res. In the formal experiment, the cells were divided into control group, Res group, SP group, and Res+SP group. Real-time PCR and ELISA were used to measure the mRNA and protein expression of SPLUNC1.

RESULTSOver the time of SP infection, cell activity tended to decrease. Compared with the control group and the MOI20 SP group, the MOI50 SP group had a reduction in cell activity. Compared with the MOI20 SP group, the 25Res+SP group had increased cell activity and the 50Res+SP group had reduced cell activity (P<0.05). MOI20 SP bacterial suspension and 25 μmol/L Res were used for the formal experiment. Over the time of SP infection, the mRNA expression of SPLUNC1 in BEAS-2B cells firstly increased and then decreased in the SP group and the Res+SP group (P<0.05). Compared with the SP group, the Res+SP group had significant increases in the mRNA and protein expression of SPLUNC1 at all time points (P<0.05). Compared with the control group, the Res group had no significant changes in the mRNA and protein expression of SPLUNC1 (P>0.05).

CONCLUSIONSSP infection can induce SPLUNC1 expression and the host-defense role of SPLUNC1. Res can upregulate SPLUNC1 expression during the development of infection and enhance cell protection in a concentration- and time-dependent manner.

Bronchi ; metabolism ; Cells, Cultured ; Cytoprotection ; Epithelial Cells ; metabolism ; Glycoproteins ; analysis ; genetics ; physiology ; Humans ; Phosphoproteins ; analysis ; genetics ; physiology ; RNA, Messenger ; analysis ; Stilbenes ; pharmacology ; Streptococcus pneumoniae ; pathogenicity

OBJECTIVEThe purpose of this study was to assess weather the immortalized mouse brain endothelial cell line Bend.3 displays the comparative barrier characteristics as the primary brain microvascular endothelial cells (BEMC).

METHODSImmortalized mouse brain endothelial cell line, Bend.3 cells were cultured in transwell inserts and their restrictive characteristics were assessed by transendothelial electrical resistance (TEER) and horseradish peroxidase (HRP) permeability assays. Western blot and direct fluorescent staining methods were used to detect the tight junction protein expression and F-actin distribution.

RESULTSThe TEER in Bend.3 cells increased with the prolonged culture time and increased to 82.3+/-6.0 Omega cm2 10 days after culture, which was significantly higher than that 3 days after culture (37.3+/-3.1 Omega cm2; P<0.05). There were significant differences in the permeability rates for HRP 3 and 10 days after culture (4.3+/-0.20)% vs (2.2+/-0.05)% (P<0.05). Western blot indicated high level expression of tight junction proteins occludin and ZO-1 in Bend.3 cells 10 days after culture. F-actin was visualized around the cell membrane and presented scrobiculate linear fluorescence 10 days after culture.

CONCLUSIONSBend.3 cells have similar barrier characteristics to BEMC, and their barrier function may reach to the best effect 10 days after culture.

Actins ; analysis ; Animals ; Blood-Brain Barrier ; Cell Line ; Electric Impedance ; Endothelial Cells ; metabolism ; Horseradish Peroxidase ; metabolism ; Membrane Proteins ; analysis ; Mice ; Phosphoproteins ; analysis ; Zonula Occludens-1 Protein

OBJECTIVETo characterize the DNA damage property represented by the distinct whole nucleus stain pattern of gammaH2AX induced by N-methyl-No-nitro-N-nitrosoguanidine (MNNG).

METHODSMNNG-induced gammaH2AX foci formation in human amnion FL cells was observed by immunofluorescent microscopy. DNA double-stranded breaks (DSBs) were detected by neutral comet assay. General DNA damages were detected by alkaline comet assay.

RESULTA distinct whole nucleus stain pattern of gammaH2AX was induced by high concentration MNNG (10 mg/L). 1 mg/L MNNG also induced this type of stain pattern in a small fraction of cells, although the effect was transient. Neutral comet assay did not detect any significant DSBs formation in this type of cells, while alkaline comet assay revealed the presence of DNA damage.

CONCLUSIONAlthough normal gammaH2AX foci were regarded as a biomarker for DSBs, the whole nucleus stain pattern might represent DNA damage other than DSBs.

