Quantitative anatomy of a HeLa cell

Range Figure - link % of total cell protein mass
Organism Human Homo sapiens
Reference Itzhak DN, Tyanova S, Cox J, Borner GH. Global, quantitative and dynamic mapping of protein subcellular localization. Elife. 2016 Jun 9 5. pii: e16950. doi: 10.7554/eLife.16950. p.59 figure 3APubMed ID27278775
Method Abstract: "[Investigators] have developed and applied Dynamic Organellar Maps, a proteomic method that allows global mapping of protein translocation events. [They] initially used maps statically to generate a database with localization and absolute copy number information for over 8,700 proteins from HeLa cells, approaching comprehensive coverage. All major organelles were resolved, with exceptional prediction accuracy (estimated at >92%). Combining spatial and abundance information yielded an unprecedented quantitative view of HeLa cell anatomy and organellar composition, at the protein level. [They] subsequently demonstrated the dynamic capabilities of the approach by capturing translocation events following EGF [epidermal growth factor] stimulation, which [they] integrated into a quantitative model."
Comments P.8 bottom paragraph: "Quantitative anatomy of a HeLa cell: Combined knowledge of protein subcellular localization and abundance enables construction of a model of HeLa cell composition. [Investigators] calculated the protein mass of each organelle by multiplying the molecular weights of constituent proteins by their estimated copy numbers (Figure 3). This revealed that the endomembrane system contributes approximately 16% to total cellular protein mass, dominated by mitochondria (6.6%), ER (4.4%), and plasma membrane (3.1%), with relatively minor contributions from endosomes, lysosomes, peroxisomes and Golgi (Figure 3A)." P.45 2nd paragraph: "Figure 3: Quantitative anatomy of a HeLa cell. A) Schematic diagram of a cell where compartments are approximately scaled by their relative contributions to total cell protein mass (not by their volumes). All membranous organelles combined (excluding the nucleus) contribute ca. 16%. For comparison, ribosomes and proteasomes contribute 6% and 1.3%, respectively. The proportion of the ER fraction would increase from 4.4% to ca. 5.4% if attached ribosomes were included."
Entered by Uri M
ID 112703