Cell organelle proteomics

Figure 2.2. Fractionation of protein extracts before 2D gel electrophoresis. Crude lysates can be fractionated by affinity purification or by a number of chromatographic techniques. In addition, organelles or other cellular structures can be purified and lysates from these organelles can be fractionated or separated directly on 2D gels. By repeating this procedure using a number of conditions it may be possible to visualize a large fraction of a cell s proteome.

Brunet, S., Thibault, P., Gagnon, E., Kearney, P, Bergeron, J.J., Desjardins, M. (2003). Organelle proteomics looking at less to see more. Trends. Cell. Biol. 13, 629-638. 

Cell map proteomics reveals the static proteome of a whole organism, tissue, cell or organelle, while expression proteomics investigates changes in a proteome to cellular cues (Godovac-Zimmermann and Brown, 2001). Functional and structural proteomics refers to the investigation of individual proteins such as interactions with ligands. 

ORGANELLE PROTEOME VARIATION AMONG DIFFERENT CELL TYPES LESSONS FROM NUCLEAR MEMBRANE PROTEINS... 

Organelle Proteome Variation Among Different Cell Types ... 

The human nucleolar proteome also has been characterized (134—136). The results of these studies portray this organelle as extremely metabolically active, with a role in RNA transport and modification, and cell cycle signaling. 

Proteomics is the study of the proteome—defined as the total set of proteins expressed in a given cell type at a given time [27]. Tremendous progress has been made in the past few years in generating large-scale cellular protein profiles, organelle composition, protein activity patterns, and datasets for protein-protein interactions. 

One-step characterization of a eukaryotic cell pro-teome is difficult if not impossible to achieve. There is a growing trend in eukaryotes proteomics toward characterization of subcellular structures. The reason for this shift from global proteomics to subcellular proteomics is the complexity of eukaryotic cells and subcellular organelles. Therefore the proteomic analysis of subcellular organelles will be an important aspect of toxicoproteomics. 

Aside from molecular and biophysical properties of proteins such as mass and charge, all proteins share common attributes that are directly related to the ability or inability to perform global protein analysis. In particular, the spatial context of a particular proteome represents a large part of the complexity for proteomic analysis (Figure 4.3) since total protein expression may relate to an organism, a specific organ, a tissue, a cell, a subcellular organelle, or even biofluid. 

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