Amnion ; cytology ; Cell Nucleus ; drug effects ; metabolism ; Comet Assay ; DNA Breaks, Double-Stranded ; drug effects ; DNA Damage ; Histones ; analysis ; Humans ; Methylnitronitrosoguanidine ; pharmacology ; Microscopy, Fluorescence ; Phosphoproteins ; analysis

To evaluate the expression of P120ctn in non-Hodgkin's lymphoma (NHL) and to explore its clinical significance, immunohistochemistry stain method was applied to comparatively investigate the protein expression of P120ctn in paraffin-embedded lymph node tissue slices from 40 cases of NHL and 10 cases of reactive hyperplasia of lymph node. The results showed that P120ctn was not detected in reactive hyperplasia of lymph node, but was detected in 55% (22/40) cases of NHL. P120ctn expression increased with the tumor malignancy of NHL, there was a significant difference between the expression rates of P120ctn in low grade (16.7%, 2/12) and intermediate to high grade malignant (71.4%, 20/28) NHL (P < 0.001). Moreover, P120ctn was also detected in vascular endothelial cells of NHL. It is concluded that the level of P120ctn expression is closely related to the malignant grade of NHL, it suggests that P120ctn possibly plays an important role in the malignant proliferation of lymphoma with a certain significance in diagnosis and therapy of lymphoma.
Adolescent ; Adult ; Aged ; Catenins ; Cell Adhesion Molecules ; analysis ; biosynthesis ; Child ; Female ; Humans ; Immunohistochemistry ; Lymph Nodes ; metabolism ; pathology ; Lymphoma, Non-Hodgkin ; metabolism ; pathology ; Male ; Middle Aged ; Phosphoproteins ; analysis ; biosynthesis

OBJECTIVETo To establish a method of phosphoprotein affinity profiling for identifying phosphoproteomic differences between Thp-1 cells with or without lipopolysaccharide (LPS) stimulation, aiming to screen potential regulators involved in LPS pathway.

METHODSThp-1 cells were stimulated with 100 ng/ml PMA for 48 h to induce differentiation into mature macrophages, which, after culture for another 48 h in the absence of PMA, were either treated with 100 ng/ml LPS for 30 min or left untreated. After desalting procedure with ultrafiltration, the phosphoproteins enriched by phosphoprotein metal affinity column (PMAC) of both groups were run on 2-D electrophoresis to find the spots with different phosphorylation status. Finally, some of these spots were identified by mass spectrometry (MS) and subsequent bioinformatic analysis.

RESULTSCompared to untreated Thp-1 cells, LPS stimulated Thp-1 cells showed 29 spots with reproducible alterations on the 2-D map, including 8 representing up-regulated spots, 7 new spots, 10 down-regulated spots, and 4 absent spots. The newly emerged and absent protein spots were subjected to MS analysis, and 4 of them were identified to be involved in various cellular processes such as proteolysis, signal transduction and protein folding. Among these, phosphorylation of proteasome C2 subunit was dramatically up-regulated in LPS-stimulated cells, as was consistent with previous reports; the phosphorylation of Z-DNA-binding protein 1 has not been reported so far and needs further confirmation.

CONCLUSIONPhosphoprotein affinity profiling is an attractive method for screening novel regulators involved in LPS signaling pathways and can be widely used in systemic study of signal transduction.

Cell Line ; Electrophoresis, Gel, Two-Dimensional ; Humans ; Lipopolysaccharides ; pharmacology ; Macrophages ; cytology ; drug effects ; metabolism ; Mass Spectrometry ; Phosphoproteins ; analysis ; metabolism ; Phosphorylation ; Proteomics ; methods ; Signal Transduction

OBJECTIVETo clone and sequence the upstream of mouse dentin sialophosphoprotein promoter.

METHODSGenomic DNA was obtained from Balb/c mouse blood. The upstream of mouse dentin sialophosphoprotein promoter segments was obtained by PCR. Then the segments were inserted into T-vector. The plasmids were identified by digestion with the restriction enzyme analysis. The positive clone was sequenced and compared with Genebank.

RESULTSThe upstream of mouse dentin sialophosphoprotein promoter was divided into three sequences and three different target segments with 997 bp, 1004 bp and 674 bp in length were obtained. After identified, sequenced and compared with Genebank, the sequences of the segments were consistent with those displayed on Genebank by 99%.

CONCLUSIONThe clone of the upstream of mouse dentin sialophosphoprotein promoter was successful. This work will help to study the regulation of DSPP expression.

Animals ; Cloning, Molecular ; Extracellular Matrix Proteins ; genetics ; Mice ; Mice, Inbred BALB C ; Phosphoproteins ; genetics ; Promoter Regions, Genetic ; Sequence Analysis, DNA ; Sialoglycoproteins ; genetics