Imported:YPM/Ste5 num

Category:Parameters - Yeast Pheromone Response Model Back to main model page

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<modelParameter>Ste5_num = 560</modelParameter> molecules/cell

Source

• Quantitative immunoblotting analysis and FCS.

Trust

• Medium

Additional Details

• Ghaemmaghami et al. (2003 PMID 14562106) measured 1900/cell by quantitative immunoblotting during global analysis of entire proteome.

• By FCS, the cytosolic Ste5 concentration was estimated to be 35 nM. Maeder et al. 2007 PMID 17952059
  • Given a cell volume of 29 fL (see Cell_volume), this corresponds to ~610 molecules per cell.

• By FCS, the cytosolic Ste5 concentration was estimated to be 28 ± 6 nM in the absence of pheromone, and 39 ± 6 nM 2 hours after pheromone treatment. Slaughter et al. 2007 PMID 18077328
  • Assuming that the concentration of Ste5 does not change upon pheromone treatment, and the differences in measured values can be attributed to experimental error, the average concentration is 33.5 nM.
  • Given a cell volume of 29 fL (see Cell_volume), this corresponds to ~590 molecules per cell.

• Thomson et al. (in preparation) measured 484 molecules/cell by careful western blot.

Thomson et al. made careful measurements using known amounts of purified Ste5 as a protein standard for their Western blots, and accounted for more sources of experimental error than Ghaemmaghami et al. Additionally, the measurements made by Maeder et al and Slaughter et al. using an orthogonal method (FCS) agree well with the measurements of Thomson et al. but not with the measurements of Ghaemmaghami et al. Thus, we average the measurements of Thomson, Maeder and Slaughter to get 560 molecules/cell.