Imported:YPM/Ste11 num

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

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<modelParameter>Ste11_num = </modelParameter>580 to 3524 molecules/cell

Source

• Quantitative western and FCS.

Trust

• Low

Additional Details

• Ghaemmaghami et al. (2003 PMID 14562106) measured 736/cell by quantitative western of entire proteome.

• By FCS, the cytosolic Ste11 concentration was estimated to be 39 nM. Maeder et al. 2007 PMID 17952059
  • Given a cell volume of 29 fL (see Cell_volume), this corresponds to ~680 molecules per cell.

• By FCS, the cytosolic Ste11 concentration was estimated to be 22 ± 6 nM in the absence of pheromone, and 44 ± 11 nM 2 hours after pheromone treatment. Slaughter et al. 2007 PMID 18077328
  • Assuming that the concentration of Ste11 does not change upon pheromone treatment, and the differences in measured values can be attributed to experimental error, the average concentration is 33 nM.
  • Given a cell volume of 29 fL (see Cell_volume), this corresponds to ~580 molecules per cell.

• Thomson et al. (in preparation) measured 3,524 molecules/cell by careful western blot.

Thomson et al. made careful measurements using purified Ste11 as a protein standard for their Western blots, and accounted for more sources of experimental error than Ghaemmaghami et al. However, there is no reason to suspect the 580-680 molecules per cell measured by Maeder and Slaughter may be erroneous. Thus, all we can say is that the Ste11 abundance likely lies between the 580 and 3,524 molecules/cell.