Subproteome analysis of the neutrophil cytoskeleton

Abstract

Neutrophils play a key role in the early host-defense mechanisms due to their capacity to migrate into inflamed tissues and phagocytose microorganisms. The cytoskeleton has an essential role in these neutrophil functions, however, its composition is still poorly understood. We separately analyzed different cytoskeletal compartments: cytosolic skeleton, phagosome membrane skeleton, and plasma membrane skeleton. Using a proteomic approach, 138 nonredundant proteins were identified. Proteins not previously known to associate with the skeleton were: n-acetylglucosamine kinase, phosphoglycerate mutase 1, prohibitin, ficolin-1, phosphogluconate dehydrogenase, glucosidase, transketolase, major vault protein, valosin-containing protein, aldehyde dehydrogenase, and lung cancer-related protein-8 (LCRP8). The majority of these proteins can be classified as energy metabolism enzymes. Such a finding was interesting because neutrophil energy metabolism is unusual, mainly relying on glycolysis. The enrichment of phosphoglycerate mutase in cytosolic skeleton was additionally indicated by the use of Western blotting. This is the broadest subcellular investigation to date of the neutrophil cytoskeletal proteome and the first proteomic analysis in any cell type of the phagosome skeleton. The association of metabolic enzymes with cytoskeleton is suggestive of the importance of their localized enrichment and macromolecular organization in neutrophils.

The Fc receptor-cytoskeleton complex from human neutrophils

“…There is little direct mass spectrometric data for the cytoskeleton proteins of the phagocytic receptors [4,6,7]. Remodeling of the cytoskeleton plays an important role in phagocytosis and is regulated by a large variety of different proteins [8,9].…”

Quantitative Organelle Proteomics of MCF-7 Breast Cancer Cells Reveals Multiple Subcellular Locations for Proteins in Cellular Functional Processes

“…[24][25][26][27][28] The most common approach has been purification of individual organelles followed by exhaustive determination of the protein content. The main disadvantages of this approach are that the degree of purification/ contamination of the organelle is difficult to ascertain conclusively for lower abundance proteins, that the protein content may be altered by the purification process and that the approach is not very suitable for dynamic studies of protein subcellular location.…”

Proteomic and Metabolomic Profiles in Atherothrombotic Vascular Disease

“…Interestingly, serum chitotriosidase activity has been associated with the extent of coronary artery disease [23]. A recent study has undertaken a subproteome analysis of PMN cytoskeleton, due to the essential role that cytoskeleton plays in PMN functions [24]. Classic proteomic tools were applied to different cellular compartments, in order to reduce the complexity of the sample.…”