Dataset Information

Reproducibility of label-free single-shot phosphoproteomics applied to CRC cell lines

ABSTRACT: There is a need for robust phosphopeptide enrichment methods to allow signaling network analysis in cancer cell lines and tissues with minimal fractionation. With recent instrument developments thousands of unique phosphopeptides can be detected by single-shot LC-MS/MS. However, successful phosphoproteomics experiments still rely on efficient phosphopeptide enrichment from a tryptic digest prior to LC-MS/MS analysis. Here we describe a performance assessment of HAMMOC (hydroxyl acid modified metal affinity chromatography) (Sugiyama MCP2007, Kyono, JPR 2008) combined with single shot label-free quantitation at 500 µg peptide input level. In a triplicate analysis we observe good phosphopeptide identification reproducibility (75.8%), depth of identification (6014-6150 phosphopeptides) and reproducibility of label-free quantification (CV 17.8%, Pearson r 0.87-0.98) by single-shot LC-MS/MS.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Epithelial Cell, Cell Culture

DISEASE(S): Colon Cancer

SUBMITTER: Sander Piersma

LAB HEAD: Connie Ramona Jimenez

PROVIDER: PXD001546 | Pride | 2015-04-15

REPOSITORIES: Pride

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Publications

Feasibility of label-free phosphoproteomics and application to base-line signaling of colorectal cancer cell lines.

Piersma Sander R SR Knol Jaco C JC de Reus Inge I Labots Mariette M Sampadi Bharath K BK Pham Thang V TV Ishihama Yasushi Y Verheul Henk M W HM Jimenez Connie R CR

Journal of proteomics 20150401 Pt B

Robust phosphopeptide enrichment methods with minimal fractionation are required to profile signaling network analysis in cancer cell lines and tissues. We assessed performance of single-shot LC-MS/MS label-free phosphoproteomics using TiOx-based phosphopeptide enrichment and report phosphopeptide identification reproducibility (75.8%), depth of identification (6014-6150 phosphopeptides) and reproducibility of label-free quantification (CV 17.8%). Subsequently, we have profiled the baseline glob ...[more]

PMID: 25841592

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Project description:Spermatogenesis is a complex cell differentiation process that includes marked genetic, cellular functional and structural changes. It requires tight regulation, since disturbances in any of the spermatogenic stages would lead to fertility deficiencies. In order to increase our knowledge of signal transduction during sperm development, we carried out a large-scale identification of the phosphorylation events that occur in the human gonad. Metal oxide affinity chromatography using TiOx combined with LC-MS/MS was conducted to profile the phosphoproteome of human testes with full spermatogenesis. A total of 8187 phosphopeptides derived from 2661 proteins were identified, resulting in the most complete report of human testicular phosphoproteins to date. Phosphorylation events were enriched in proteins functionally related to spermatogenesis, as well as to highly active processes in the male gonad, such as transcriptional and translational regulation, cytoskeleton organization, DNA packaging, cell cycle and apoptosis. Moreover, 174 phosphorylated kinases were identified. The most active and abundant human protein kinases in the testis were predicted both by the phosphorylation status of the kinase activation loop and the number of phosphopeptide spectra identified. The potential function of two of those kinases, cyclin-dependent kinase 12 (CDK12) and p21-activated kinase 4(PAK4), has been explored by protein-protein interaction analysis, immunodetection in human and mouse testicular tissue, and functional assay in a human embryonal carcinoma cell line. The co-localization of CDK12 with Golgi markers and probably pro-acrosomal vesicles suggests a potential crucial role of this protein kinase in sperm formation. PAK4 expression has been found limited to human spermatogonia, and a role in embryonal carcinoma cell response to apoptosis has been observed. Together, our data confirm that phosphoregulation by protein kinases is highly active in sperm differentiation, and open a window to detailed characterization and validation of potential targets for the development of drugs modulating male fertility, and tumor behavior.

Project description:Dendritic cells (DCs) are key initiators of the adaptive immunity, and upon recognition of pathogens are able to skew T cell differentiation to elicit appropriate responses. DCs possess this extraordinary capacity to discern external signals using receptors that recognize pathogen-associated molecular patterns. These can be glycan-binding receptors that recognize carbohydrate structures on pathogens or pathogen-associated patterns that additionally bind receptors, such as Toll-like receptors (TLRs). This study explores the early signaling events in DCs upon binding of α2-3 sialic acid (α2-3sia) that are recognized by Immune inhibitory Sialic acid binding immunoglobulin type lectins. α2-3sias are commonly found on bacteria, e.g. Group B Streptococcus, but can also be expressed by tumor cells. We investigated whether α2-3sia conjugated to a dendrimeric core alters DC signaling properties. Through phosphoproteomic analysis, we found differential signaling profiles in DCs after α2-3sia binding alone or in combination with LPS/TLR4 co-stimulation. α2-3sia was able to modulate the TLR4 signaling cascade, resulting in 109 altered phosphoproteins. These phosphoproteins were annotated to seven biological processes, including the regulation of the IL-12 cytokine pathway. Secretion of IL-10, the inhibitory regulator of IL-12 production, by DCs was found upregulated after overnight stimulation with the α2-3sia dendrimer. Analysis of kinase activity revealed altered signatures in the JAK-STAT signaling pathway. PhosphoSTAT3 (Ser727) and phosphoSTAT5A (Ser780), involved in the regulation of the IL-12 pathway, were both downregulated. Flow cytometric quantification indeed revealed de- phosphorylation over time upon stimulation with α2-3sia, but no α2-6sia. Inhibition of both STAT3 and -5A in moDCs resulted in a similar cytokine secretion profile as α-3sia triggered DCs. Conclusively, this study revealed a specific alteration of the JAK-STAT pathway in DCs upon simultaneous α2-3sia and LPS stimulation, altering the IL10:IL-12 cytokine secretion profile associated with reduction of inflammation. Targeted control of the STAT phosphorylation status is therefore an interesting lead for the abrogation of immune escape that bacteria or tumors impose on the host.

Dataset Information

Reproducibility of label-free single-shot phosphoproteomics applied to CRC cell lines

Publications

Feasibility of label-free phosphoproteomics and application to base-line signaling of colorectal cancer cell lines.

Similar Datasets

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