Extensive analysis of the human platelet proteome by two‐dimensional gel electrophoresis and mass spectrometry

Abstract

Platelets play a key role in the control of bleeding and wound healing, contributing to the formation of vascular plugs. Under pathologic circumstances, they are involved in thrombotic disorders, including heart disease. Since platelets do not have a nucleus, proteomics offers a powerful alternative approach to provide data on protein expression in these cells, helping to address their biology. In this publication we extend the previously reported analysis of the pI 4-5 region of the human platelet proteome to the pI 5-11 region. By using narrow pI range two-dimensional electrophoresis (2-DE) for protein separation followed by high-throughput tandem mass spectrometry (MS/MS) for protein identification, we were able to identify 760 protein features, corresponding to 311 different genes, resulting in the annotation of 54% of the pI 5-11 range 2-DE proteome map. We evaluated the physicochemical properties and functions of the identified platelet proteome. Importantly, the main group of proteins identified is involved in intracellular signalling and regulation of the cytoskeleton. In addition, 11 hypothetical proteins are reported. In conclusion, this study provides a unique inventory of the platelet proteome, contributing to our understanding of platelet function and building the basis for the identification of new drug targets.

Recent advances in blood‐related proteomics

“…Surprisingly, transcription factors, elongation factors, and centromer proteins, whose functions in platelets are all but clear, were also identified [118]. In another study, Garcia et al [119] separately analyzed the pI 4-5 region and pI 5-11 regions of the human platelet proteome, and identified 311 gene products. The largest group of these proteins expressed signal transduction functions.…”

What Can Proteomics Tell Us About Platelets?

“…In one study, proteins from resting and collagen receptor-stimulated platelets were incubated with cAMP/cGMP-coupled beads, and the pull-down eluates were analyzed by LC-MS/MS. 115 Owing to the enrichment provided by specific probes, activity-based protein profiling 116-121 B, These studies are mainly (40%) based on 2-dimensional gel electrophoresis (2-DE)/ difference gel electrophoresis (DIGE), 46,52,53,80,82,83,85,87,88,90,91,[93][94][95][96]98,102,106,110,112,113 whereas gelfree methods (23%) are still under-represented. 21,42,89,97,[114][115][116][117][118]121 Combination refers to studies using 2-DE/DIGE in combination with other approaches.…”

The Human Platelet Membrane Proteome Reveals Several New Potential Membrane Proteins

“…As a consequence in all platelet proteome studies based on 2D-PAGE, membrane proteins such as receptors are almost completely missing apart from the high abundant glycoproteins, e.g. GPIIb/IIIa and GPIb, which could be identified in these studies (5,6). Furthermore, dynamic range is another important aspect with regard to the achievable proteome coverage.…”